A biological deodorization treatment system and a treatment method thereof

Abstract

The application discloses a biological deodorization treatment system and a treatment method thereof. The system comprises a biological deodorization tank, a fan, a chimney, a multi-section differential pressure monitoring assembly, an instrument system and a PLC controller. The instrument system comprises a filler layer temperature and inlet gas temperature sensor, a pH sensor, a circulating liquid conductivity sensor and an inlet and outlet gas concentration sensor. The PLC controller calculates a metabolic activity heat index according to the temperature difference between the filler layer and the inlet gas, and calculates a removal rate according to the inlet and outlet concentrations. When the removal rate decreases and the differential pressure increases, it is determined that the system is blocked and the maintenance is performed. When the removal rate decreases and the differential pressure is normal, or the metabolic activity heat index is effective and narrowed, it is determined that the system is active and the maintenance is performed. The alkali dosage is determined according to the pH change rate, the acidification source is distinguished according to the conductivity, the outlet concentration change rate is used as a warning sign of exceeding the standard, and the system is closed-loop reviewed. The application senses the activity of the bacterial population by the metabolic activity heat index, and is suitable for the treatment of malodors in sewage plants, waste stations, breeding farms and the like.

Description

Technical Field

[0001] This invention belongs to the field of odor control technology, specifically relating to a biological deodorization system and its treatment method. Background Technology

[0002] The core of the biological deodorization system is the biological deodorization box (biological filter), which is filled with porous packing material with a large specific surface area. The surface of the packing material is covered with acclimatized and cultured functional microorganisms (such as sulfur oxidizing bacteria, nitrifying bacteria, etc.).

[0003] Biological deodorization chambers face several operational challenges during long-term use: First, the packing layer becomes clogged, trapping dust particles in the intake air. Excessive biofilm growth and the accumulation of aged biofilm lead to increased pressure differential within the packing layer, decreased airflow, and reduced deodorization efficiency. Second, microbial activity fluctuates. In winter, low temperatures, nutrient imbalances, abnormal pH levels, or shock loads significantly reduce the metabolic activity of microorganisms on the packing surface, resulting in decreased deodorization efficiency and even exceeding emission standards. Third, moisture imbalance occurs. When the packing layer is too dry, the microorganisms dehydrate and die; when it is too wet, localized anaerobic zones form, generating foul odors. These interconnected problems collectively constitute the operational bottleneck of biological deodorization chambers.

[0004] Chinese patent document CN112023683A discloses an anti-clogging biofilter for odor purification, including a pre-washing tank and a biofilter. An ozone water flushing device is installed on the side of the biofilter, and pressure gauges are installed at both the inlet and outlet of the biofilter to monitor the packing material blockage. When blockage is detected, a motor is activated to open a baffle, and a three-axis robotic arm extends above or below the packing material to flush the blocked packing material with high-concentration ozone water. This solution requires pre-setting two pressure gauge measuring points at the inlet and outlet, and can only determine whether blockage has occurred but cannot pinpoint the specific location of the blockage in the packing layer. Furthermore, maintenance relies on the three-axis robotic arm in conjunction with ozone water flushing, requiring the opening and closing of the side baffle, resulting in a complex structure, inability to perform online maintenance, and the use of a single ozone water flushing method cannot differentiate the cause of the blockage for targeted treatment.

[0005] Chinese patent document CN109692555A discloses an integrated biological deodorization device and method, including a biological reaction unit, a detection unit, an electrical control and transmission display unit, and a power source unit. The detection unit includes a differential pressure gauge, a temperature and humidity meter, a pH meter, and other detection components for detecting the pressure difference between the inlet and outlet. The electrical control and transmission display unit uses a PLC controller to achieve on-site monitoring and display as well as remote control display. This solution discloses the detection and data acquisition functions of multiple parameters, but the differential pressure detection is limited to the inlet and outlet, and multi-section differential pressure monitoring is not disclosed. The control logic is mainly based on data acquisition, display, and remote control, but the specific discrimination algorithm based on multi-parameter coupling to determine the blockage type and implement cause-and-effect solutions is not disclosed.

[0006] Chinese patent document CN104353353A discloses a bio-trickling filter with automatic regulation of microbial distribution. It uses four electrically operated ventilation disc valves connected to a PLC installed on the inlet and outlet pipes to control the alternating air intake from the upper and lower ends, ensuring uniform distribution of microorganisms on the packing layer. While this method indirectly prevents excessive biofilm growth in a specific area by changing the airflow direction, the air intake switching is timed and not based on differential pressure diagnosis for targeted maintenance. Therefore, it cannot address blockages caused by dust, dry caking, or other factors.

[0007] Utility model patent CN223209278U discloses an integrated multi-stage anti-clogging biological deodorization and purification device. It features a pressure sensor in each of the left and right treatment chambers. The backwashing device is triggered when the pressure inside the chamber exceeds a set value, activating the backwashing device to flush the biological packing bed. However, this design only uses pressure difference measurement points in the left and right chambers and the triggering condition is a single threshold, making it unable to locate the blockage or determine the type of blockage.

[0008] In addition, there are solutions in the field of odor gas treatment that use online gas concentration monitoring for feedback control. One example is an automated, high-efficiency biological deodorization reactor with an online hydrogen sulfide gas detector installed at the inlet and online hydrogen sulfide and ammonia gas detectors installed on the exhaust device. Each online monitoring point is connected to a PLC control system. Another example is a novel intelligent composite odor gas treatment device with two online gas monitoring feedback units at the inlet and outlet of the inlet pipe. The electronic control unit controls the start-up and shutdown combinations of multiple gas treatment units, the opening angle of the airflow control valve, and the opening direction of the three-way diverter valve based on the gas composition and concentration. These solutions disclose a feedback control method that uses online monitoring of inlet and outlet gas concentrations to perform macroscopic process switching or airflow adjustment. However, their control object is the process combination switching of multi-stage treatment units, which is a macroscopic level of process allocation. Furthermore, none of these solutions disclose the joint decoupling and discrimination of removal rate and pressure difference for differentiating between clogging and activated efficiency declines in single-stage biological filters and for differentiated maintenance.

[0009] The aforementioned existing technologies all have the following shortcomings: First, the differential pressure monitoring points are all located at two locations (inlet / outlet or left / right chamber), making it impossible to locate blockages at different locations within the packing layer; second, maintenance decisions rely solely on physical indicators such as differential pressure, failing to reflect the actual degradation capacity of the microbial community. When microbial activity decreases (e.g., due to low temperature, nutrient imbalance, or poisoning) while the differential pressure remains normal, excessive emissions at the outlet go undetected; third, the perception of microbial activity depends on online gas concentration meters, which are costly, difficult to maintain, and have a slow response time. Most projects lack these meters, resulting in a lack of activity monitoring, and they do not utilize the exothermic characteristics of microbial degradation. The system fails to detect bacterial activity at low cost due to temperature differences; it cannot distinguish between blockage and activity-related causes when efficiency declines, leading to incorrect maintenance actions; it cannot differentiate the sources of circulating water acidification (sulfur-type acidification and nitrification-type acidification mechanisms are different), and there is a detection lag in alkali dosing, which can easily cause oscillations and secondary disturbances to the bacterial community if the alkali dosing is inaccurate; the effectiveness of maintenance actions such as backwashing is evaluated only based on pressure difference recovery, which cannot quantitatively assess the recovery of bacterial degradation capacity; and it lacks early warning of excessive outlet concentrations, only providing post-event alarms, which can easily lead to instantaneous discharge exceeding standards due to occasional high-concentration shocks. Summary of the Invention

[0010] (a) Technical problems to be solved To address the shortcomings of existing biological deodorization systems, such as relying solely on physical indicators like pressure difference for maintenance decisions (failing to detect actual bacterial activity), lack of low-cost detection methods for exceeding emission standards when bacterial activity declines (due to low temperature, poisoning, or nutrient imbalance), inaccurate alkali dosing due to the inability to distinguish the source of circulating water acidification leading to detection lag, and the inability to provide post-event alarms for exceeding outlet concentration standards without early warning, the first objective of this invention is to provide a biological deodorization system. This system constructs a metabolic activity thermal index by adjusting the temperature difference between the packing layer and the inlet air temperature. Combined with the removal rate calculated from the inlet and outlet gas concentrations, it forms a dual-channel bacterial activity monitoring system. A PLC controller uses the removal rate, pressure difference, and metabolic activity thermal index to decouple and determine the type of efficiency decline. It also uses pH change rate as a time-limited quantitative feedforward and circulating liquid conductivity to distinguish the source of acidification for precise alkali dosing. Furthermore, it provides early warning based on the upward trend of outlet concentration, achieving precise perception and intelligent maintenance of the bacterial state in the biological deodorization system.

[0011] The second objective of this invention is to provide a biological deodorization treatment method, which includes steps such as multi-section differential pressure acquisition, calculation of metabolic activity heat index and removal rate, decoupling and discrimination of efficiency decline type, differentiated maintenance, precise alkali dosing, early warning of exceeding the standard, and evaluation of removal rate recovery, so as to achieve precise maintenance of the microbial health of the biological deodorization system.

