High-arsenic high-salt wastewater discharge device and low-temperature operation method

Abstract

The present application relates to the field of wastewater treatment, and particularly relates to a high-arsenic and high-salt wastewater discharge device and a low-temperature operation method. The method comprises the following steps: obtaining water production flow data, inlet water pressure data and environmental temperature data; calculating a water quantity stability parameter representing the fluctuation degree of water production in a target time period; calculating a temperature fluctuation parameter representing the fluctuation amount of environmental temperature in the target time period; comparing the water production flow data with the average water production flow data to calculate a low-temperature deviation amount representing the influence degree of low temperature on the permeation membrane at each time point in the target time period; determining a fouling degree parameter of inorganic salt on the surface of the permeation membrane in the target time period; calculating a descaling index representing the membrane pollution condition at the target time point; and triggering and executing a corresponding countermeasure based on the size relationship between the descaling index at the target time point and a preset descaling threshold. The present application can improve the low-temperature operation stability of the high-arsenic and high-salt wastewater treatment system.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to a high-arsenic, high-salt wastewater discharge device and a low-temperature operation method. Background Technology

[0002] High-arsenic and high-salt wastewater is a special type of industrial wastewater, with arsenic (As) and salt (chloride, sulfate and other inorganic salts) content significantly higher than that of common wastewater standards.

[0003] Specifically, the arsenic concentration in this type of wastewater typically exceeds 0.5 mg / L (referring to the limit in the Integrated Wastewater Discharge Standard GB8978-1996), and can even reach tens to hundreds of milligrams per liter. It mainly originates from industrial processes such as mining, metallurgy, chemical production, and pesticide manufacturing. Arsenic in this wastewater often exists in the form of arsenate (As(V)) or arsenite (As(III)), characterized by high toxicity, high carcinogenic risk, and easy accumulation in the environment. On the other hand, its salt content (calculated as total dissolved solids (TDS)) is generally higher than 10,000 mg / L, and in extreme cases can exceed 100,000 mg / L, containing a large amount of sodium ions (Na₂O₃). + ), chloride ions (Cl) - ), sulfate ions (SO4) 2- These factors, such as the presence of corrosive substances and high osmotic pressure, not only cause scale buildup on equipment surfaces but also significantly inhibit the activity of microorganisms.

[0004] For the treatment of this type of wastewater, integrated discharge devices based on reverse osmosis technology are typically used. These devices separate salts, arsenic, and other harmful substances from the wastewater using semi-permeable membranes, achieving compliant discharge or reuse. This is currently a commonly used process for desalination of high-salinity wastewater.

[0005] In actual operation, especially in low-temperature environments, the performance of reverse osmosis membranes is significantly affected. Decreasing temperature leads to increased water viscosity and reduced molecular diffusion rates, thereby decreasing membrane flux (i.e., permeate flow). To ensure stable system operation under low-temperature conditions, conventional practices include placing reverse osmosis or nanofiltration membrane modules indoors or in an insulated box, adopting low-flux operation modes, and periodically flushing with warm water to prevent scaling and freezing. Although optimizing membrane materials and operating pressure can mitigate the efficiency loss caused by low temperatures to some extent, the aforementioned problems remain unresolved.

[0006] In existing technologies, when a decrease in permeate flow is detected, the common approach is to directly increase the temperature to attempt to restore membrane performance. However, a decrease in permeate flow is not always caused by low temperature; it may also stem from inorganic salt scaling on the membrane surface. Incorrectly increasing the temperature when scaling has already occurred may accelerate pollutant gelation and hard scale formation, exacerbating membrane blockage, leading to misdiagnosis and wasted energy. Therefore, accurately distinguishing whether the main cause of the decreased permeate flow is the low-temperature effect or scaling, and implementing targeted adjustments accordingly, is crucial for improving the operational stability and energy efficiency of high-arsenic and high-salt wastewater treatment devices in low-temperature environments. Summary of the Invention

[0007] This invention provides a high-arsenic, high-salt wastewater discharge device and a low-temperature operation method to solve existing problems.

[0008] The low-temperature operation method of the high-arsenic and high-salt wastewater discharge device of the present invention adopts the following technical solution:

[0009] One embodiment of the present invention provides a low-temperature operation method for a high-arsenic and high-salt wastewater discharge device, the method comprising the following steps:

[0010] Acquire water production flow rate data, inlet water pressure data, and ambient temperature data;

[0011] Based on the water production flow data at each time point within the target duration before the target time point, calculate the water stability parameter that characterizes the degree of water production fluctuation within the target duration.

