Intelligent high-efficiency composite biological filter bed wastewater recycling process and system

Abstract

The invention belongs to the technical field of wastewater recycling, and mainly relates to an intelligent efficient composite biological filter bed wastewater recycling process and system.The process comprises the following steps that firstly, waste gas generated by a waste gas source is collected and enters a bipolar efficient cyclone hybrid spray tower under the action of traction force of a draught fan, and particulate matter is rapidly intercepted and filtered; wherein the environmental conditions of the waste gas treated by the spray tower are controlled, the waste gas is introduced into the secondary filler spray absorption tower to wash and absorb soluble components, and the waste gas is pretreated; the pretreated waste gas is guided into a biological filter bed uniform air flow mixing area, after environmental conditions are adjusted, the waste gas is uniformly guided into a composite biological filler area, and active microorganisms degrade organic matter in the waste gas through biological enzyme and convert the organic matter into inorganic matter to be stored in a circulating water pool; the inorganic matters are circulating water and carbon dioxide, and if the electric conductivity of the circulating water exceeds a certain value, the circulating water is diluted; and finally, the circulating water is stored in a circulating water tank after being subjected to secondary and tertiary purification through the deep oxidation absorption tower and the demisting absorber, so that the defects in the prior art are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater recovery, and specifically relates to an intelligent and efficient composite biological filter bed wastewater reuse process and system. Background Art

[0002] Volatile organic compounds (VOCs) are pollutants that are widely present in industrial production and are usually discharged in industrial waste gas, which poses great harm to the environment and human health. Although traditional treatment methods such as activated carbon adsorption and catalytic combustion can partially remove VOCs, they have disadvantages such as high treatment costs, easy to produce secondary pollution, and poor operating stability. In contrast, biofilter bed technology is widely used in VOCs waste gas treatment in the industrial field because of its advantages such as high efficiency in removing organic waste gas pollutants, low investment and operating costs, and environmental friendliness.

[0003] In the specific implementation process, the biofilter bed uses the active microorganisms attached to the surface of the composite filler, VOCs in the waste gas as a carbon source and energy source, and uses the highly efficient catalytic enzymes secreted by its own metabolism in an aerobic environment to degrade the organic pollutants in the waste gas into harmless water and simple inorganic substances such as carbon dioxide, thereby achieving pollution control. Although the existing biofilter bed technology has the above advantages, in actual applications, the circulating water formed after the waste gas is treated by the biofilter bed often accumulates dissolved salts in the water during the long-term recycling process, resulting in increased conductivity. When the conductivity exceeds 10,000 μS / cm, it will significantly inhibit the metabolic activity of microorganisms, causing the system treatment efficiency to drop by more than 30%. Long-term circulation of wastewater can easily lead to sludge concentrations exceeding 5g / L, and sludge accumulation will block the filler pores in the biofilter bed and reduce the oxygen mass transfer efficiency.

[0004] Based on this, it is urgent to improve the existing biological filter bed wastewater reuse process and system to solve the many technical defects in the existing technology. Summary of the invention

[0005] One of the purposes of the present invention is to provide an intelligent and efficient composite biofilter wastewater reuse process that can solve the technical defect of increasingly low system treatment efficiency in view of the shortcomings of the prior art.

[0006] In order to achieve the above-mentioned invention objectives, this application implements the following technical solutions:

[0007] An intelligent and efficient composite biofilter wastewater reuse process comprises the following steps:

[0008] S101. The VOCs waste gas generated by the waste gas generation source is collected through the pipe network and enters a bipolar high-efficiency cyclone hybrid spray tower along the tangent direction under the traction force of the fan. The VOCs waste gas is quickly intercepted and filtered for particulate matter under the action of the bipolar high-efficiency cyclone hybrid spray tower;

[0009] S201, controlling the environmental conditions of the VOCs waste gas treated by the bipolar high-efficiency cyclone hybrid spray tower, and introducing the VOCs waste gas into the secondary packing spray absorption tower to wash and absorb the soluble VOCs components in the VOCs waste gas, thereby completing the pretreatment of the VOCs waste gas;