[0012] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A biological deodorization system includes a biological deodorization chamber, a centrifugal fan, and a chimney. The biological deodorization chamber includes a chamber body, a packing layer, a spray assembly, and a drainage tank disposed within the chamber. It also includes a multi-section differential pressure monitoring assembly arranged along the airflow direction in the packing layer, comprising at least four pressure measuring points, with adjacent pressure measuring points forming a differential pressure measurement section; an instrumentation system for detecting the packing layer temperature, inlet air temperature, inlet gas concentration, outlet gas concentration, circulating liquid pH value, circulating liquid conductivity, and packing layer moisture content; and an execution component including a circulating water pump, a backwash valve, an alkali dosing pump, a nutrient solution dosing pump, and a circulating liquid return pipeline on the main spray pipeline. The circulating liquid return pipeline connects the drainage tank and the circulating water tank; the circulating water collected in the drainage tank returns to the circulating water tank via the circulating liquid return pipeline, forming a closed-loop circulation of spray circulating water with the circulating water pump, the main spray pipeline, the spray assembly, and the packing layer; and the input terminal of a PLC controller is connected to the signals of the multi-section differential pressure monitoring assembly and the instrumentation system. The output is connected to the actuator and centrifugal fan control; the PLC controller is configured to calculate the metabolic activity heat index based on the difference between the packing layer temperature and the inlet air temperature, calculate the removal rate based on the inlet and outlet gas concentrations, and locate the blockage position based on the pressure difference value and change rate of each pressure difference measurement section; when the removal rate decreases and the pressure difference increases, it is determined to be a blockage type and triggers flushing and maintenance; when the removal rate decreases and the pressure difference is normal, it is determined to be an activity type and triggers maintenance; when the metabolic activity heat index is in an effective state and narrows, it is also determined to be an activity type and triggers maintenance; the alkali dosage is determined based on the circulating liquid pH value and change rate feedforward and combined with conductivity to distinguish the acidification source, and the feedforward alkali dosage limits the duration and dosage; when the outlet concentration shows an upward trend and the change rate exceeds the threshold, it issues an early warning of exceeding the standard, and evaluates the maintenance effect based on the removal rate recovery status for closed-loop verification.

[0013] The instrument system includes a packing layer moisture content sensor, a packing layer temperature sensor, an inlet air temperature sensor, a pH sensor, a circulating liquid conductivity sensor, an inlet gas concentration sensor, and an outlet gas concentration sensor. The packing layer moisture content sensor and the packing layer temperature sensor are located inside the packing layer, the inlet air temperature sensor is located on the inlet air duct, the pH sensor and the circulating liquid conductivity sensor are located on the circulating liquid return pipeline between the drain tank and the circulating water tank, the inlet gas concentration sensor is located on the inlet air duct, and the outlet gas concentration sensor is located on the purified gas pipeline.

[0014] The multi-section differential pressure monitoring component has four to six pressure measuring points, which are arranged at equal or unequal intervals along the airflow direction. The differential pressure measuring section includes a first differential pressure measuring section located between the first and second pressure measuring points, a second differential pressure measuring section located between the second and third pressure measuring points, and a third differential pressure measuring section located between the third and fourth pressure measuring points.

[0015] This includes a backwash pipeline, backwash nozzles, a backwash regulating valve, and a spray regulating valve. One end of the backwash pipeline is connected to the outlet of the circulating water pump, and the other end extends to the air inlet side of the packing layer and connects to the backwash nozzle. The backwash valve is located on the backwash pipeline, and the spray direction of the backwash nozzle is upward along the reverse airflow direction. The nozzles of the spray assembly are arranged above the air outlet side of the packing layer and spray downward. The backwash regulating valve is located on the backwash pipeline, and the spray regulating valve is located on the main spray pipeline. When the backwash valve is open, it is controlled by PL. The C controller adjusts the opening of the backwash regulating valve and the spray regulating valve to distribute the two flow rates. During flushing and maintenance, the backwash valve and the circulating water pump are opened simultaneously. The backwash nozzles spray circulating water against the airflow direction on the air inlet side of the packing layer to directly disperse the dust particles deposited on the air inlet side. The spray assembly sprays circulating water in the airflow direction on the air outlet side to flush the surface of the packing layer. The two-way water flow converges and flushes within the packing layer, peeling the blockages inside the packing layer from the pores of the packing layer and discharging them from the drain tank with the water flow. After flushing is completed, the backwash valve is closed to restore normal operation.

[0016] The PLC controller is also configured to perform temperature correction and validity criteria for the metabolic activity thermal index: the sliding average of the difference between the packing layer temperature and the inlet air temperature within a preset sliding window period is used as the criterion value for the metabolic activity thermal index, eliminating the interference of diurnal fluctuations in the inlet air temperature; when the inlet air temperature is within the preset normal operating temperature range, the metabolic activity thermal index serves as an effective criterion for monitoring bacterial activity; when the inlet air temperature exceeds the preset normal operating temperature range, the metabolic activity thermal index is downgraded to a reference signal, and the type of efficiency decline is determined only based on the removal rate; the narrowing of the metabolic activity thermal index is not considered as an indicator of activity efficiency. Independent criteria for decline; constructing a dual-channel microbial activity monitoring system using metabolic activity thermal index and removal rate: when the metabolic activity thermal index is in an effective state, a decline in microbial activity is determined when the metabolic activity thermal index narrows and the removal rate decreases; when the metabolic activity thermal index is in an effective state, and the metabolic activity thermal index narrows while the detection value of the outlet gas concentration sensor is normal, the metabolic activity thermal index is used as the basis for maintenance decisions and a nutrient supplementation or heat preservation prompt is output; when the inlet gas concentration sensor or outlet gas concentration sensor malfunctions or is calibrated, the metabolic activity thermal index is used instead of the removal rate as the microbial activity monitoring signal.

[0017] This invention also provides a biological deodorization treatment method, applied to the aforementioned biological deodorization treatment system, comprising the following steps: collecting the differential pressure values ​​of each differential pressure measuring section, as well as the detection values ​​of the packing layer temperature, inlet air temperature, inlet gas concentration, outlet gas concentration, circulating liquid pH value, circulating liquid conductivity, and packing layer moisture content; locating the blockage location of the packing layer based on the differential pressure values ​​and differential pressure change rate of each differential pressure measuring section, and calculating the metabolic activity heat index and removal rate; determining the type of efficiency decline by combining the removal rate, differential pressure, and metabolic activity heat index; when the efficiency decline is determined to be blockage-type, the circulating water pump and backwash valve are activated to perform flushing maintenance, during which the backwash valve is opened, and circulating water is sprayed against the airflow direction on the inlet side through the backwash nozzle, while the spray assembly sprays in the airflow direction on the outlet side, forming a bidirectional flushing stripping and discharging of the blockage in the packing layer; when the efficiency decline is determined to be activity-type, activity maintenance is activated; after the maintenance action is completed, the maintenance effect is evaluated based on the removal rate recovery and a closed-loop review is performed, and an early warning of exceeding the standard is issued when the outlet concentration shows an upward trend and the change rate exceeds the threshold.

[0018] The data acquisition steps also include: collecting pressure signals at each pressure measurement point along the airflow direction in the packing layer, and simultaneously collecting the detection values ​​of the inlet gas concentration sensor, outlet gas concentration sensor, packing layer temperature sensor, inlet air temperature sensor, pH sensor, and circulating liquid conductivity sensor; using the sliding average value of the difference between the packing layer temperature and the inlet air temperature within a preset sliding window period as the criterion value for the metabolic activity heat index, and the removal rate is equal to one minus the ratio of the outlet concentration to the inlet concentration.

[0019] The blockage location locating step further includes: calculating the proportion of the pressure difference of each pressure differential measurement segment to the total pressure difference between the first and last pressure measurement points along the airflow direction, thus obtaining the pressure difference proportion of each pressure differential measurement segment; when the pressure difference proportion of the first pressure differential measurement segment is greater than the first proportion threshold and the duration is greater than the first duration threshold, it is determined that the air inlet side of the packing layer is blocked; when the pressure difference proportion of the second pressure differential measurement segment is greater than the second proportion threshold and the duration is greater than the second duration threshold, it is determined that the middle section of the packing layer is blocked; when the pressure difference proportion of the third pressure differential measurement segment is greater than the third proportion threshold and the duration is greater than the third duration threshold, it is determined that the air outlet side of the packing layer is blocked.

[0020] The efficiency degradation type discrimination step further includes: comparing the removal rate, the differential pressure value of each differential pressure measurement segment, and the metabolic activity heat index. When the removal rate is lower than the preset removal rate threshold and the differential pressure value or differential pressure ratio of any differential pressure measurement segment exceeds the corresponding threshold, it is judged as a blockage-type efficiency degradation. When the removal rate is lower than the preset removal rate threshold and the differential pressure value of each differential pressure measurement segment does not exceed the corresponding threshold, or the metabolic activity heat index is in an effective state and narrows, it is judged as an activity-type efficiency degradation. The temperature detection value of the packing layer temperature sensor, the moisture content detection value of the packing layer moisture content sensor, the pH detection value of the pH sensor, and the conductivity detection value of the circulating liquid conductivity sensor are input into the preset activity maintenance discrimination rules, and at least one activity maintenance type is output from low temperature and low activity, shock load, packing drying, and packing layer acidification. When the inlet air temperature exceeds the preset normal operating temperature range, causing the metabolic activity heat index to be in a degraded state, the narrowing of the metabolic activity heat index is not used as an independent criterion for activity-type efficiency degradation. Only the low removal rate and normal differential pressure are used as the criteria for determining activity type.

[0021] The method also includes precise alkali dosing, early warning of exceeding standards, and assessment of removal rate recovery: The pH decrease rate is calculated based on the rate of change of the pH sensor readings. When the pH decrease rate exceeds a preset threshold, it is determined to be rapid acidification, and time-limited quantitative feedforward alkali dosing is implemented. This means increasing the dosage of the alkali solution pump based on the pH decrease rate, ensuring the dosing duration does not exceed a preset time limit and the cumulative dosage does not exceed a preset dose limit. After reaching the preset time limit, feedforward alkali dosing is paused and reassessed. When the pH decrease rate is within the normal range, the acidification source is distinguished based on the circulating liquid conductivity sensor readings. When conductivity increases and pH decreases, it is determined to be sulfur-type acidification, and alkali solution is added to neutralize sulfuric acid. When the increase in conductivity is less than the decrease in pH, it is determined to be nitration-type acidification, and alkali solution is added appropriately, along with bicarbonate to supplement alkalinity. Based on the outlet gas... The concentration sensor calculates the outlet concentration change rate based on the detected value. When the outlet concentration shows an upward trend within a continuous sampling period and the rate of increase exceeds a preset change rate threshold, but the outlet concentration has not yet exceeded the emission standard, it is determined that there is a precursor to exceeding the standard. This triggers a reduction in the centrifugal fan speed to extend the gas residence time in the packing layer and an increase in the output flow of the circulating water pump to enhance spray absorption. After maintenance is completed, the removal rate recovery rate is calculated, and the decline in the removal rate is monitored simultaneously. When the removal rate recovery rate is greater than a preset upper threshold and the removal rate is stable without decline, the maintenance is deemed effective. When the removal rate recovery rate is between a preset lower threshold and a preset upper threshold, the maintenance is deemed insufficient, and an increased maintenance intensity prompt is output. When the removal rate recovery rate is less than a preset lower threshold, or the removal rate recovers and then rapidly declines or fluctuates, the maintenance is deemed excessive, and a reduced maintenance intensity prompt is output.