[0012] Based on the ambient temperature data at each time point within the target duration, calculate the temperature fluctuation parameter that characterizes the amount of ambient temperature fluctuation within the target duration.

[0013] The permeate flow rate data at each time point within the target duration is compared with the mean permeate flow rate data at all time points. Combined with the water flow stability parameter and temperature fluctuation parameter within the target duration, the low temperature deviation, which characterizes the degree of influence of low temperature on the permeate membrane at each time point within the target duration, is calculated.

[0014] Based on the ratio of the change in influent pressure to the change in permeate flow rate within the target duration, the scaling parameters of inorganic salts on the permeate membrane surface within the target duration are determined.

[0015] Based on the scaling degree parameters and low temperature deviation within the target time period, a descaling index characterizing the membrane fouling status at the target time point is calculated.

[0016] Based on the relationship between the descaling index at the target time point and the preset descaling threshold, the corresponding response strategy is triggered and executed.

[0017] Optionally, based on the water production flow data at each time point within the target duration prior to the target time point, a water stability parameter characterizing the degree of water production fluctuation within the target duration is calculated, specifically including:

[0018] Obtain the average permeate flow rate data at all time points within the target duration;

[0019] Calculate the absolute value of the difference between the water production flow rate data at each time point within the target duration and the mean value, and use it as the water volume fluctuation value at each time point;

[0020] Calculate the average value of water volume fluctuations at all time points within the target duration;

[0021] Taking the reciprocal of the average value yields the water stability parameter.

[0022] Optionally, based on the ambient temperature data at each time point within the target duration, a temperature fluctuation parameter characterizing the ambient temperature fluctuation within the target duration is calculated, specifically including:

[0023] Acquire ambient temperature data for all time points within the target duration to form an ambient temperature time series.

[0024] Calculate the absolute value of the difference between ambient temperature data at any two adjacent time points in an ambient temperature time series;

[0025] The average of all calculated absolute values ​​is used as the temperature fluctuation parameter.

[0026] Optionally, the permeate flow rate data at each time point within the target duration is compared with the average permeate flow rate data at all time points. Combined with the water flow stability parameter and temperature fluctuation parameter within the target duration, a low-temperature deviation, characterizing the degree of impact of low temperature on the permeable membrane at each time point within the target duration, is calculated. Specifically, this includes:

[0027] For any point in time within the target duration, determine the relationship between the water production flow rate data at that point in time and the average water production flow rate data.

[0028] Based on the judgment result of the size relationship, a direction factor is assigned to the time point. When the water production flow rate is less than the average water production flow rate, the direction factor is configured to the first preset value; otherwise, it is configured to the second preset value.

[0029] Calculate the ratio of the direction factor to the temperature fluctuation parameter;

[0030] Multiply the calculated ratio by the water stability parameter corresponding to the time point to obtain an initial deviation.

[0031] The initial deviations calculated at all time points within the target duration are normalized to obtain the low-temperature deviations corresponding to each time point.

[0032] Optionally, based on the ratio of the change in influent pressure to the change in permeate flow rate within the target duration, parameters for the degree of inorganic salt scaling on the membrane surface within the target duration are determined, specifically including:

[0033] Obtain the average influent pressure and average permeate flow rate for the target duration and its preceding adjacent duration;

[0034] Calculate the first difference between the average inlet pressure for the target duration and the average inlet pressure for the previous adjacent duration;

[0035] Calculate the second difference between the average water production over the target duration and the average water production over the previous adjacent duration;

[0036] The ratio of the first difference to the second difference is determined as the scaling degree parameter.

[0037] Optionally, based on the scaling degree parameters and low temperature deviation within the target time period, a descaling index characterizing the membrane fouling status at the target time point is calculated, specifically including:

[0038] Obtain the scaling degree parameters within the target time period;

[0039] Obtain the average value of the low temperature deviation at all time points within the target duration;

[0040] Calculate the ratio of the scaling degree parameter to the average low-temperature deviation;

[0041] The calculated ratios are normalized, and the result is determined as the descaling index.

[0042] Optionally, the preset descaling threshold includes a first threshold and a second threshold, wherein the first threshold is greater than the second threshold.

[0043] Optionally, based on the relationship between the descaling index at the target time point and the preset descaling threshold, a corresponding response strategy is triggered and executed, specifically including:

[0044] If the descaling index is greater than or equal to the first threshold, the descaling cleaning strategy is triggered and executed.

[0045] If the descaling index is less than the second threshold, a heating strategy will be triggered and executed.