[0010] S301, introducing the pre-treated VOCs waste gas into the uniform air mixed flow area at the front section of the biofilter bed, adjusting the environmental conditions of the pre-treated VOCs waste gas through the uniform air mixed flow area and uniformly introducing the adjusted VOCs waste gas into the composite biological filler area at the rear section of the biofilter bed, and the active microorganisms attached to the composite biological filler area degrade the organic matter in the VOCs waste gas through highly catalytically active biological enzymes to convert them into inorganic matter and store them in the circulating water collection pool;

[0011] S401, the inorganic substances are circulating water and carbon dioxide, and when the conductivity of the circulating water in the circulating water collection pool exceeds 10000 μs / cm, the circulating water is diluted to make the conductivity of the circulating water lower than 10000 μs / cm;

[0012] S501, the circulating water is purified twice by a coupled deep oxidation absorber and three times by a demister absorber and is stored again in a circulating water pool.

[0013] The above technical solution produces the following technical effects:

[0014] The technical solution of the present application realizes for the first time the real-time automatic control and optimization of conductivity, sludge concentration and multiple variables in the VOCs waste gas treatment and wastewater recycling process. Through the systematic optimization of the four key links of waste gas pretreatment, intelligent regulation of biological filter beds, dynamic regulation of conductivity and deep purification of circulating water, the long-term technical defects of the existing biological filter bed treatment technology in terms of conductivity accumulation, uncontrolled sludge concentration and water quality fluctuations are effectively solved, ensuring that the treatment efficiency is stable at more than 90% for a long time, and the conductivity fluctuation is stable within the range of ±500μS / cm, greatly reducing the operating cost and the risk of secondary pollution.

[0015] As a further improvement of the intelligent and efficient composite biological filter bed wastewater reuse process of the present invention, the composite biological filler area contains at least one of ceramsite, volcanic rock, PP ball, bamboo charcoal and sponge.

[0016] As a further improvement of the intelligent and efficient composite biofilter wastewater reuse process of the present invention, in step S301, the environmental conditions include the temperature and humidity of the VOCs waste gas, and a humidity sensor is provided in the uniform air mixing zone, and the humidity sensor monitors the relative humidity of the VOCs waste gas introduced into the uniform air mixing zone in real time;

[0017] When the relative humidity of VOCs exhaust gas is lower than the set value, the spray circulating water will be automatically turned on in the uniform mixed flow area;

[0018] When the relative humidity of VOCs exhaust gas is greater than or equal to the set value, the spraying volume in the uniform mixed flow area will automatically decrease or stop.

[0019] As a further improvement of the intelligent and efficient composite biofilter wastewater reuse process of the present invention, a spray nozzle or an atomizing nozzle is arranged inside the biofilter or in the uniform air mixed flow area, and the humidity is increased by quantitatively spraying circulating water or fresh water into the uniform air mixed flow area, and the set value range is: 60%RH-80%RH.

[0020] As a further improvement of the intelligent and efficient composite biological filter bed wastewater reuse process of the present invention, a temperature sensor is provided in the uniform air mixing flow area. When the temperature of the VOCs waste gas in the uniform air mixing flow area is not between 10°C and 42°C, the temperature of the VOCs waste gas is adjusted.

[0021] As a further improvement of the intelligent high-efficiency composite biofilter wastewater reuse process of the present invention, in step S101, the VOCs waste gas enters the bipolar high-efficiency cyclone hybrid spray tower along the tangential direction, and the VOCs waste gas is combined with the spray liquid impact in the bipolar high-efficiency cyclone hybrid spray tower under the action of centrifugal force to quickly intercept and filter the particulate matter;

[0022] The particulate matter is one or more of fluff, grease, and dust.

[0023] As a further improvement of the intelligent and efficient composite biofilter bed wastewater reuse process of the present invention, the deep oxidation absorption tower uses UV / O3 synergistic oxidation;

[0024] Among them, the ozone dosage is 50mg / L-100 mg / L, and the ultraviolet wavelength is 254nm.