[0022] (III) Beneficial Effects The beneficial effects of this invention are as follows: This invention constructs a metabolic activity thermal index by measuring the temperature difference between the packing layer and the inlet air temperature. Utilizing the exothermic characteristics of the microbial degradation process, it reflects the metabolic intensity of the microbial community in real time. This allows for low-cost perception of changes in microbial activity without the need for an online gas concentration meter, directly addressing the technical pain points of existing technologies that rely on expensive concentration meters and are often not installed in most projects, leading to a lack of awareness of decreased microbial activity. By applying a moving average temperature correction to the metabolic activity thermal index and setting an effective temperature range criterion, the interference of seasonal and diurnal temperature differences on the judgment of microbial activity is eliminated, avoiding misjudgment of microbial activity loss in low-temperature seasons and masking of activity decline in high-temperature seasons. The metabolic activity thermal index and removal rate constitute a dual-channel microbial activity monitoring system, with the metabolic activity thermal index serving as a fallback in case of concentration meter failure or calibration, ensuring continuous monitoring.

[0023] This invention uses a multi-indicator decoupling and discrimination method, combining removal rate, pressure difference, and metabolic activity thermal index, to accurately distinguish between two causes of efficiency decline: blockage and activity. When the efficiency decline is of the activity type, the maintenance type is further subdivided based on temperature, moisture content, pH, and conductivity. This overcomes the technical defects of existing technologies that rely solely on pressure difference and cannot detect the decline in bacterial activity, and that maintenance actions are easily misselected.

[0024] This invention distinguishes the source of acidification by using pH change rate-limited quantitative feedforward alkali dosing and circulating liquid conductivity to compensate for the lag in circulating water detection pipelines. It also avoids excessive alkali dosing during shock acidification by setting upper limits for dosing duration and dosage. Furthermore, it differentiates between sulfur-type and nitrification-type acidification and adopts differentiated alkali dosing strategies to achieve precise alkali dosing, avoiding secondary disturbances to the microbial community caused by alkali dosing fluctuations and excessive alkali dosing. This overcomes the shortcomings of existing technologies that only dos alkali according to pH thresholds without differentiation.

[0025] This invention provides early warning of emissions exceeding standards using both the upward trend and rate of change of the outlet concentration. It only identifies an early warning when the outlet concentration shows an upward trend and the rate of increase exceeds a threshold, avoiding false alarms caused by a rapid decrease in concentration during normal recovery. When the outlet concentration has not yet exceeded the standard but the upward trend is abnormal, it proactively reduces the air volume and strengthens the spray absorption, elevating the prevention of emissions exceeding standards from post-event alarms to early warning, directly addressing the core requirement of instantaneous compliance supervision of exhaust gas emissions. Furthermore, it monitors the conductivity of the circulating liquid to detect early signs of aging biofilm detachment, preventing sudden detachment from causing instantaneous emissions exceeding standards.

[0026] This invention utilizes a bidirectional flushing system, consisting of a backflushing pipeline and a backflushing nozzle spraying against the airflow direction on the air inlet side of the packing layer, and a spraying assembly spraying in the airflow direction on the air outlet side. This system can directly disperse dust particles deposited on the air inlet side and remove blockages inside the packing layer, overcoming the technical defect of existing technologies that only flush from the top in the direction of the airflow, resulting in incomplete removal of dust blockages on the air inlet side.

[0027] The method and system of this invention work together, relying on the same set of multi-section differential pressure monitoring components, the same temperature and concentration monitoring, the same circulating liquid conductivity monitoring, the same dosing system and the same PLC controller to achieve functions such as precise perception of bacterial community status, decoupling and identification of efficiency decline types, precise alkali dosing, early warning of exceeding standards, and assessment of removal rate recovery. It can achieve precise maintenance of bacterial community health without the need to add independent mechanical devices. It has a compact structure, controllable cost, and precise maintenance, and is particularly suitable for the treatment of odorous gases in municipal sewage treatment plants, sludge treatment workshops, garbage transfer stations, livestock and poultry farms and other places. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the process principle of a biological deodorization treatment system according to the present invention; Figure 2 This is a schematic diagram showing the arrangement of the multi-section differential pressure monitoring component of the present invention in the packing layer; Explanation of reference numerals in the attached figures: 1-Biological deodorization treatment system; 2-Biological deodorization box; 21-Box body; 22-Packaging layer; 23-Air inlet and distribution assembly; 24-Drainage tank; 25-Spray assembly; 3-Multi-section differential pressure monitoring assembly; 31-First pressure measuring point; 32-Second pressure measuring point; 33-Third pressure measuring point; 34-Fourth pressure measuring point; 4-Pre-wash section; 41-Pre-wash spray pipe; 5-Centrifugal fan; 6-Chimney; 7-Circulating water system; 71-Circulating water tank; 72-Circulating water pump; 73-Spray main pipeline ; 74-Backwash valve; 75-Backwash pipeline; 76-Backwash nozzle; 77-Backwash regulating valve; 78-Spray regulating valve; 79-Circulating liquid return pipeline; 8-Dosing system; 81-Alkali dosing pump; 82-Nutrient solution dosing pump; 91-Packaging layer temperature sensor; 92-Packaging layer moisture content sensor; 93-pH sensor; 94-Inlet air temperature sensor; 95-Inlet gas concentration sensor; 96-Outlet gas concentration sensor; 100-Circulating liquid conductivity sensor. Detailed Implementation

[0029] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0030] Example 1

[0031] This embodiment describes a biological deodorization system. For example... Figure 1 and 2As shown, this embodiment provides a biological deodorization system including a biological deodorization chamber 2, a centrifugal fan 5, and a chimney 6. The biological deodorization chamber 2 has a chamber body 21, a packing layer 22, an air inlet and distribution assembly 23, an air outlet assembly, a spray assembly 25, and a drainage tank 24. The chamber body 21 is made of fiberglass, with an insulation layer and a protective layer on the outer wall, suitable for the high humidity and highly corrosive operating environment of sewage treatment plants. The packing layer 22 is filled inside the chamber body 21, filled with porous organic or inorganic packing materials with a large specific surface area (such as ceramsite, activated carbon, volcanic rock, polyurethane hollow spheres, or a combination thereof). The surface of the packing material is covered with acclimatized and cultured functional microorganisms (such as sulfur-oxidizing bacteria, nitrifying bacteria, etc.). The air inlet and distribution assembly 23 is located at the bottom of the chamber body 21, used to evenly distribute the odorous gas after pre-washing section 4 to the bottom of the packing layer 22. The air outlet assembly is located at the top of the chamber body 21, used to collect the purified gas and connect it to the centrifugal fan 5. The spray assembly 25 is located on the top of the housing 21 and is used to spray circulating water onto the packing layer 22 to maintain the moisture content of the packing layer.

[0032] A drain tank 24 is located at the bottom of the housing 21 to collect circulating water that has flowed through the packing layer 22. The circulating water tank 71 is connected to the drain tank 24 via a circulating liquid return pipe 79. The circulating water collected in the drain tank 24 returns to the circulating water tank 71 via the circulating liquid return pipe 79, forming a closed-loop circulation of the spray circulating water with the circulating water pump 72, the main spray pipe 73, the spray assembly 25, and the packing layer 22. The circulating water tank 71 is also connected to a water replenishment device (such as a tap water or reclaimed water replenishment valve, not shown in the figure) to compensate for losses caused by evaporation, water retention in the packing layer, and sewage discharge, maintaining a stable liquid level in the circulating water tank 71. The centrifugal fan 5 is a variable frequency fan, located between the exhaust assembly and the chimney 6, used for negative pressure suction of odorous gases and its speed can be adjusted according to control commands to change the processing air volume.

[0033] Specifically, the multi-section differential pressure monitoring component 3 is arranged inside the packing layer 22 along the airflow direction, including at least four pressure measuring points: a first pressure measuring point 31 arranged on the inlet side, a second pressure measuring point 32 arranged in the middle section or on the inlet side, a third pressure measuring point 33 arranged on the outlet side, and a fourth pressure measuring point 34 arranged on the outlet component side. The first pressure measuring point 31 and the second pressure measuring point 32 constitute the first differential pressure measuring section, the second pressure measuring point 32 and the third pressure measuring point 33 constitute the second differential pressure measuring section, and the third pressure measuring point 33 and the fourth pressure measuring point 34 constitute the third differential pressure measuring section. Each pressure measuring point adopts a flush diaphragm anti-clogging pressure transmitter, and its diaphragm is installed flush with the inner wall of the packing layer at the opening on the side wall of the housing 21.

[0034] The instrumentation system includes a packing layer moisture content sensor 92, a packing layer temperature sensor 91, an inlet air temperature sensor 94, a pH sensor 93, a circulating liquid conductivity sensor 100, an inlet gas concentration sensor 95, and an outlet gas concentration sensor 96. Specifically, the packing layer moisture content sensor 92 and the packing layer temperature sensor 91 are located inside the packing layer 22 and are used to detect the mass moisture content and temperature of the packing layer 22 in real time; the inlet air temperature sensor 94 is located on the inlet air duct and is used to detect the temperature of the odorous gas before it enters the biological deodorization box 2; the pH sensor 93 is located on the circulating liquid return pipe 79 between the drain tank 24 and the circulating water tank 71 and is used to detect the pH value of the circulating liquid in real time; the circulating liquid conductivity sensor 100 is located on the circulating liquid return pipe 79 between the drain tank 24 and the circulating water tank 71. The liquid return pipeline 79 is used to detect the conductivity of the circulating liquid in real time, reflecting the ion concentration and the content of sloughed-off products of the aging biofilm in the circulating liquid; the inlet gas concentration sensor 95 is set on the air inlet duct to detect the concentration of malodorous components such as H2S and N3H in the odorous gas before entering the biological deodorization box 2; the outlet gas concentration sensor 96 is set on the purified gas pipeline between the outlet assembly and the chimney 6 to detect the concentration of malodorous components such as H2S and N3H in the purified gas online, serving as a direct basis for emission compliance.