[0046] If the descaling index is less than the first threshold but greater than or equal to the second threshold, the current operating status is maintained or a preventative monitoring strategy is implemented.

[0047] Optionally, after triggering and executing the heating strategy, the method further includes:

[0048] During the implementation of the heating strategy, the stability parameters of the water production rate are continuously monitored;

[0049] When the water production stability parameter is detected to reach or exceed the preset stability target value, the heating operation is stopped.

[0050] This invention proposes a high-arsenic, high-salt wastewater discharge device, characterized in that it comprises:

[0051] The data acquisition module includes: a permeate flow meter, installed on the permeate pipeline of the permeate membrane module, for acquiring permeate flow data; a pressure sensor, installed on the pipeline between the high-pressure pump outlet and the permeate membrane module inlet, for acquiring inlet pressure data; and a temperature sensor, for acquiring ambient temperature data.

[0052] The processing and control module is connected in communication with the data acquisition module and is configured to execute a low-temperature operation method for a high-arsenic and high-salt wastewater discharge device, and generate control commands based on the execution results.

[0053] The execution module, connected to the processing and control module, includes: a heating unit for performing a heating operation in response to control commands; and a cleaning unit for performing a descaling and cleaning operation in response to control commands.

[0054] The beneficial effects of the technical solution of the present invention are:

[0055] In this embodiment of the invention, a multi-dimensional monitoring system is constructed by deploying flow, pressure, and temperature sensors. Based on an algorithm model, parameters related to low-temperature deviation and scaling degree are calculated in real time. This allows for intelligent and accurate differentiation of the root cause of membrane performance degradation as either the low-temperature effect or inorganic salt scaling. Based on this, targeted heating or cleaning strategies are automatically triggered, achieving fully closed-loop automated operation from status perception and fault diagnosis to precise control. This method completely changes the traditional reliance on manual experience, which is prone to misjudgment and misoperation. While ensuring the low-temperature operational stability of high-arsenic and high-salt wastewater treatment systems, it significantly avoids the ineffective consumption of energy and reagents and effectively extends the service life of the permeate membrane modules, demonstrating outstanding advantages in intelligence, energy saving, and economy. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a flowchart illustrating a low-temperature operation method for a high-arsenic, high-salt wastewater discharge device, as provided in one embodiment of the present invention. Detailed Implementation

[0058] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a low-temperature operation method for a high-arsenic, high-salt wastewater discharge device proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0060] The following description, in conjunction with the accompanying drawings, details a specific scheme for a low-temperature operation method of a high-arsenic, high-salt wastewater discharge device provided by the present invention.

[0061] This invention provides a high-arsenic, high-salt wastewater discharge device and a low-temperature operation method. Please refer to [link / reference]. Figure 1 The diagram illustrates a flowchart of a low-temperature operation method for a high-arsenic, high-salt wastewater discharge device according to an embodiment of the present invention. The method includes the following steps:

[0062] S101. Obtain water production flow rate data, inlet water pressure data, and ambient temperature data.

[0063] For example, data acquisition in this embodiment mainly relies on three types of sensors:

[0064] Install an ultrasonic flow meter at the outlet of the permeate line of the osmotic membrane module. The recommended measuring range for this instrument is 0–10 m. 3 / h, with an accuracy of not less than ±0.5%, data is collected at a frequency of 3 times per second, and the flow time series in liters per minute or cubic meters per hour is continuously output. The type of ultrasonic sensor is electromagnetic or ultrasonic flow meter.

[0065] A strain gauge pressure sensor is installed on the pipe between the high-pressure pump outlet and the inlet of the permeate membrane module. The sensor is recommended to have a range of 0-6 MPa and an accuracy of ±0.25% of full scale. It also operates at a frequency of 3 times per second and outputs a pressure time series in megapascals.

[0066] Place digital temperature sensors (such as the DS18B20 model) in representative locations around the equipment (e.g., near the water inlet). The recommended temperature measurement range is -10°C to 50°C, with an accuracy of ±0.5°C, acquiring temperature data once per second to form a temperature change sequence.

[0067] The temperature sensor for the heating cable is installed at the membrane module's product inlet and the insulated pipes of the heating cable to monitor the temperature in the working area of ​​the heating cable in real time. The main function of the heating cable is to actively insulate the pipes in low-temperature environments, preventing the fluid inside from freezing or causing abnormal system operation due to excessively low temperatures. By precisely controlling the heating process in the pipes, it maintains a stable internal fluid temperature, thereby ensuring the continuous and efficient operation of the water treatment system. Technical parameters are: Sensor type: thermocouple or RTD temperature sensor; Measurement range: -40℃~150℃; Measurement accuracy: ±0.5℃; Sampling frequency: 3 times / second (3Hz); Data output format: Temperature value (unit: ℃), output in continuous time series format.