[0025] As a further improvement of the intelligent and efficient composite biofilter wastewater reuse process of the present invention, the environmental conditions in step S201 and step S301 both involve the pH value of the VOCs waste gas;

[0026] When the pH value of the VOCs waste gas does not meet the range of 6.5-7.5, the pH value of the VOCs waste gas is adjusted to meet the range of 6.5-7.5 by controlling the dosing system.

[0027] As a further improvement of the intelligent and efficient composite biofilter wastewater reuse process of the present invention, the biofilter includes a microbial environment support system, which monitors and adjusts the water quality indicators of active microorganisms attached to the composite biological filler area in the biofilter.

[0028] The second purpose of the present invention is to provide an intelligent and efficient composite biological filter bed wastewater reuse system to solve the technical defect of increasingly low system processing efficiency in view of the shortcomings of the prior art.

[0029] In order to achieve the above-mentioned invention objectives, this application implements the following technical solutions:

[0030] An intelligent and efficient composite biofilter bed wastewater reuse system comprises any of the above-mentioned intelligent and efficient composite biofilter bed wastewater reuse processes.

[0031] The above technical solution produces the following technical effects:

[0032] This system achieves precise control over the entire process of VOCs waste gas treatment. The intelligent control module can automatically adjust the operating parameters of key links such as waste gas pretreatment, biofilter bed environmental conditions, and circulating water purification based on real-time monitoring data to ensure that the system is always in the optimal operating state. In addition, this system also has fault warning and self-repair functions. Once an abnormal situation occurs, the system can respond quickly and take measures, effectively avoiding problems such as reduced treatment efficiency or system shutdown caused by faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 The present invention provides a flow chart of the intelligent and efficient composite biofilter wastewater reuse process. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0036] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Although the present application is disclosed as above in the form of a preferred embodiment, it is not intended to limit the claims. Any person skilled in the art may make several possible changes and modifications without departing from the concept of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

[0038] The known biofilter bed technology is based on the fact that active microorganisms attached to porous and moist media use organic matter in the exhaust gas as energy and nutrients for their life activities, grow, reproduce, and expand their populations. In the process, a large number of bio-enzyme catalysts are produced. Microorganisms rely on the highly catalytic bio-enzymes they produce to degrade organic matter, thereby converting it into simple inorganic substances, such as CO2, H2O, or cell components.

[0039] The organic matter in the waste gas must first undergo a mass transfer process from the gas phase to the liquid phase, and then the organic components dissolved in the liquid phase are further diffused to the biofilm around the medium under the promotion of concentration difference and then captured and absorbed by the microorganisms therein. Under this condition, the pollutants that enter the microorganisms are decomposed as energy and nutrients in their own metabolic process. Part of the metabolites produced are dissolved in the liquid phase, part is used as cell substances or cell metabolic energy, and another part, such as CO2, is precipitated into the air. The organic matter in the waste gas is continuously reduced through the above process and thus purified.

[0040] However, volatile organic compounds (VOCs), as pollutants widely present in industrial production, are usually discharged in industrial waste gas, which poses great harm to the environment and human health. Although traditional treatment methods such as activated carbon adsorption and catalytic combustion can partially remove VOCs, they have disadvantages such as high treatment cost, easy to produce secondary pollution, and poor operation stability. In contrast, biofilter bed technology is widely used in VOCs waste gas treatment in the industrial field because of its advantages such as high efficiency in removing organic waste gas pollutants, low investment and operation costs, and environmental friendliness.

[0041] The biofilter bed uses active microorganisms attached to the surface of composite fillers (porous materials such as ceramsite, volcanic rock, bamboo charcoal, etc.) to use VOCs in the exhaust gas as a carbon source and energy. In an aerobic environment, it uses highly efficient catalytic enzymes secreted by its own metabolism to degrade organic pollutants in the exhaust gas into harmless water (circulating water) and simple inorganic substances such as carbon dioxide, thereby achieving pollution control. And as national and regional environmental protection policies become stricter, industrial enterprises are in urgent need of an efficient, economical and stable VOCs control technology. The biofilter bed technology is not only economical, but also can operate stably for a long time without the generation of secondary pollutants. It is suitable for long-term application in PCB manufacturing, electronics manufacturing, coating production, chemical manufacturing, lithium battery production and other industries. Therefore, this technology has been recognized and promoted by more and more industries.