[0035] A variable frequency circulating water pump 72 is installed on the main spray pipeline 73 between the circulating water tank 71 and the spray assembly 25, and is used to adjust the spray flow rate by frequency conversion. It also includes a backwash pipeline 75, a backwash nozzle 76, a backwash regulating valve 77, and a spray regulating valve 78. One end of the backwash pipeline 75 is connected to the outlet of the variable frequency circulating water pump 72, and the other end extends to the air inlet side of the packing layer 22 and connects to the backwash nozzle 76. A backwash valve 74 and a backwash regulating valve 77 are sequentially installed on the backwash pipeline 75 for backwashing. The nozzle 76 is positioned on the air inlet side of the packing layer 22 with the spray direction facing upwards in the opposite direction of the airflow. It is used to spray circulating water against the airflow direction onto the air inlet side of the packing layer 22 during rinsing and maintenance. The spray regulating valve 78 is located on the main spray pipeline 73 and is used to distribute the two flow rates in conjunction with the backwash regulating valve 77 during bidirectional rinsing. The nozzle of the spray assembly 25 is positioned above the air outlet side of the packing layer 22 with the spray direction facing downwards. It is used for normal spraying and moisturizing, and for rinsing the surface of the packing layer in the direction of the airflow during rinsing and maintenance. The alkali dosing pump 81 is connected to the alkali storage tank and is used to add alkali to neutralize sulfuric acid when the packing layer 22 becomes acidic. The nutrient solution dosing pump 82 is connected to the nutrient solution storage tank and is used to add nutrient solution to supplement microbial nutrition when the bacterial activity decreases. The input terminals of the PLC controller are connected to the pressure measuring points of the multi-section differential pressure monitoring component 3 and the sensor signals of the instrument system. The output terminals are connected to the circulating water pump 72, backwash valve 74, backwash regulating valve 77, spray regulating valve 78, alkali dosing pump 81, nutrient solution dosing pump 82, and centrifugal fan 5. The PLC controller has pre-installed modules for clogging location, metabolic activity heat index calculation, removal rate calculation, efficiency decline type decoupling discrimination, precise alkali dosing, over-limit early warning, and removal rate recovery assessment. These modules are used to realize functions such as clogging location, real-time calculation of metabolic activity heat index, real-time calculation of removal rate, decoupling discrimination between clogging and activity-type efficiency decline, precise alkali dosing, over-limit early warning, and removal rate recovery assessment. The touch screen of the PLC controller is located on the control cabinet panel for on-site operation and status display. The communication module is located inside the control cabinet for remote data transmission and monitoring via Ethernet interface. The outlet pipe of the alkali dosing pump 81 is connected to the spray assembly 25, and the outlet pipe of the nutrient solution dosing pump 82 is also connected to the spray assembly 25. The alkali solution and nutrient solution are sprayed onto the surface of the packing layer 22 through the nozzles of the spray assembly 25 and are evenly distributed in the packing layer 22 with the circulating water.

[0036] A metabolic activity heat index is constructed by comparing the detection values ​​of the packing layer temperature sensor 91 and the inlet air temperature sensor 94. This index utilizes the exothermic characteristics of the microbial degradation process to reflect the metabolic intensity of the microbial community in real time, enabling low-cost perception of changes in microbial activity without the need for an online gas concentration meter. The removal rate is calculated in real time by setting up inlet gas concentration sensor 95 and outlet gas concentration sensor 96, forming a dual-channel microbial activity monitoring system with the metabolic activity heat index. The metabolic activity heat index serves as a fallback in case of concentration meter failure or calibration issues. Through the decoupled judgment of multiple indicators including removal rate, pressure difference, and metabolic activity heat index, the system can accurately distinguish between blockage-type and activity-type efficiency declines and select the correct maintenance path. Precise alkali dosing is achieved by using time-limited quantitative feedforward of pH change rate and circulating liquid conductivity to differentiate the source of acidification. Early warning of exceeding standards is provided by monitoring the upward trend of outlet concentration, directly addressing the core requirement of instantaneous compliance with exhaust gas emission regulations.

[0037] In this embodiment, the arrangement of pressure measuring points in the multi-section differential pressure monitoring component 3 is described in detail. The number of pressure measuring points in the multi-section differential pressure monitoring component 3 is preferably four to six; in this embodiment, four pressure measuring points are used as a typical example. The pressure measuring points are arranged at equal or unequal intervals along the airflow direction, and two adjacent pressure measuring points constitute a differential pressure measurement section. In this embodiment, the four pressure measuring points are arranged at equal intervals along the airflow direction. The distance between the first pressure measuring point 31 and the second pressure measuring point 32 is equal to the distance between the second pressure measuring point 32 and the third pressure measuring point 33, and also equal to the distance between the third pressure measuring point 33 and the fourth pressure measuring point 34.

[0038] This arrangement ensures that the four pressure measuring points accurately reflect the local pressure conditions of the four cross-sections of the packing layer 22: the inlet side, the middle section, the outlet side, and the outlet assembly side, avoiding large measurement errors caused by measuring points being too close to the boundary. The flush-mounted diaphragm-type anti-clogging pressure transmitters at each pressure measuring point are fixed to the corresponding mounting holes on the side wall of the biological deodorization box 2 via flanges or threaded connections. The diameter of the mounting holes is slightly larger than the diameter of the transmitter diaphragm, and the transmitter diaphragm remains flush with the inner wall of the packing layer 22. An annular sealing ring is installed on the outer side of the pressure-sensing diaphragm to prevent leakage of packing particles. The industrial pressure transmitters at each pressure measuring point output a standard current signal, powered by DC.

[0039] Specifically, this embodiment also explains the selection and calibration principle of the packing layer moisture content sensor 92. The packing layer moisture content sensor 92 is a capacitive moisture content sensor, which includes a probe and a circuit unit. The probe is inserted into the middle of the packing layer 22. Utilizing the characteristic that the dielectric constant of the packing changes with the moisture content, the moisture content is converted into a capacitance signal, which is then converted into a standard current signal by the circuit unit and output to the PLC controller. Before use, the packing layer moisture content sensor 92 needs to be calibrated on-site. The calibration method is the drying and weighing method: During the commissioning phase of the biological deodorization system, samples are taken from multiple locations in the packing layer 22, and the capacitance corresponding to the sensor output signal is measured respectively; then, each packing sample is placed in a drying oven and dried to constant weight, and the dry weight is weighed. The mass moisture content is calculated according to the following formula: the mass moisture content is equal to the difference between the wet weight and the dry weight of the packing sample divided by the percentage of the dry weight; a calibration curve of capacitance signal and mass moisture content is established and stored in the non-volatile memory of the PLC controller. During on-site operation, the PLC controller obtains the real-time mass moisture content by looking up the calibration curve based on the capacitance signal output by the sensor. Under normal operating conditions, the mass moisture content of the packing layer 22 is maintained within the preset moisture content range. When the moisture content is lower than the preset drying threshold, it is determined to be in a dry state. Each threshold can be preset based on on-site calibration.

[0040] Therefore, by arranging four pressure measuring points along the height of the packing layer 22, each pressure measuring point can accurately reflect the local pressure conditions on the air inlet side, middle section, air outlet side, and air outlet component side of the packing layer 22. By forming a differential pressure measuring section by two adjacent pressure measuring points, three differential pressure measuring sections can be formed. Based on the differential pressure value and differential pressure change rate of each measuring section, the blockage location inside the packing layer 22 can be accurately determined. The third differential pressure measuring section is specifically used to identify blockage on the air outlet side, avoiding overlap with the blockage identification rules of the middle section. By using a flush diaphragm anti-clogging pressure transmitter, the long-term stable operation of the multi-section differential pressure monitoring component 3 can be ensured without the need for a backflushing device. By using a capacitive moisture content sensor in conjunction with the drying and weighing method for on-site calibration, the mass moisture content of the packing layer 22 can be accurately measured in real time, providing reliable data that conforms to the physical reality of the biofilter for active maintenance.

[0041] This embodiment describes the metabolic activity heat index and dual-channel microbial community activity monitoring. The pre-installed metabolic activity heat index calculation module inside the PLC controller is configured to calculate the metabolic activity heat index based on the difference between the detection values ​​of the packing layer temperature sensor 91 and the inlet air temperature sensor 94. The metabolic activity heat index is equal to the packing layer temperature minus the inlet air temperature, reflecting the exothermic intensity of the microbial degradation process. Since the microbial degradation of odorous pollutants is an exothermic reaction, when metabolism is vigorous, the temperature of the packing layer 22 is higher than the inlet air temperature, and the metabolic activity heat index is positive and relatively large. When the microbial community activity decreases (e.g., due to low temperature, poisoning, or nutrient imbalance), the exothermic effect weakens, and the metabolic activity heat index narrows or even approaches zero. Considering that the inlet air temperature of wastewater treatment plants in northern my country can drop to below freezing in winter and reach high temperatures in summer, with seasonal and diurnal temperature variations far exceeding the temperature rise caused by microbial metabolic exothermic reactions, this invention employs temperature correction for the metabolic activity thermal index to avoid interference from environmental temperature fluctuations in the determination of bacterial activity. The sliding average of the difference between the packing layer temperature and the inlet air temperature within a preset sliding window period (e.g., several consecutive days, which can be set to 24 hours to 7 days) is used as the criterion value for the metabolic activity thermal index, eliminating the interference of diurnal and seasonal temperature variations on the determination results. Furthermore, an effective temperature criterion is set: when the inlet air temperature is within a preset normal operating temperature range (e.g., 10℃ to 35℃, which can be adjusted on-site according to the characteristics of the bacterial species), the metabolic activity thermal index serves as an effective criterion for monitoring bacterial activity; when the inlet air temperature exceeds the preset normal operating temperature range, the metabolic activity thermal index is downgraded to a reference signal, and the type of efficiency decline is determined solely based on the removal rate. The narrowing of the metabolic activity thermal index is not used as an independent criterion for activity-related efficiency decline, thus avoiding misjudgment of bacterial activity loss in low-temperature seasons and masking of activity decline in high-temperature seasons. The criterion for narrowing the metabolic activity heat index is defined as follows: within a consecutive preset number of sampling periods (e.g., 3 consecutive sampling periods, each period is 60 seconds), the moving average of the metabolic activity heat index decreases by more than a preset narrowing ratio (e.g., more than 30%) compared to its most recent 24-hour average, or decreases by more than a preset temperature difference (e.g., more than 2°C) compared to the benchmark value calibrated during the commissioning phase. The above values ​​can be adjusted according to the working conditions and do not constitute a limitation of the present invention. The PLC controller is also configured to perform dual-channel microbial activity monitoring using the metabolic activity thermal index and the removal rate: when the metabolic activity thermal index is in an effective state, if the metabolic activity thermal index narrows and the removal rate decreases, it is determined that the microbial activity has decreased, and the dual-channel signals corroborate each other; when the metabolic activity thermal index is in an effective state, if the metabolic activity thermal index narrows and the detection value of the outlet gas concentration sensor 96 is normal, the metabolic activity thermal index is used as the basis for maintenance decisions and a nutrient supplementation or heat preservation prompt is output to intervene in advance to prevent further decline in activity; when the inlet gas concentration sensor 95 or the outlet gas concentration sensor 96 malfunctions or is being calibrated, the metabolic activity thermal index is used instead of the removal rate as the microbial activity monitoring signal to ensure continuous monitoring.Metabolic activity thermal indicators, as an indirect characterization of bacterial community activity, have a faster response speed than gas concentration detection, and can detect the trend of activity changes in advance before the removal rate has decreased significantly.