[0068] The output signals of all the aforementioned sensors are uniformly connected to a programmable logic controller (PLC) or a data acquisition module with equivalent functionality. During the acquisition process, a precise timestamp is added to each data point to ensure that the flow, pressure, and temperature data from different sensors correspond strictly in time sequence, facilitating subsequent fusion analysis. This timestamped data can be further transmitted to a local server or cloud platform for generating operating curves, assisting in anomaly identification, and historical trend analysis.

[0069] For example, the water production flow sequence is denoted as ,in, This represents the instantaneous flow rate value collected at second t, in liters per minute (L / min), with a sampling frequency of 3 times per second;

[0070] The inlet pressure sequence is denoted as ,in, This represents the pressure value collected in second t, in megapascals (MPa), with a sampling frequency of 3 times per second.

[0071] The ambient temperature sequence is denoted as ,in, This represents the temperature value collected in the t-th second, in degrees Celsius (°C), with a sampling frequency of once per second.

[0072] S102. Based on the water production flow data at each time point within the target duration before the target time point, calculate the water quantity stability parameter that characterizes the degree of water production fluctuation within the target duration.

[0073] In this embodiment, based on the water production flow data at each time point within the target duration prior to the target time point, a water volume stability parameter characterizing the degree of water production fluctuation within the target duration is calculated, specifically including:

[0074] Obtain the average permeate flow rate data at all time points within the target duration;

[0075] Calculate the absolute value of the difference between the water production flow rate data at each time point within the target duration and the mean value, and use it as the water volume fluctuation value at each time point;

[0076] Calculate the average value of water volume fluctuations at all time points within the target duration;

[0077] Taking the reciprocal of the average value yields the water stability parameter.

[0078] For example, the target time point can refer to the current moment, while the target duration can be defined as a preset time window preceding the current moment. For instance, if the current time is 4:00 and the preset duration is set to 30 minutes, then the target duration is the period from 3:31 to 4:00. The purpose of this setting is that the system always performs real-time analysis based on the most recent operational data, enabling timely responses to changes in operating conditions, rather than relying on fixed historical or initial data. Selecting an appropriate time window length (such as 30 minutes) ensures that it includes sufficient data samples to filter out transient interference and guarantee the stability of the analysis results, while also ensuring that the evaluation results reflect the latest state of the system and avoid response lag.

[0079] Therefore, the average water production flow rate data at all time points within the target duration, i.e., the water production rate, is determined based on the recent average flow rate level. Specifically, it is the average water production flow rate sampled for the half hour preceding the current time point (denoted as...). The arithmetic mean of the yields is taken as the water production for that period, and the calculation formula is as follows:

[0080] ;

[0081] in, This represents the average water flow rate over half an hour, i.e., the water production; N is the total number of sampling points during this period.

[0082] In obtaining water production Then, by combining the real-time flow rate value at the current moment, the stability of water volume fluctuations can be further evaluated. The formula for calculating the water volume stability parameter is:

[0083] ;

[0084] Where N is the total number of sampling points during that time period.

[0085] This formula quantifies real-time traffic. With average flow The overall deviation between the values. If the flow rate at each sampling time is very close to the mean, and the denominator approaches zero, the S value increases, indicating that the water production process is stable; conversely, if the flow rate fluctuates significantly, the S value decreases, reflecting lower stability.

[0086] S103. Based on the ambient temperature data at each time point within the target duration, calculate the temperature fluctuation parameter that characterizes the amount of ambient temperature fluctuation within the target duration.

[0087] In this embodiment, based on the ambient temperature data at each time point within the target duration, a temperature fluctuation parameter characterizing the ambient temperature fluctuation within the target duration is calculated, specifically including:

[0088] Acquire ambient temperature data for all time points within the target duration to form an ambient temperature time series.

[0089] Calculate the absolute value of the difference between ambient temperature data at any two adjacent time points in an ambient temperature time series;

[0090] The average of all calculated absolute values ​​is used as the temperature fluctuation parameter.

[0091] S104. Compare the permeate flow rate data at each time point within the target duration with the average permeate flow rate data at all time points, and combine the water flow stability parameter and temperature fluctuation parameter within the target duration to calculate the low temperature deviation, which characterizes the degree of influence of low temperature on the permeable membrane at each time point within the target duration.