[0042] Furthermore, although the existing biofilter technology has the above advantages, in actual application, the circulating water formed after the waste gas is treated by the biofilter often exposes the following prominent technical problems during long-term circulation:

[0043] 1) Serious accumulation effect of circulating water conductivity: With the repeated use of circulating water, dissolved salts in the water gradually accumulate, causing the conductivity to increase; when the conductivity exceeds 10,000 μS / cm, it will significantly inhibit the metabolic activity of microorganisms and reduce the system treatment efficiency by more than 30%;

[0044] 2) Sludge concentration is out of control and oxygen mass transfer efficiency is low: Long-term circulation of wastewater can easily lead to sludge concentration exceeding 5g / L. Sludge accumulation will block the gaps in the filler and reduce the oxygen mass transfer efficiency;

[0045] In addition, local hypoxic areas are formed, resulting in anaerobic metabolism and the release of odorous pollutants such as H2S, which reduces purification efficiency;

[0046] 3) Difficulty in dynamic adjustment of multiple variables: There is a strong coupling relationship between conductivity, COD, pH, and DO, and traditional manual or simple control methods cannot achieve real-time and efficient coordination; system parameters cannot be accurately controlled, and the circulating water volume fluctuates in a large range (±25%), which makes it difficult to meet the long-term stable operation requirements of the biofilter bed.

[0047] In summary, the difficulty in accurately controlling the conductivity of circulating water, the high sludge concentration, and the difficulty in real-time coordination and optimization of multiple variables are key issues that urgently need to be addressed in existing biofilter bed technology.

[0048] In order to solve the above technical defects, the present application has made improvements to the biological filter bed wastewater reuse process. Specifically, the intelligent and efficient composite biological filter bed wastewater reuse process of the present application includes the following steps:

[0049] S101. The VOCs waste gas generated by the waste gas generation source is collected through the pipe network and enters a bipolar high-efficiency cyclone hybrid spray tower along the tangent direction under the traction force of the fan. The VOCs waste gas is quickly intercepted and filtered for particulate matter under the action of the bipolar high-efficiency cyclone hybrid spray tower;

[0050] S201, controlling the environmental conditions of the VOCs waste gas treated by the bipolar high-efficiency cyclone hybrid spray tower, and introducing the VOCs waste gas into the secondary packing spray absorption tower to wash and absorb the soluble VOCs components in the VOCs waste gas, thereby completing the pretreatment of the VOCs waste gas;

[0051] S301, introducing the pre-treated VOCs waste gas into the uniform air mixed flow area at the front section of the biofilter bed, adjusting the environmental conditions of the pre-treated VOCs waste gas through the uniform air mixed flow area and uniformly introducing the adjusted VOCs waste gas into the composite biological filler area at the rear section of the biofilter bed, and the active microorganisms attached to the composite biological filler area degrade the organic matter in the VOCs waste gas through highly catalytically active biological enzymes to convert them into inorganic matter and store them in the circulating water collection pool;

[0052] S401, the inorganic substances are circulating water and carbon dioxide, and when the conductivity of the circulating water in the circulating water collection pool exceeds 10000 μs / cm, the circulating water is diluted to make the conductivity of the circulating water lower than 10000 μs / cm;

[0053] S501, the circulating water is purified twice by a coupled deep oxidation absorber and three times by a demister absorber and is stored again in a circulating water pool.

[0054] In the above technical solution, the circulating water collection pool used in this application is equipped with an online conductivity sensor (with a detection range of 0~20000μS / cm) for real-time monitoring; when the conductivity of the circulating water exceeds the set threshold (10000μS / cm), the water replenishment control valve is automatically opened, and fresh water is dynamically added to dilute the conductivity back to a safe range; prevent the conductivity from exceeding the microbial tolerance limit, ensure the long-term stability of microbial activity, and maintain efficient processing capacity.