[0042] Therefore, by using the metabolic activity thermal index of the temperature difference between the packing layer and the inlet air, the exothermic characteristics of microorganisms can be used to reflect the metabolic intensity of the microbial community in real time. This allows for low-cost perception of changes in microbial community activity without the need for an online gas concentration meter, directly addressing the technical pain point of existing technologies that rely on expensive concentration meters and are often not installed in most projects, leading to a lack of awareness of decreased microbial community activity. By using the metabolic activity thermal index and removal rate to form a dual-channel microbial community activity monitoring system, the metabolic activity thermal index can be used as a fallback in case of concentration meter failure or calibration, ensuring continuous monitoring. Through early intervention when the metabolic activity thermal index narrows, the downward trend of microbial community activity can be detected and corrected in time before the outlet exceeds the standard.

[0043] This embodiment describes precise alkali dosing control. The pre-installed precise alkali dosing module within the PLC controller is configured to perform the following precise alkali dosing control: calculate the pH decrease rate based on the rate of change of the pH sensor 93; when the pH decrease rate exceeds a preset rate threshold, it is determined to be rapid acidification, and time-limited quantitative feedforward alkali dosing is performed. Specifically, there is a pipeline residence time when circulating water flows from the packing layer 22 through the drainage tank 24 to the pH sensor 93. The pH detection value reflects the state of the circulating water several minutes ago. If alkali is added according to the current pH value, there will inevitably be a lag. This invention uses pH decrease rate feedforward to increase the amount of alkali added in advance when the pH decreases rapidly, compensating for the detection lag and avoiding pH overshoot or fluctuation. However, if the rapid pH drop is caused by a high concentration of H2S shock rather than continuous acidification, continuous large-volume feedforward alkali addition will result in excessive alkali addition after the shock wave peak. Therefore, this invention sets time-limited quantitative constraints on feedforward alkali addition: the duration of feedforward alkali addition does not exceed the preset time limit (e.g., it can be set to 1 minute), and the cumulative addition does not exceed the preset dose limit (e.g., it can be set to a preset multiple of the normal steady-state addition). After reaching the preset time limit, feedforward alkali addition is paused and the pH drop rate is reassessed. If the pH is still dropping rapidly, time-limited quantitative feedforward is executed again. If the pH drop rate slows down, steady-state addition is switched to, thereby achieving a balance between rapid response and avoiding overdose. When the rate of pH decrease is within the normal range, the source of acidification is distinguished based on the detection value of the circulating liquid conductivity sensor 100: when conductivity increases and pH decreases, it is determined to be sulfur-type acidification (H2S oxidation produces sulfuric acid), and alkali solution is added to neutralize the sulfuric acid; when the increase in conductivity is less than the decrease in pH, it is determined to be nitrification-type acidification (N3H nitration consumes alkalinity to produce nitric acid), and alkali solution is added appropriately while bicarbonate is added simultaneously to replenish alkalinity. The differentiated response between sulfur-type and nitrification-type acidification avoids indiscriminate alkali addition: excessive addition of strong alkali in nitrification-type acidification will increase pH and inhibit the activity of nitrifying bacteria, while supplementing with bicarbonate neutralizes acidity and provides an inorganic carbon source for nitrifying bacteria.

[0044] Therefore, by using pH change rate to limit quantitative feedforward alkali dosing, it not only compensates for the lag in the circulating water detection pipeline, but also avoids excessive alkali dosing during shock acidification by setting upper limits for duration and dosage. By distinguishing between sulfur-type acidification and nitrification-type acidification by circulating liquid conductivity, a differentiated alkali dosing strategy is adopted to achieve precise alkali dosing, avoiding secondary disturbance to the microbial community caused by indiscriminate alkali dosing, and overcoming the shortcomings of existing technologies that only dos alkali according to pH threshold, resulting in inaccurate and delayed alkali dosing.

[0045] This embodiment describes the pre-emptive warning of exceeding emission standards and the assessment of removal rate recovery. The pre-installed pre-emptive warning module inside the PLC controller is configured as follows: based on the detection value of the outlet gas concentration sensor 96, the outlet concentration change rate is calculated. When the outlet concentration detection value shows an upward trend (positive change rate) within a continuous sampling period and the rate of increase exceeds a preset change rate threshold, but the outlet concentration detection value has not yet exceeded the emission standard, it is determined that there is a pre-emptive warning. The centrifugal fan 5 is reduced to prolong the residence time of the gas in the packing layer 22, and the output flow of the circulating water pump 72 is increased to enhance spray absorption, thus upgrading the emission control from a post-event alarm to a pre-emptive warning. If the outlet concentration is rapidly decreasing (negative change rate), even if its absolute value is large, it indicates that the system is recovering rather than a pre-emptive warning, and no warning is triggered, avoiding false alarms during the normal recovery process. Meanwhile, the circulating fluid conductivity sensor 100 is also used to monitor conductivity changes caused by slough-off products of aged biofilm in the circulating fluid. When the conductivity rises abnormally, it outputs a warning of impending slough-off, alerting operators that the aged biofilm may slough off over a large area, allowing for early, gentle maintenance to be performed and preventing sudden slough-off from causing instantaneous exceedances at the outlet. The PLC controller's internal preset removal rate recovery assessment module is configured to calculate the removal rate recovery rate after maintenance and simultaneously monitor the decline in removal rate: when the removal rate recovery rate is greater than a preset upper threshold and the removal rate is stable without decline, maintenance is deemed effective; when the removal rate recovery rate is between a preset lower threshold and a preset upper threshold, maintenance is deemed insufficient, and an increased maintenance intensity warning is output; when the removal rate recovery rate is less than a preset lower threshold, or when the removal rate recovers and then rapidly declines or fluctuates, maintenance is deemed excessive (too many functional bacteria have been flushed out), and a reduced maintenance intensity warning is output. Through this three-segment judgment, the direction of maintenance intensity adjustment can be clearly defined, avoiding the inability to distinguish between over-maintenance and under-maintenance due to the similarity of the recovery rate.

[0046] Therefore, by using early warning of the rising trend of the outlet concentration to prevent exceeding the standard, the system will only take action to reduce the air volume and strengthen the spray absorption when the outlet concentration shows an upward trend and the rate of increase exceeds the threshold, thus avoiding false alarms during the normal recovery process and directly addressing the core requirement of instantaneous compliance supervision of exhaust gas emissions; by monitoring the conductivity of the circulating liquid to detect the precursors of aging biofilm detachment, the system can prevent sudden detachment from causing instantaneous exceedances at the outlet; and by evaluating the maintenance effect through three-stage assessment of removal rate and recovery rate, the system can clearly distinguish between effective maintenance, insufficient maintenance, and excessive maintenance, thereby achieving adaptive optimization of maintenance intensity.

[0047] Example 2

[0048] This embodiment describes the overall process of the biological deodorization treatment method. The method provided in this embodiment is applied to the biological deodorization treatment system of the aforementioned embodiment and includes the following steps: S10: Along the airflow direction, pressure signals are collected at each pressure measuring point in the packing layer 22 to calculate the differential pressure value of each differential pressure measuring section, and the detection values ​​of the inlet gas concentration sensor 95, outlet gas concentration sensor 96, packing layer temperature sensor 91, inlet air temperature sensor 94, pH sensor 93 and circulating liquid conductivity sensor 100 are collected simultaneously.

[0049] S20, locate the blockage position of the packing layer 22 according to the pressure difference value and pressure difference change rate of each pressure difference measurement section, and calculate the metabolic activity heat index and removal rate; wherein the metabolic activity heat index is the sliding average value of the difference between the packing layer temperature and the inlet air temperature within the preset sliding window time as the criterion value, and the removal rate is equal to one minus the ratio of the outlet concentration to the inlet concentration and then multiplied by 100%.

[0050] S30 combines removal rate, pressure difference, and metabolic activity heat index to determine the type of efficiency decline.

[0051] S40, when the efficiency decline is determined to be due to blockage, the circulating water pump 72 and the backwash valve 74 are linked to perform flushing maintenance. When the efficiency decline is determined to be due to activation, the corresponding activation maintenance is performed in conjunction with the detection values ​​of the packing layer temperature sensor 91, the packing layer moisture content sensor 92, the pH sensor 93 and the circulating liquid conductivity sensor 100.

[0052] S50, after the maintenance action is completed, the maintenance effect is evaluated based on the removal rate recovery and closed-loop verification is performed. At the same time, an early warning of exceeding the standard is issued when the detection value of the outlet gas concentration sensor 96 shows an upward trend and the rate of change exceeds the threshold.