[0092] In this embodiment, the permeate flow rate data at each time point within the target duration is compared with the average permeate flow rate data at all time points. Combined with the water flow stability parameter and temperature fluctuation parameter within the target duration, the low-temperature deviation, which characterizes the degree of influence of low temperature on the permeable membrane at each time point within the target duration, is calculated. Specifically, this includes:

[0093] For any point in time within the target duration, determine the relationship between the water production flow rate data at that point in time and the average water production flow rate data.

[0094] Based on the judgment result of the size relationship, a direction factor is assigned to the time point. When the water production flow rate is less than the average water production flow rate, the direction factor is configured to the first preset value; otherwise, it is configured to the second preset value.

[0095] Calculate the ratio of the direction factor to the temperature fluctuation parameter;

[0096] Multiply the calculated ratio by the water stability parameter corresponding to the time point to obtain an initial deviation.

[0097] The initial deviations calculated at all time points within the target duration are normalized to obtain the low-temperature deviations corresponding to each time point.

[0098] For example, in low-temperature environments, the increased viscosity of water during membrane treatment leads to a decrease in membrane flux, resulting in a lower-than-normal permeate flow rate. To quantify this deviation in water flow caused by low temperature, a low-temperature deviation is introduced as an evaluation index.

[0099] Low temperature deviation The calculation formula can be:

[0100] ;

[0101] in, This indicates the deviation of the low temperature at a certain moment; This indicates the water volume stability parameter for that period of time; This represents the average water flow (water production) during that period. This represents the real-time water flow rate at the current moment. For symbolic functions: when The value is 1 if it is true, and -1 otherwise. This represents the average of the absolute values ​​of the differences between adjacent temperature samples within that time period; that is, the temperature fluctuation parameter. This indicates a normalization process, ensuring that the results fall within a uniform range.

[0102] In this formula, the sign function is used to determine whether the real-time water production is lower than the average: if it is lower than the average, the function value is positive, which, combined with the temperature fluctuation parameter, amplifies the representation of the impact of low temperature; if it is higher than the average, the function value is negative, reflecting the recovery trend of water production. The water volume stability parameter S is used to adjust the weight of this judgment in the context of overall stability.

[0103] Optionally, in this embodiment, the direction factor can be either 1 or -1, and can be set according to actual needs. There is no restriction here; in this embodiment, it is used... The goal is to assign a directional factor to a given time point based on the judgment result of the size relationship.

[0104] In the formula, the direction factor is expressed through the sign function. This function outputs a positive value when the real-time water production is below the average, reflecting the flow inhibition that low temperature may cause; conversely, it outputs a negative value when the production is above the average, indicating a flow recovery trend.

[0105] Water stability parameters are used to weight the reliability of this trend; the higher the stability, the more meaningful the current trend is.

[0106] The temperature fluctuation parameter is the average absolute value of the temperature difference between adjacent temperatures within that period, reflecting the degree of fluctuation in ambient temperature. The greater the temperature fluctuation, the more cautious one needs to be in assessing the impact of low temperatures.

[0107] S105. Based on the ratio of the change in influent pressure to the change in permeate flow rate within the target duration, determine the scaling parameters of inorganic salts on the permeate membrane surface within the target duration.

[0108] In this embodiment, based on the ratio of the change in influent pressure to the change in permeate flow rate within the target duration, the scaling degree parameter of inorganic salts on the permeate membrane surface within the target duration is determined, specifically including:

[0109] Obtain the average influent pressure and average permeate flow rate for the target duration and its preceding adjacent duration;

[0110] Calculate the first difference between the average inlet pressure for the target duration and the average inlet pressure for the previous adjacent duration;

[0111] Calculate the second difference between the average water production over the target duration and the average water production over the previous adjacent duration;

[0112] The ratio of the first difference to the second difference is determined as the scaling degree parameter.

[0113] For example, in this embodiment, it is necessary to distinguish whether the decrease in permeate flow is due to the low temperature effect or inorganic salt scaling on the membrane surface. Since both can lead to a decrease in flux, if scaling is mistakenly attributed to the low temperature effect and a heating operation is performed, it may actually accelerate the gelation of pollutants and promote the formation of hard scale, thereby aggravating membrane fouling.

[0114] Therefore, a scaling degree judgment method based on the pressure-flow response relationship is introduced. Specifically, if the decrease in water production is mainly caused by low temperature, then appropriately increasing the inlet water pressure should significantly improve the water production; if it is mainly caused by scaling, then increasing the pressure will have a limited effect on improving the water production.