[0055] In addition, this application also considers that the pollutants that produce secondary pollution in circulating water mainly include a small amount of wastewater and sludge. The wastewater produced per month for every 10,000 wind volume exhaust gas is 1 m³ and the sludge is 5L. The circulating water in the circulating water tank contains the accumulated conductivity and sludge in operation. High conductivity will affect the metabolic activity of microorganisms. Excessive sludge concentration will also lead to an increase in the oxygen consumption rate, which is prone to insufficient dissolved oxygen and hypoxia, thereby affecting the growth and reproduction of microorganisms. Therefore, when the water quality conductivity is greater than 10000μS / cm and the biological sludge concentration is greater than 5g / L, it is necessary to automatically control the drainage and sludge discharge to ensure that the microorganisms are in the best growth environment and continuously, efficiently and stably purify the VOCs waste gas. If the system is limited in the discharge of wastewater or sludge, it can be coupled with the waste (medium) water system, discharged to the temporary storage tank, and treated on-site through the AO process to further reduce COD (sludge), and partially reused after treatment to further reduce the discharge volume.

[0056] Furthermore, the composite biological filler area contains at least one of ceramsite, volcanic rock, PP ball, bamboo charcoal, and sponge. The porosity of ceramsite is 40%, the density is low, and the mechanical strength is moderate;

[0057] Volcanic rock has a large surface area, is easy to form a biofilm, and has a light texture; bamboo charcoal has a high adsorption capacity and has a preliminary adsorption and buffering effect on a variety of difficult-to-degrade organic matter. Therefore, the composite biological filler area provides a rich microbial attachment surface and a suitable microbial growth environment by combining the advantages of the above different materials. The porous structure of materials such as ceramsite and volcanic rock is conducive to the attachment and growth of microorganisms, and at the same time provides a good oxygen mass transfer channel to ensure the oxygen demand of microorganisms in the process of degrading organic matter. Materials such as PP balls and sponges have good water flow distribution performance, which helps the exhaust gas to fully contact the circulating water and improve the degradation efficiency of organic matter.

[0058] Furthermore, this technology introduces conductivity (TDS) suppression factor and multi-objective optimization mechanism on the basis of traditional Monod dynamics.

[0059] The microbial growth kinetic equation is:

[0060]

[0061] In the above formula, X is the microbial concentration (g / L); S is the substrate (COD or biodegradable VOCs) concentration (mg / L); DO is dissolved oxygen (mg / L); is the TDS concentration corresponding to the conductivity (μS / cm converted to mg / L or equivalent proportional value); and the other parameters are calibrated by fitting experiments.

[0062] In the equation Parameters such as these are usually calibrated through small or pilot tests, reflecting the actual growth of microorganisms under different COD (or VOCs concentration), dissolved oxygen and salinity (TDS) conditions.

[0063] During engineering design, the model can be used to estimate the biomass growth rate and substrate removal amount, thereby rationally determining key parameters such as biofilter bed filler height, residence time and spray load, and avoiding blind design that results in wasted investment or insufficient treatment efficiency.

[0064] In the model It reflects the inhibitory effect of salinity (conductivity) on microbial growth. When the online monitored conductivity rises to a certain threshold, this item can be used to quantitatively judge the degree of inhibition, thereby determining the amount of fresh water required to dilute the TDS back to an acceptable range (such as 8000~10000 μS / cm), protect microbial activity and maintain treatment efficiency. At the same time, it is worth noting that the above model is a setting mechanism for determining the conductivity threshold of -10000 μS / cm in this application. When a conductivity inhibition tendency is detected, fresh water can be added in time for dilution to ensure that the circulating water conductivity is within a narrow fluctuation range (such as ±500 μS / cm), thereby improving the availability and safety of the circulating water; at the same time, the direct discharge of wastewater is reduced to achieve water conservation, emission reduction and green production.

[0065] It is worth noting that once the model parameters are determined through small / medium-scale tests, this model can be reused or quickly calibrated to a certain extent in different industries (such as PCB, chemical industry, lithium battery, etc.); and it can be combined with the SCADA / DCS system to achieve continuous automatic monitoring, which is convenient for remote or unattended operation management.