[0053] Therefore, through the coordinated execution of S10-S50, the biological deodorization system can achieve a complete and meticulous process of microbial health maintenance, from data acquisition, blockage location, calculation of metabolic activity thermal indicators and removal rate, decoupling and identification of efficiency decline types, differentiated maintenance, precise alkali dosing, early warning of exceeding standards, to assessment of removal rate recovery. By combining and decoupling multiple indicators, it can accurately distinguish between blockage-type and activity-type efficiency decline. By using metabolic activity thermal indicators, it can achieve low-cost perception of microbial activity without concentration meters. By using precise alkali dosing and early warning of exceeding standards, it can directly address emission compliance regulatory requirements.

[0054] In this embodiment, the execution process of bidirectional flushing in the flushing maintenance step S40 is described. When S30 determines that the efficiency decrease is due to blockage, the PLC controller outputs a flushing maintenance command, and at the same time opens the backwash valve 74 and increases the output flow of the circulating water pump 72. The circulating water is divided into two paths after being pressurized by the circulating water pump 72 from the circulating water tank 71: one path enters the spray assembly 25 through the spray main pipeline 73 and the spray regulating valve 78, and sprays downward in the direction of airflow from above the air outlet side of the packing layer 22, flushing the surface of the air outlet side of the packing layer 22 and the middle packing; the other path enters the backwash nozzle 76 through the backwash pipeline 75, the backwash valve 74 and the backwash regulating valve 77, and sprays upward against the direction of airflow from the air inlet side of the packing layer 22, directly impacting the dust particle layer deposited on the air inlet side, peeling it off from the surface of the packing and lifting it loose. Since the two branches are connected in parallel, the flow distribution depends on the resistance characteristics of each branch. To avoid insufficient flow in one branch due to flow imbalance, the PLC controller synchronously adjusts the opening of the backwash regulating valve 77 and the spray regulating valve 78 according to the preset flow distribution ratio during flushing and maintenance. This ensures that the flow ratio of the two branches meets the respective flow requirements of the backwash nozzle 76 for counter-current spraying and the spray assembly 25 for co-current spraying. The equivalent lengths of the backwash pipeline 75 and the main spray pipeline 73 are matched by hydraulic calculations to ensure that the flow distribution ratio of the two branches meets the respective flow requirements of flushing and spraying under the rated head of the circulating water pump 72. The two water flows meet and collide inside the packing layer 22, forming a bi-directional turbulent water flow. This causes the dust particles, aged biofilm, and caking material attached to the pores of the packing layer 22 to peel off from the surface of the packing under the action of the bi-directional water flow and be discharged downwards through the drainage pool 24 out of the tank 21. During flushing and maintenance, the PLC controller monitors the pressure difference changes of each pressure difference measurement section in real time based on the multi-section differential pressure monitoring component 3. When the pressure difference ratio of the first differential pressure measurement section corresponding to the air inlet side drops to the preset recovery threshold, it is determined that the dust blockage has been basically cleared. The backwash valve 74 is closed and the normal spray flow of the circulating water pump 72 is restored, and the flushing and maintenance ends. The spray pressure of the backwash nozzle 76 can be adjusted by the opening of the backwash valve 74 or the output frequency of the circulating water pump 72. The flushing intensity is adaptively adjusted according to the degree of blockage to avoid excessive stripping of functional bacteria by excessive flushing. The flushing and maintenance is completed online while the centrifugal fan 5 is running normally, without the need to stop the machine. Through bidirectional flushing, the dust deposits on the air inlet side (the main cause of packing blockage) are directly dispersed by the countercurrent spray, and the caking and peeling of the middle section biofilm on the air outlet side are washed away by the co-current. The blockage of the entire packing layer is effectively removed, overcoming the technical defect of the existing technology that only flushes from the top in the co-current direction, resulting in incomplete removal of blockage on the air inlet side.

[0055] In this embodiment, the detailed explanation of the blockage location locating step S20 is provided. S20 further includes: calculating the proportion of the pressure difference of each pressure difference measurement segment to the total pressure difference between the first and last pressure measurement points along the airflow direction, to obtain the pressure difference proportion of each pressure difference measurement segment; wherein the first and last pressure measurement points along the airflow direction are the first pressure measurement point 31 and the fourth pressure measurement point 34, and the total pressure difference is the pressure difference between the first pressure measurement point 31 and the fourth pressure measurement point 34, that is, the sum of the pressure differences of the first pressure difference measurement segment, the second pressure difference measurement segment, and the third pressure difference measurement segment. When the pressure difference proportion of the first pressure difference measurement segment is greater than the first proportion threshold and the duration is greater than the first duration threshold, it is determined that a blockage has occurred on the air inlet side of the packing layer 22; a typical working condition is that the odorous gas transported from the sludge thickening tank or sludge dewatering room carries dust particles, and the pre-washing section 4 fails to completely remove the dust, and the dust particles are deposited on the air inlet side of the packing layer 22. When the differential pressure ratio in the second differential pressure measurement section is greater than the second ratio threshold and the duration is greater than the second duration threshold, blockage is determined to have occurred in the middle section of the packing layer 22. A typical scenario is that after long-term operation, microorganisms in the middle section of the packing layer 22 excessively multiply and accumulate at suitable temperatures, forming a thick biofilm. When the differential pressure ratio in the third differential pressure measurement section is greater than the third ratio threshold and the duration is greater than the third duration threshold, blockage is determined to have occurred on the outlet side of the packing layer 22. A typical scenario is that the overall moisture content of the packing layer 22 is too high, and local water accumulation leads to an abnormally high airflow resistance on the outlet side. Since the determination of outlet-side blockage is entirely based on the dedicated third differential pressure measurement section, which is independent of the second differential pressure measurement section used for middle section blockage determination, it can reliably distinguish between outlet-side blockage and middle section blockage. The ratio thresholds and duration thresholds can be preset based on on-site calibration and do not constitute a limitation of the present invention.

[0056] Therefore, by defining the total pressure difference as the pressure difference between the first and last pressure measuring points along the airflow direction, the definition of the total pressure difference remains valid even when there are four or more pressure measuring points. The sum of the pressure difference percentages of each pressure difference measuring segment is always equal to one, ensuring the accuracy of the pressure difference percentage calculation. By setting a dedicated third pressure difference measuring segment to identify blockage on the outlet side, the blockage location of the packing layer 22 can be accurately distinguished into three typical locations: the inlet side, the middle section, and the outlet side, avoiding misjudgment caused by overlapping discrimination rules.

[0057] In this embodiment, the details of the efficiency decline type discrimination step S30 are explained. S30 further includes: comparing the removal rate, the differential pressure value of each differential pressure measurement segment, and the metabolic activity heat index; when the removal rate is lower than the preset removal rate threshold and the differential pressure value or differential pressure ratio of any differential pressure measurement segment exceeds the corresponding threshold, it is judged as a blockage-type efficiency decline; when the removal rate is lower than the preset removal rate threshold and the differential pressure value of each differential pressure measurement segment does not exceed the corresponding threshold, or the metabolic activity heat index is in an effective state and narrows, it is judged as an activity-type efficiency decline. The temperature detection value of the packing layer temperature sensor 91, the moisture content detection value of the packing layer moisture content sensor 92, the pH detection value of the pH sensor 93, and the conductivity detection value of the circulating liquid conductivity sensor 100 are input into the preset activity maintenance discrimination rules, and at least one activity maintenance type is output from low temperature and low activity, shock load, packing drying, and packing layer acidification. The specific judgment logic is as follows: When the removal rate decreases and the pressure difference increases, it indicates that there is physical blockage in the packing layer 22, leading to airflow short-circuiting or increased resistance, and is judged as a blockage-type efficiency decrease; when the removal rate decreases but the pressure difference is normal, it indicates that the airflow channel is unobstructed but the bacterial degradation capacity is insufficient, and is judged as an active type efficiency decrease; when the removal rate has not decreased significantly but the metabolic activity heat index is in an effective state and narrows, it is also judged as an active type efficiency decrease, achieving early intervention in the early stage of activity decrease. When the inlet air temperature exceeds the preset normal operating temperature range, causing the metabolic activity heat index to be in a degraded state, the narrowing of the metabolic activity heat index is not used as an independent criterion for active type efficiency decrease. Only the low removal rate and normal pressure difference are used as the basis for judging activity, avoiding misjudgment caused by environmental temperature fluctuations in winter low temperature or summer high temperature season. After determining that the efficiency of the active type has decreased, the active curing type is further subdivided based on the combination of temperature, moisture content, pH, and conductivity: low temperature and low activity is output when the temperature is below the low temperature threshold and the moisture content is normal; shock load is output when the inlet gas concentration detection value and change rate exceed the impact threshold; packing drying is output when the moisture content is below the drying threshold; and packing layer acidification is output when the pH is below the acidification threshold and the conductivity increases. If multiple active curing conditions are met simultaneously, the active curing type is output according to the preset priority.

[0058] Therefore, by decoupling and judging multiple indicators such as removal rate, pressure difference, and metabolic activity heat index, the efficiency decline can be accurately classified into two causes: blockage and activity, providing a basis for selecting the correct maintenance path. By using the metabolic activity heat index as a supplementary signal for activity discrimination, the decline in bacterial activity can be detected in advance when the pressure difference is normal, making up for the pressure difference blind spot. By further subdividing the activity-related efficiency decline through the activity maintenance discrimination rule, the corresponding activity maintenance type can be accurately output.