[0115] The formula for calculating the scaling degree parameter can be:

[0116] ;

[0117] in, Parameters indicating the degree of scaling. and These represent the average inlet water pressure for the current half hour and the previous half hour, respectively. and These represent the average water production during the corresponding time period.

[0118] This parameter reflects the percentage increase in water production corresponding to a unit increase in pressure. If A smaller value indicates that increased pressure significantly increases water production, the membrane is sensitive to pressure changes, and the likelihood of scaling is low; if... A larger value indicates that the pressure increase does not significantly improve the permeate production, the membrane permeability is significantly affected by scaling, and the degree of scaling is high.

[0119] S106. Based on the scaling degree parameters and low temperature deviation within the target time period, calculate the descaling index that characterizes the membrane fouling status at the target time point.

[0120] In this embodiment, based on the scaling degree parameter and low temperature deviation within the target time period, a descaling index characterizing the membrane fouling status at the target time point is calculated, specifically including:

[0121] Obtain the scaling degree parameters within the target time period;

[0122] Obtain the average value of the low temperature deviation at all time points within the target duration;

[0123] Calculate the ratio of the scaling degree parameter to the average low-temperature deviation;

[0124] The calculated ratios are normalized, and the result is determined as the descaling index.

[0125] For example, to achieve intelligent operation control in low-temperature environments, decisions need to be made by comprehensively considering the impact of low temperature and the scaling condition. Therefore, a descaling index is introduced as a criterion, which comprehensively reflects two key pieces of information: deviation from low temperature and the degree of scaling.

[0126] The formula for calculating the descaling index is as follows:

[0127] ;

[0128] in, Indicates the descaling index, Parameters indicating the degree of scaling. This represents the average value of the low temperature deviation at all time points within the period, characterizing the overall impact of low temperature on membrane flux. This indicates normalization processing.

[0129] The physical meaning of this index lies in: if the scaling degree parameter The deviation is relatively large, and the average value of the low temperature deviation is also relatively large. Smaller, then A value approaching 1 indicates that the decrease in water production is mainly due to scaling, and in this case, the descaling and cleaning process should be initiated first; conversely, if... A low value indicates that the low temperature has a dominant effect, and measures should be taken to increase the temperature to restore the membrane performance.

[0130] By calculating the descaling index, the system can automatically identify the main cause of the decrease in water production and trigger corresponding heating or descaling strategies accordingly, thereby achieving precise and adaptive operation control.

[0131] S107. Based on the relationship between the descaling index at the target time point and the preset descaling threshold, trigger and execute the corresponding response strategy.

[0132] In this embodiment, the preset descaling threshold includes a first threshold and a second threshold, wherein the first threshold is greater than the second threshold.

[0133] Based on the relationship between the descaling index at the target time point and the preset descaling threshold, corresponding response strategies are triggered and executed, including:

[0134] If the descaling index is greater than or equal to the first threshold, the descaling cleaning strategy is triggered and executed.

[0135] If the descaling index is less than the second threshold, a heating strategy will be triggered and executed.

[0136] If the descaling index is less than the first threshold but greater than or equal to the second threshold, the current operating status is maintained or a preventative monitoring strategy is implemented.

[0137] After triggering and executing the heating strategy, the method also includes:

[0138] During the implementation of the heating strategy, the stability parameters of the water production rate are continuously monitored;

[0139] When the water production stability parameter is detected to reach or exceed the preset stability target value, the heating operation is stopped.

[0140] Optionally, the first threshold and the second threshold can be set according to actual needs, and there is no specific numerical limitation here. In a preferred embodiment, the first threshold can be set to 0.8 and the second threshold can be set to 0.4.

[0141] For example, the operating status of the membrane system can be graded based on the descaling index value, and corresponding control strategies can be implemented:

[0142] when When the concentration is ≥0.8, inorganic salt scaling on the membrane surface is severe, and the permeate flow rate is significantly lower than the design level. Immediately initiate a descaling and cleaning procedure to remove scale from the membrane surface and restore membrane flux. This threshold indicates that scaling has become the main factor affecting permeate flow, and chemical or physical cleaning should be prioritized.

[0143] When 0.4≤ When the value is <0.8, the membrane system exhibits some degree of scaling or fouling, but it is not severe enough to directly affect the stability of the produced water. In monitoring and preventative maintenance mode, regular inspections or light cleaning can be scheduled to prevent further scaling. This range indicates that scaling is within a controllable range and the system can still operate, but its changing trend needs to be monitored.