[0066] Furthermore, the bipolar high-efficiency cyclone hybrid spray tower mentioned in this application is mainly used to remove large particles, grease and flocs in VOCs waste gas, and preliminarily adjust the pH, temperature and humidity of the gas. When the waste gas enters the spray tower along the tangential direction, the centrifugal force (centrifugal acceleration ≥ 5g) is combined with the impact of the spray liquid to improve the efficiency of impurity removal; at the same time, the pH of the gas is controlled by adding reagents such as NaOH / HCl in the spray tower to maintain the appropriate range required by microorganisms; and pretreatment can reduce the burden on the subsequent biological filter bed.

[0067] Among them, the secondary filler spray absorption tower is mainly used to absorb soluble VOCs components and stabilize the exhaust gas concentration and humidity. It uses PP or PVC fillers (specific surface area ≥ 300 m² / m³) and uses the spray liquid with surfactants or absorbents to absorb soluble or partially polar VOCs; most of the soluble pollutants in the gas after pretreatment have been captured, which can significantly reduce the load fluctuation of the biofilter bed.

[0068] Furthermore, the biofilter bed mentioned in this application is mainly divided into two sections: a uniform mixed flow zone and a composite biological filler zone. Among them, the uniform mixed flow zone uses a porous guide plate (opening rate 30% to 50%) or a grid-shaped flow equalization device to ensure that the exhaust gas is evenly distributed before entering the biological filter layer; it has built-in temperature, humidity and pH sensors to monitor the microenvironment in real time. The setting of the sensor makes the exhaust gas flow rate, temperature, humidity and pH more uniform to avoid local overload of microorganisms; thereby, concentration fluctuations (such as intermittent emissions) are suppressed, making the rear-end biological filter area more stable. The filler composition in the composite biological filler area will not be repeated here.

[0069] Furthermore, for waste gas with extremely high treatment requirements or containing a small amount of difficult-to-biodegrade components, this solution can be equipped with a deep oxidation absorption tower and a demister absorber to achieve secondary or tertiary enhanced purification. Among them, the deep oxidation absorption tower adopts UV / O3 synergistic oxidation, the ozone dosage is 50-100 mg / L, and the ultraviolet wavelength is 254 nm; for some difficult-to-degrade components (benzene series, aldehydes and ketones, etc.), they can be further oxidized into easily biodegradable or low-toxic intermediates; the treatment efficiency is increased to ≥95%. The demister absorber can intercept aerosol mist and trace residual VOCs;

[0070] Its exported non-methane total hydrocarbons can be stabilized at ≤10 mg / m³, meeting more stringent environmental protection standards.

[0071] In addition, this application also uses an intelligent control system that can monitor the environmental conditions in the biofilter bed (such as temperature, humidity, pH value, etc.) and the water quality parameters of the circulating water (such as conductivity, COD, etc.) in real time. According to the monitoring data, the intelligent control system can automatically adjust the spraying volume, water replenishment volume, drainage volume and other parameters to keep the environmental conditions in the biofilter bed in the optimal state, while ensuring that the water quality of the circulating water meets the growth requirements of microorganisms. This intelligent control method not only improves the processing efficiency of the system, but also reduces the operating cost and maintenance difficulty.

[0072] In summary, the intelligent and efficient composite biofilter wastewater reuse process and system provided in this application realizes precise control of the entire VOCs waste gas treatment process by precisely controlling the operating parameters of key links such as waste gas pretreatment, biofilter environmental conditions, and circulating water purification. The system not only has the ability to efficiently remove organic waste gas pollutants, but also has the advantages of low investment and operating costs and environmental friendliness. It is suitable for multiple industries such as PCB manufacturing, electronic manufacturing, coating production, chemical manufacturing, and lithium battery production.

[0073] The present invention is further described in detail below in conjunction with specific implementation modes, but the implementation modes of the present invention are not limited thereto.

[0074] Example 1

[0075] background:

[0076] Waste gas flow: 100,000 m³ / h; main VOCs are benzene, toluene and alcohols;

[0077] Biofilter spraying liquid crystal drainage: about 50 m³ / d;

[0078] Initial wastewater COD: 320 mg / L, conductivity: 10500 μS / cm, sludge concentration: 6.8 g / L.