[0059] This embodiment details the precise alkali dosing steps. The method in this embodiment also includes a precise alkali dosing step: calculating the pH decrease rate based on the rate of change of the pH sensor 93; when the pH decrease rate exceeds a preset rate threshold, it is determined to be rapid acidification, and time-limited quantitative feedforward alkali dosing is performed, i.e., the dosage of the alkali solution dosing pump 81 is increased feedforward based on the pH decrease rate, and the duration of alkali dosing does not exceed a preset time limit and the cumulative dosage does not exceed a preset dose limit. After reaching the preset time limit, feedforward alkali dosing is paused and reassessed to avoid excessive alkali dosing due to continuous large-scale alkali dosing after the high-concentration H2S shock wave peak; when the pH decrease rate is within the normal range, the source of acidification is distinguished based on the detection value of the circulating liquid conductivity sensor 100: when conductivity increases and pH decreases, it is determined to be sulfur-type acidification, and alkali solution is added to neutralize sulfuric acid; when the increase in conductivity is less than the decrease in pH, it is determined to be nitration-type acidification, and alkali solution is added appropriately while simultaneously adding bicarbonate to supplement alkalinity. Specifically, the pH detection of circulating water suffers from pipeline lag. By feedforwarding the rate of pH decrease, the amount of alkali added can be increased in advance before the pH drops to the threshold, thus avoiding pH overshoot. Time-limited and quantitative constraints can prevent excessive alkali addition during shock acidification. By distinguishing the source of acidification by conductivity, the inhibition of nitrifying bacteria by indiscriminate alkali addition can be avoided, thus achieving precise alkali addition.

[0060] Therefore, by using pH change rate feedforward to compensate for detection lag, and by using the conductivity of the circulating liquid to distinguish between sulfur-type acidification and nitrification-type acidification and to differentiate alkali dosage, precise alkali dosage can be achieved, avoiding secondary disturbance to the microbial community caused by alkali dosing oscillation and excessive alkali dosing.

[0061] This embodiment details the steps for early warning of exceeding emission standards and assessment of removal rate recovery. The method in this embodiment also includes the steps for early warning of exceeding emission standards and assessment of removal rate recovery: The outlet concentration change rate is calculated based on the detection value of the outlet gas concentration sensor 96. When the outlet concentration detection value shows an upward trend (positive change rate) within a continuous sampling period and the rate of increase exceeds a preset change rate threshold, but the outlet concentration detection value has not yet exceeded the emission standard, an early warning of exceeding emission standards is determined. This is followed by a reduction in the speed of the centrifugal fan 5 to extend the gas residence time in the packing layer 22 and an increase in the output flow of the circulating water pump 72 to enhance spray absorption. When the outlet concentration drops rapidly, it is determined to be in a recovery state, and no warning is triggered. After the maintenance action is completed, the removal rate recovery rate is calculated, and the decline in the removal rate is monitored simultaneously: When the removal rate recovery rate is greater than a preset upper threshold and the removal rate is stable without decline, the maintenance is deemed effective; when the removal rate recovery rate is between a preset lower threshold and a preset upper threshold, the maintenance is deemed insufficient, and an enhanced maintenance intensity prompt is output; when the removal rate recovery rate is less than a preset lower threshold, or the removal rate declines rapidly or fluctuates after recovery, the maintenance is deemed excessive, and a reduced maintenance intensity prompt is output. The system monitors the signs of aging biofilm detachment based on the detection value of the circulating fluid conductivity sensor 100, and outputs a warning of detachment when the conductivity increases abnormally.

[0062] Therefore, by using early warning of the rising trend of the outlet concentration to prevent exceeding the standard, the system can proactively reduce the air volume and strengthen spray absorption when the outlet concentration has not yet exceeded the standard but the rising trend is abnormal, directly addressing the core requirement of instantaneous compliance supervision of exhaust gas emissions; by evaluating the maintenance effect through three-stage assessment of removal rate and recovery rate, the system can clearly distinguish between effective maintenance, insufficient maintenance, and excessive maintenance, and output corresponding adjustment directions to achieve adaptive optimization of maintenance intensity; and by monitoring the conductivity of the circulating liquid to detect the precursors of aging biofilm detachment, the system can avoid sudden detachment that could lead to instantaneous exceeding of the standard at the outlet, achieving comprehensive and meticulous maintenance of the microbial community health of the biological deodorization system.

[0063] In this embodiment, the engineering implementation details of monitoring the metabolic activity heat index are further explained. Considering the temperature differences at different locations in the biological deodorization box (low temperature on the inlet side, high temperature on the outlet side, and abnormal temperature at local blockage points), the packing layer temperature sensor 91 can be set with multiple temperature measurement points along the airflow direction and the weighted average value can be taken, or it can be set in the middle section of the packing layer 22 near the center, which is the main area for airflow distribution and microbial metabolic activity, and its temperature change can represent the overall metabolic heat release trend of the packing layer 22. The inlet temperature sensor 94 is set on the straight section of the inlet duct upstream of the inlet air distribution assembly 23, and the difference between the two detected values ​​is the metabolic activity heat index. The PLC controller continuously collects the detected values ​​of the packing layer temperature sensor 91 and the inlet temperature sensor 94 at a preset sampling period, calculates the real-time value of the metabolic activity heat index and its sliding average value, and uses the sliding average value within a preset sliding window period (e.g., 24 hours to 7 days) to eliminate the influence of diurnal and seasonal fluctuations in inlet temperature; at the same time, it stores the historical curve of the metabolic activity heat index, allowing operators to view the long-term trend of microbial activity through a touch screen. When the moving average of the metabolic activity thermal index continuously narrows relative to the baseline value and the narrowing exceeds the preset narrowing threshold (e.g., a decrease of more than 30% compared to the average value of the most recent 24 hours within three consecutive sampling periods, or a decrease of more than 2°C compared to the calibration benchmark value during the commissioning phase; each threshold can be adjusted according to the operating conditions), the PLC controller determines that the bacterial activity has decreased, and outputs a nutrient supplementation or heat preservation prompt, and simultaneously displays the warning information on the touch screen and the remote monitoring center. The metabolic activity thermal index and the removal rate corroborate each other: when both decrease simultaneously, it is determined that the bacterial activity has decreased; when the metabolic activity thermal index decreases but the removal rate remains normal, it is determined that the bacterial activity is in the early stage of decline, and preventive maintenance is performed in advance to avoid further decline in activity leading to exceeding the outlet standard.

[0064] In this embodiment, the selection of the circulating liquid conductivity sensor 100 and the engineering implementation for distinguishing the source of acidification are further explained. The circulating liquid conductivity sensor 100 is preferably an electromagnetic or electrode-type conductivity meter, installed on the circulating liquid return pipeline 79 between the drain tank 24 and the circulating water tank 71, to detect the circulating liquid conductivity to reflect the ion concentration. Since both sulfuric acid produced by H2S oxidation (sulfur-type acidification) and nitric acid produced by N3H nitration consuming alkalinity (nitration-type acidification) increase the ion concentration and conductivity of the circulating liquid, the source cannot be directly distinguished by conductivity alone. Therefore, this invention combines conductivity changes with pH changes for analysis: during sulfur-type acidification, sulfuric acid is a strong acid, resulting in a significant decrease in pH and a significant increase in conductivity; during nitration-type acidification, the amount of nitric acid generated is relatively limited, and some alkalinity is consumed, resulting in a relatively smaller decrease in pH and a relatively smaller increase in conductivity. By pre-calibrating the correlation curve between conductivity changes and pH changes on-site, the PLC controller can distinguish between sulfur-type acidification and nitrification-type acidification based on the relative relationship between the current conductivity change rate and pH change rate, and execute differentiated alkali addition strategies: for sulfur-type acidification, alkali solution is added as the main method, while for nitrification-type acidification, bicarbonate is added as the main method to supplement alkalinity, with alkali solution as a supplement, taking into account both neutralizing acidity and supplementing inorganic carbon source for nitrifying bacteria.

[0065] This embodiment further illustrates the integrated operation of the system in typical application scenarios. Taking the odor control scenario of the sludge dewatering room in a municipal wastewater treatment plant as an example, the odorous gas enters the biological deodorization treatment system after being collected in a closed system: Under normal operating conditions, the PLC controller monitors the activity of the bacterial community in real time based on the metabolic activity thermal index and removal rate, and performs activity-airflow matching control to maintain the outlet compliance; when a high concentration of H2S occasionally occurs in the sludge dewatering room, the detection value and change rate of the inlet gas concentration sensor 95 exceed the impact threshold. The PLC controller determines the impact load and links to reduce the speed of the centrifugal fan 5 and increase the output flow of the circulating water pump 72 to form a buffer response; during the impact, the pH sensor 93 detects... As the pH rapidly decreases, the PLC controller executes timed and quantitative feedforward alkali dosing based on the pH change rate. This involves increasing the dosage of alkali solution by the feedforward pump 81 while ensuring the dosing duration does not exceed a preset upper limit. The system confirms sulfur-type acidification based on the circulating liquid conductivity sensor 100, precisely neutralizing the sulfuric acid with alkali. Feedforward alkali dosing automatically pauses after the shock wave peak to prevent overdosing. After the shock load is released, the airflow is gradually restored, and nutrient solution is added to execute a recovery response. Throughout the process, if the outlet gas concentration sensor 96 shows an upward trend and the rate of change exceeds a threshold, an early warning of exceeding the standard is triggered, ensuring instantaneous compliance at the outlet. This system is highly compatible with existing biological deodorization projects. It only requires adding a circulating liquid conductivity sensor 100, a backwash regulating valve 77, and a spray regulating valve 78 to the existing system, along with upgrading the PLC controller's control program. The engineering modifications are minimal, and the implementation cost is low, making it particularly suitable for the intelligent upgrade of existing biological deodorization systems.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A biological deodorization treatment system, comprising a biological deodorization chamber (2), a centrifugal fan (5), and a chimney (6), wherein the biological deodorization chamber (2) comprises a chamber body (21) and a packing layer (22), a spray assembly (25), and a drainage tank (24) disposed within the chamber body (21), characterized in that: It also includes a multi-section differential pressure monitoring component (3) arranged along the airflow direction in the packing layer (22), which includes at least four pressure measuring points, and two adjacent measuring points constitute a differential pressure measuring section; The instrumentation system is used to detect the packing layer temperature, inlet air temperature, inlet gas concentration, outlet gas concentration, circulating liquid pH value, circulating liquid conductivity, and packing layer moisture content. The actuators include a circulating water pump (72), a backwash valve (74), an alkaline dosing pump (81), a nutrient solution dosing pump (82), and a circulating liquid return line (79) on the main spray pipeline (73); the PLC controller is connected to the multi-section differential pressure monitoring component (3) and the instrument system signal, and is connected to the actuators and the centrifugal fan (5) for control. The PLC controller is configured to calculate the metabolic activity heat index based on the difference between the packing layer temperature and the inlet air temperature, calculate the removal rate based on the inlet and outlet gas concentrations, and locate the blockage position based on the pressure difference value and change rate of each pressure difference measurement section. When the removal rate decreases and the pressure difference increases, it is determined to be a blockage type and flushing maintenance is initiated. When the removal rate decreases and the pressure difference is normal, it is determined to be an active type and maintenance is initiated. When the metabolic activity heat index is in an effective state and narrows, it is also determined to be an active type and maintenance is initiated. The alkali dosage is determined based on the circulating liquid pH value and change rate feedforward and combined with conductivity to distinguish the source of acidification. The feedforward alkali dosage limits the duration and dosage. When the outlet concentration shows an upward trend and the change rate exceeds the threshold, an early warning of exceeding the standard is issued, and the maintenance effect is evaluated and closed-loop verification is performed based on the removal rate recovery.