[0144] when When the viscosity is less than 0.4, scaling has a minor impact, and the decrease in permeate flow is mainly due to the increased viscosity of the water caused by low temperature. If the water flow stability parameter S is still lower than the set target (e.g., S < 1), a heating program is initiated to gradually increase the feed water temperature until the permeate flow stabilizes. Low temperature is currently the main factor limiting membrane performance; moderate heating can effectively improve fluid flow and increase membrane flux.

[0145] The high-arsenic, high-salt wastewater discharge equipment in this embodiment typically includes the following components: arsine and phosphine tail gas treatment equipment, arsenic-containing wastewater, a tap water tank, an air compressor system, an arsenic-containing wastewater treatment system, an MOCVD arsine and phosphine tail gas inlet, treated arsenic-containing waste gas, a PVC ball valve for the outlet, pipeline valves, liquid flow direction indicators, a liquid level sensor, a gas electric valve, a tap water inlet pipe, a liquid drain valve, compressed air drying pipeline, an electric heating tape control box, arsenic-containing wastewater pipelines, tap water outlet pipes, heating tape, and insulated pipelines. The main function of the heating tape is insulation, preventing the water in the pipeline from freezing or becoming too cold in low-temperature environments, thus affecting the normal operation of the system. By heating the inner and outer surfaces of the pipeline, the temperature of the water flowing inside the pipeline is kept stable, ensuring the continuity and efficiency of the water treatment process.

[0146] Under the conditions of k<0.4 and S<1, the temperature control system is started to heat the pipes, gradually increasing the temperature of the heat tracing pipes. By heating the heat tracing pipes, the viscosity of the fluid in the wastewater is reduced, ensuring that the water can flow smoothly through the system and restore the normal performance of the permeate membrane. At the same time, the water temperature is raised to the design operating range of the permeate membrane module until the water production rate tends to stabilize. The real-time temperature of the heat tracing pipe is monitored using a heat tracing temperature sensor.

[0147] The cleaning process is triggered when k ≥ 0.8, removing scale from the membrane surface through chemical cleaning or physical rinsing. Based on real-time monitoring of flow rate, pressure, temperature, and calculated parameters such as k and S, the system continuously optimizes the heating and cleaning strategies to ensure the membrane operates at a consistently high efficiency and stable state.

[0148] In summary, in this embodiment of the invention, by real-time monitoring of flow rate, pressure, and temperature data, and analyzing the stability of the produced water, the impact of low temperature, and the degree of scaling, the main cause of membrane performance degradation can be accurately identified as either the low-temperature effect or inorganic salt scaling. This allows for the automatic selection and execution of either heating or cleaning operations. This solution achieves intelligent diagnosis and autonomous control of the operating status of high-arsenic and high-salt wastewater treatment systems in low-temperature environments. It overcomes the shortcomings of traditional methods that rely on human experience and are prone to misjudgment. While ensuring stable system operation, it effectively avoids the waste of energy and reagents and helps extend the service life of key permeate membrane components, thus balancing operational reliability, economy, and treatment efficiency.

[0149] The present invention also proposes a high-arsenic and high-salt wastewater discharge device, comprising:

[0150] The data acquisition module includes: a permeate flow meter, installed on the permeate pipeline of the permeate membrane module, for acquiring permeate flow data; a pressure sensor, installed on the pipeline between the high-pressure pump outlet and the permeate membrane module inlet, for acquiring inlet pressure data; and a temperature sensor, for acquiring ambient temperature data.

[0151] The processing and control module is connected in communication with the data acquisition module and is configured to execute a low-temperature operation method for a high-arsenic and high-salt wastewater discharge device, and generate control commands based on the execution results.

[0152] The execution module, connected to the processing and control module, includes: a heating unit for performing a heating operation in response to control commands; and a cleaning unit for performing a descaling and cleaning operation in response to control commands.

[0153] It should be noted that the device provided in the above embodiments is only an example of the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer device can be divided into different functional modules to complete all or part of the functions described above.