[0079] Process:

[0080] Pretreatment: Bipolar cyclone spray tower + secondary packed tower to remove dust and most soluble VOCs;

[0081] Biofilter bed: filler thickness 1.5 m, composite filler ratio: ceramsite: volcanic rock: bamboo charcoal = 3:2:1 (volume ratio);

[0082] Wastewater reuse:

[0083] Gradient flocculation sedimentation: adding PAC (50 mg / L) + PAM (0.5 mg / L), controlling the sedimentation flow rate to 0.2 m / s;

[0084] Add fresh water Q according to the formula The conductivity was controlled at 8500±500 μS / cm. The carbon source and aeration volume were adjusted by fuzzy PID to maintain COD at 180±20 mg / L and pH=7.0±0.3.

[0085] As a result, this embodiment reduces the fluctuation of the traditional process from ±1500 μS / cm to ±500 μS / cm; the COD removal rate reaches an average of 93%, an increase of 24% compared with the traditional 75%; the sludge yield is reduced from 8 g / L to 4.5 g / L, a decrease of 43.75%; the operation and maintenance cost is about 0.5 yuan / cubic meter, which is significantly lower than the 1.8 yuan / cubic meter of the activated carbon adsorption system.

[0086] Example 2

[0087] background:

[0088] This embodiment is mainly used in waste gas and high humidity situations in the lithium battery industry. The waste gas to be treated contains alcohol solvents and has high humidity (≥80%RH);

[0089] The operating temperature of the biofilter bed is 25-35℃, and the conductivity easily accumulates to above 12000 μS / cm.

[0090] When the conductivity of the circulating water is about to exceed 12000 μS / cm, reverse osmosis concentration is started to discharge 10% to reduce salt accumulation; the remaining 90% of the circulating water is maintained in the range of 8000-10000 μS / cm; in addition, this embodiment adds an aeration and CO2 removal link to optimize the circulating water pH between 6.5 and 7.5.

[0091] In summary, the treatment efficiency of the system in this embodiment is stabilized at 89% to 93%, and the microorganisms still maintain good activity under high humidity conditions; the conductivity is prevented from being out of control through local salt discharge and reverse osmosis desalination; and the waste of water resources caused by simply replenishing large amounts of fresh water is avoided.

[0092] The rest of the details that are the same as those in Implementation 1 are not described in detail in this implementation.

[0093] Example 3

[0094] background:

[0095] This embodiment is applied under the condition of multi-component VOCs (esters, ketones) in the chemical industry, where there are a variety of volatile and partially difficult to biodegrade organic substances (such as esters and ketones) in the exhaust gas;

[0096] The biofilter bed is prone to produce odor when degrading esters, and the residual intermediate products may require post-treatment.

[0097] Process:

[0098] A UV / O3 deep oxidation tower + demister absorber is added at the rear end of the biological filter bed; an intelligent control system is used to adjust the O3 dosage to ensure oxidation efficiency; in addition, activated carbon filtration is added to the corresponding wastewater reuse link (to reduce odor and local soluble by-products).

[0099] Ultimately, the total removal rate of esters and ketones in this application is ≥95%; the organic load of the biofilter bed is stabilized at around 3.5 kgCOD / m³ filler·d, with no obvious anaerobic clogging; the wastewater reuse rate can reach 80%, requiring only a small amount of fresh water supplement (water supplement <20%).

[0100] The rest of the details that are the same as those in Implementation 1 are not described in detail in this implementation.