2. The biological deodorization system according to claim 1, characterized in that, The instrument system includes a packing layer moisture content sensor (92), a packing layer temperature sensor (91), an inlet air temperature sensor (94), a pH sensor (93), a circulating liquid conductivity sensor (100), an inlet gas concentration sensor (95), and an outlet gas concentration sensor (96). The packing layer moisture content sensor (92) and the packing layer temperature sensor (91) are located inside the packing layer (22), the inlet air temperature sensor (94) is located on the inlet air duct, the pH sensor (93) and the circulating liquid conductivity sensor (100) are located on the circulating liquid return line (79), the inlet gas concentration sensor (95) is located on the inlet air duct, and the outlet gas concentration sensor (96) is located on the purified gas line.

3. The biological deodorization system according to claim 1, characterized in that, The multi-section differential pressure monitoring component (3) has four to six pressure measuring points, and each pressure measuring point is arranged at equal or unequal intervals along the airflow direction; the differential pressure measuring section includes a first differential pressure measuring section located between the first pressure measuring point (31) and the second pressure measuring point (32), a second differential pressure measuring section located between the second pressure measuring point (32) and the third pressure measuring point (33), and a third differential pressure measuring section located between the third pressure measuring point (33) and the fourth pressure measuring point (34).

4. The biological deodorization treatment system according to claim 1, characterized in that, It also includes a backwash pipeline (75) and a backwash nozzle (76). One end of the backwash pipeline (75) is connected to the outlet of the circulating water pump (72), and the other end extends to the air inlet side of the packing layer (22) and is connected to the backwash nozzle (76). The backwash valve (74) is installed on the backwash pipeline (75), and the spray direction of the backwash nozzle (76) is set upward along the reverse airflow direction. The nozzle of the spray assembly (25) is arranged above the air outlet side of the packing layer (22) and the spray direction is downward. It also includes a backwash regulating valve (77) installed on the backwash pipeline (75) and a spray regulating valve (78) installed on the main spray pipeline (73). When the backwash valve (74) is opened, the PLC controller adjusts the opening degree of the backwash regulating valve (77) and the spray regulating valve (78) to distribute the two flow rates, so that the circulating water is sprayed in the reverse airflow direction through the backwash nozzle (76) and sprayed in the airflow direction through the spray assembly (25) to form bidirectional flushing.

5. A biological deodorization treatment system according to claim 2, characterized in that, The PLC controller is also configured to perform temperature correction and effectiveness criteria for metabolic activity thermal index: the sliding average value of the difference between the packing layer temperature and the intake air temperature within a preset sliding window period is used as the criterion value for metabolic activity thermal index, eliminating the interference of diurnal fluctuations in intake air temperature. When the inlet air temperature is within the preset normal operating temperature range, the metabolic activity thermal index serves as an effective criterion for monitoring bacterial activity. When the inlet air temperature exceeds the preset normal operating temperature range, the metabolic activity thermal index is downgraded to a reference signal. The efficiency decline type is determined solely based on the removal rate. The narrowing of the metabolic activity thermal index is not used as an independent criterion for the decline in activity-type efficiency. The metabolic activity thermal index and the removal rate form a dual-channel bacterial activity monitoring system: when the metabolic activity thermal index is in an effective state, the bacterial activity decline is determined when the metabolic activity thermal index narrows and the removal rate decreases. When the metabolic activity thermal index is in an effective state, the bacterial activity decline is determined when the metabolic activity thermal index narrows and the detection value of the outlet gas concentration sensor (96) is normal. The metabolic activity thermal index is used as the basis for maintenance decision-making and a nutrient supplementation or heat preservation prompt is output. When the inlet gas concentration sensor (95) or outlet gas concentration sensor (96) malfunctions or is not calibrated, the metabolic activity thermal index is used instead of the removal rate as the signal for monitoring bacterial community activity.

6. A biological deodorization treatment method, applied to a biological deodorization treatment system as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S10: Collect the differential pressure values ​​of each differential pressure measurement section, as well as the detection values ​​of packing layer temperature, inlet air temperature, inlet gas concentration, outlet gas concentration, circulating liquid pH value, circulating liquid conductivity, and packing layer moisture content. S20: Locate the blockage location of the packing layer (22) based on the pressure difference value and pressure difference change rate of each pressure difference measurement section, and calculate the metabolic activity heat index and removal rate; S30: Combine removal rate, pressure difference and metabolic activity heat index to determine the type of efficiency decline; S40: When the efficiency decline is determined to be due to blockage, the circulating water pump (72) and backwash valve (74) are activated to perform flushing maintenance; when the efficiency decline is determined to be due to activation, activation maintenance is activated. S50: After the maintenance is completed, the maintenance effect is evaluated based on the removal rate recovery and a closed-loop review is conducted. At the same time, an early warning of exceeding the standard is issued when the outlet concentration shows an upward trend and the change rate exceeds the threshold.

7. The biological deodorization treatment method according to claim 6, characterized in that, S10 also includes: collecting pressure signals at each pressure measuring point in the packing layer (22) along the airflow direction, and simultaneously collecting the detection values ​​of inlet gas concentration, outlet gas concentration, packing layer temperature, inlet air temperature, circulating liquid pH value and circulating liquid conductivity detected by the instrument system; using the sliding average value of the difference between the packing layer temperature and the inlet air temperature within the preset sliding window time as the criterion value of the metabolic activity heat index, and the removal rate is equal to one minus the ratio of the outlet concentration to the inlet concentration.

8. The biological deodorization treatment method according to claim 6, characterized in that, S20 further includes: calculating the ratio of the pressure difference of each pressure difference measurement segment to the total pressure difference between the first and last pressure measurement points along the airflow direction, and obtaining the pressure difference ratio of each pressure difference measurement segment; when the pressure difference ratio of the first pressure difference measurement segment is greater than the first ratio threshold and the duration is greater than the first duration threshold, it is determined that the air inlet side of the packing layer (22) is blocked; when the pressure difference ratio of the second pressure difference measurement segment is greater than the second ratio threshold and the duration is greater than the second duration threshold, it is determined that the middle section of the packing layer (22) is blocked; when the pressure difference ratio of the third pressure difference measurement segment is greater than the third ratio threshold and the duration is greater than the third duration threshold, it is determined that the air outlet side of the packing layer (22) is blocked.

9. The biological deodorization treatment method according to claim 6, characterized in that, S30 also includes: comparing the removal rate, the differential pressure value of each differential pressure measurement segment, and the metabolic activity heat index; when the removal rate is lower than the preset removal rate threshold and the differential pressure value or differential pressure ratio of any differential pressure measurement segment exceeds the corresponding threshold, it is judged as a blockage-type efficiency decrease; when the removal rate is lower than the preset removal rate threshold and the differential pressure value of each differential pressure measurement segment does not exceed the corresponding threshold, or the metabolic activity heat index is in an effective state and narrows, it is judged as an activity-type efficiency decrease; and inputting the packing layer temperature value, packing layer moisture content value, circulating liquid pH value, and circulating liquid conductivity value detected by the instrument system into the preset activity maintenance discrimination rules, and outputting at least one activity maintenance type among low temperature and low activity, shock load, packing drying, and packing layer acidification.

10. A biological deodorization treatment method according to claim 6, characterized in that, It also includes precise alkali dosing, early warning of exceeding the standard and evaluation of removal rate recovery: the pH drop rate is calculated based on the rate of change of circulating liquid pH detected by the instrument system. When the pH drop rate exceeds the preset rate threshold, it is determined to be rapid acidification. Time-limited quantitative feedforward alkali dosing is performed, that is, the amount of alkali dosing pump (81) is increased according to the pH drop rate and the duration of alkali dosing does not exceed the preset time limit and the cumulative amount of alkali dosing does not exceed the preset dose limit. After reaching the preset time limit, the feedforward alkali dosing is suspended and re-evaluated. When the pH decrease rate is within the normal range, the acidification source is identified based on the circulating fluid conductivity detected by the instrument system. When the conductivity increases and the pH decreases, it is determined to be sulfur-type acidification, and alkali solution is added to neutralize the sulfuric acid. When the increase in conductivity is less than the decrease in pH, it is determined to be nitration-type acidification, and alkali solution is added appropriately, along with bicarbonate to supplement alkalinity. The outlet concentration change rate is calculated based on the outlet gas concentration detected by the instrument system. When the outlet concentration detection value shows an upward trend within the continuous sampling period and the rate of increase exceeds the preset change rate threshold, but the outlet concentration detection value has not yet exceeded the emission standard, it is determined that there is a precursor to exceeding the standard, and the emission level is reduced accordingly. The rotational speed of the blower (5) extends the residence time of the gas in the packing layer (22) and increases the output flow of the circulating water pump (72) to enhance spray absorption. After the maintenance action is completed, the removal rate recovery rate is calculated and the removal rate decline is monitored simultaneously. When the removal rate recovery rate is greater than the preset upper threshold and the removal rate is stable without decline, the maintenance is deemed effective. When the removal rate recovery rate is between the preset lower threshold and the preset upper threshold, the maintenance is deemed insufficient and an enhanced maintenance intensity prompt is output. When the removal rate recovery rate is less than the preset lower threshold, or the removal rate declines rapidly or fluctuates after recovery, the maintenance is deemed excessive and a reduced maintenance intensity prompt is output.

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