[0154] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0155] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0156] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-temperature operation method for a high-arsenic, high-salt wastewater discharge device, characterized in that, include: Acquire water production flow rate data, inlet water pressure data, and ambient temperature data; Based on the water production flow data at each time point within the target duration prior to the target time point, water stability parameters characterizing the degree of water production fluctuation within the target duration are calculated, specifically including: Obtain the average permeate flow rate data at all time points within the target duration; Calculate the absolute value of the difference between the water production flow rate data at each time point within the target duration and the mean value, and use it as the water volume fluctuation value at each time point; Calculate the average value of water volume fluctuations at all time points within the target duration; Taking the reciprocal of the average value yields the water stability parameter; Based on the ambient temperature data at each time point within the target duration, temperature fluctuation parameters characterizing the ambient temperature fluctuation within the target duration are calculated, specifically including: Acquire ambient temperature data for all time points within the target duration to form an ambient temperature time series. Calculate the absolute value of the difference between ambient temperature data at any two adjacent time points in an ambient temperature time series; The average of all calculated absolute values ​​is used as the temperature fluctuation parameter. The permeate flow rate data at each time point within the target duration is compared with the average permeate flow rate data at all time points. Combined with water flow stability parameters and temperature fluctuation parameters within the target duration, the low-temperature deviation, which characterizes the degree of impact of low temperature on the permeable membrane at each time point within the target duration, is calculated. Specifically, this includes: For any point in time within the target duration, determine the relationship between the water production flow rate data at that point in time and the average water production flow rate data. Based on the judgment result of the size relationship, a direction factor is assigned to the time point. When the water production flow rate is less than the average water production flow rate, the direction factor is configured to the first preset value; otherwise, it is configured to the second preset value. Calculate the ratio of the direction factor to the temperature fluctuation parameter; Multiply the calculated ratio by the water stability parameter corresponding to the time point to obtain an initial deviation. The initial deviations calculated at all time points within the target duration are normalized to obtain the low-temperature deviations corresponding to each time point. Based on the ratio of the change in influent pressure to the change in permeate flow rate within the target duration, the scaling parameters of inorganic salts on the permeate membrane surface within the target duration are determined. Based on the scaling degree parameters and low temperature deviation within the target time period, a descaling index characterizing the membrane fouling status at the target time point is calculated, specifically including: Obtain the scaling degree parameters within the target time period; Obtain the average value of the low temperature deviation at all time points within the target duration; Calculate the ratio of the scaling degree parameter to the average low-temperature deviation; The calculated ratios are normalized, and the result is determined as the descaling index. Based on the relationship between the descaling index at the target time point and the preset descaling threshold, the corresponding response strategy is triggered and executed.

2. The low-temperature operation method of the high-arsenic and high-salt wastewater discharge device according to claim 1, characterized in that, The parameter for determining the degree of inorganic salt scaling on the membrane surface within the target time period, based on the ratio of the change in influent pressure to the change in permeate flow rate, specifically includes: Obtain the average influent pressure and average permeate flow rate for the target duration and its preceding adjacent duration; Calculate the first difference between the average inlet pressure for the target duration and the average inlet pressure for the previous adjacent duration; Calculate the second difference between the average water production over the target duration and the average water production over the previous adjacent duration; The ratio of the first difference to the second difference is determined as the scaling degree parameter.

3. The low-temperature operation method of the high-arsenic and high-salt wastewater discharge device according to claim 1, characterized in that, The preset descaling threshold includes a first threshold and a second threshold, wherein the first threshold is greater than the second threshold.

4. The low-temperature operation method of the high-arsenic and high-salt wastewater discharge device according to claim 1, characterized in that, The relationship between the descaling index at the target time point and the preset descaling threshold triggers and executes corresponding response strategies, specifically including: If the descaling index is greater than or equal to the first threshold, the descaling cleaning strategy is triggered and executed. If the descaling index is less than the second threshold, a heating strategy will be triggered and executed. If the descaling index is less than the first threshold but greater than or equal to the second threshold, the current operating status is maintained or a preventative monitoring strategy is implemented.

5. A low-temperature operation method for a high-arsenic, high-salt wastewater discharge device according to claim 4, characterized in that, After triggering and executing the heating strategy, the method further includes: During the implementation of the heating strategy, the stability parameters of the water production rate are continuously monitored; When the water production stability parameter is detected to reach or exceed the preset stability target value, the heating operation is stopped.

6. A high-arsenic, high-salt wastewater discharge device, characterized in that, include: The data acquisition module includes: The permeate flow meter is installed on the permeate pipeline of the permeate membrane module to obtain permeate flow data; A pressure sensor is installed on the pipe between the outlet of the high-pressure pump and the inlet of the permeate membrane module to acquire inlet water pressure data; Temperature sensor, used to acquire ambient temperature data; The processing and control module is communicatively connected to the data acquisition module and is configured to execute the low-temperature operation method of any one of claims 1-5, and generate control commands based on the execution results; The execution module, connected to the processing and control module, includes: A heating unit is used to perform a heating operation in response to control commands; The cleaning unit is used to perform descaling and cleaning operations in response to control commands.

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