[0101] The above are only preferred implementations of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An intelligent and efficient composite biofilter wastewater reuse process, characterized in that: The steps include: S101, the VOCs waste gas generated by the waste gas generation source is collected through the pipe network and enters a bipolar high-efficiency cyclone hybrid spray tower along the tangential direction under the traction force of the fan, and the VOCs waste gas is quickly intercepted and filtered for particulate matter under the action of the bipolar high-efficiency cyclone hybrid spray tower; S201, controlling the environmental conditions of the VOCs waste gas treated by the bipolar high-efficiency cyclone hybrid spray tower, and introducing the VOCs waste gas into a secondary packing spray absorption tower to wash and absorb the soluble VOCs components in the VOCs waste gas, thereby completing the pretreatment of the VOCs waste gas; S301, introducing the VOCs waste gas after pretreatment into the uniform air mixed flow area at the front section of the biofilter bed, adjusting the environmental conditions of the VOCs waste gas after pretreatment through the uniform air mixed flow area and uniformly introducing the adjusted VOCs waste gas into the composite biological filler area at the rear section of the biofilter bed, and the active microorganisms attached to the composite biological filler area degrade the organic matter in the VOCs waste gas through highly catalytically active biological enzymes to convert them into inorganic matter and store them in a circulating water collection tank; S401, the inorganic substances are circulating water and carbon dioxide, and when the conductivity of the circulating water in the circulating water collection pool exceeds 10000 μs / cm, the circulating water is diluted to make the conductivity of the circulating water lower than 10000 μs / cm; S501, the circulating water is subjected to secondary purification by a coupled deep oxidation absorption tower and tertiary purification by a demisting absorber and is stored again in the circulating water pool.

2. According to the intelligent and efficient composite biofilter wastewater reuse process described in claim 1, it is characterized in that: The composite biological filler area contains at least one of ceramsite, volcanic rock, PP ball, bamboo charcoal and sponge.

3. The intelligent and efficient composite biofilter wastewater reuse process according to claim 1 is characterized in that: In the step S301, the environmental conditions include the temperature and humidity of the VOCs waste gas, the uniform wind mixed flow area is provided with a humidity sensor, and the humidity sensor monitors the relative humidity of the VOCs waste gas introduced into the uniform wind mixed flow area in real time; When the relative humidity of the VOCs waste gas is lower than the set value, the spray circulating water is automatically turned on in the uniform air mixed flow area; When the relative humidity of the VOCs waste gas is greater than or equal to the set value, the spraying amount in the uniform air mixed flow area is automatically reduced or stopped.

4. The intelligent and efficient composite biofilter wastewater reuse process according to claim 3 is characterized in that: A spray nozzle or atomizing nozzle is arranged inside the biological filter bed or in the uniform air mixed flow area, and the humidity is increased by quantitatively spraying circulating water or fresh water to the uniform air mixed flow area. The setting value range is: 60%RH-80%RH.

5. The intelligent and efficient composite biofilter wastewater reuse process according to claim 3 is characterized in that: The uniform air mixed flow area is provided with a temperature sensor, and when the temperature of the VOCs waste gas in the uniform air mixed flow area is not between 10° C. and 42° C., the temperature of the VOCs waste gas is adjusted.

6. The intelligent and efficient composite biofilter wastewater reuse process according to claim 1 is characterized in that: In the step S101, the VOCs waste gas enters the bipolar high-efficiency cyclone hybrid spray tower along the tangential direction, and the VOCs waste gas is combined with the spray liquid impact in the bipolar high-efficiency cyclone hybrid spray tower under the action of centrifugal force to quickly intercept and filter the particulate matter; Wherein, the particulate matter is one or more of fluff, grease, and dust.

7. The intelligent and efficient composite biofilter wastewater reuse process according to claim 1 is characterized in that: The deep oxidation absorption tower uses UV / O3 synergistic oxidation; Among them, the ozone dosage is 50mg / L-100 mg / L, and the ultraviolet wavelength is 254nm.

8. The intelligent and efficient composite biofilter wastewater reuse process according to claim 1 is characterized in that: The environmental conditions in step S201 and step S301 both involve the pH value of the VOCs waste gas; When the pH value of the VOCs waste gas does not meet the range of 6.5-7.5, the pH value of the VOCs waste gas is adjusted to meet the range of 6.5-7.5 by controlling the dosing system.

9. The intelligent and efficient composite biofilter wastewater reuse process according to claim 1 is characterized in that: The biofilter bed includes a microbial environment support system, which monitors and adjusts the water quality index of active microorganisms attached to the composite biological filler area in the biofilter bed.

10. An intelligent and efficient composite biofilter wastewater recycling system, characterized in that The invention comprises the intelligent and efficient composite biofilter bed wastewater reuse process as described in any one of claims 1 to 9.

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