A nereistoxin pesticide wastewater treatment process

Abstract

The application relates to the technical field of wastewater treatment, in particular to a processing technology for nereistoxin pesticide wastewater, which comprises the following steps: sequentially feeding the nereistoxin agricultural wastewater into a filter tank, a pH adjusting tank, a Fenton oxidation tank, a flocculation tank, an electro-catalytic oxidation tank, a pre-anoxic tank, a CASS tank and a disinfection tank for treatment. In the Fenton oxidation tank, the concentration of hydrogen peroxide is dynamically controlled. The application aims to avoid the problems that cyanide ions in the nereistoxin pesticide wastewater cannot be completely reacted and a large amount of harmful ammonia gas is released, improve the removal capacity of nereistoxin in the agricultural wastewater treatment, and improve the biodegradability of the nereistoxin pesticide wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a processing technology of nereistoxin pesticide wastewater. BACKGROUND

[0002] Nereistoxin pesticide is a modern synthetic insecticide, and nereistoxin pesticide wastewater has large quantity, high pollutant concentration and great toxicity. The purpose of treating nereistoxin pesticide wastewater is to reduce the pollutant concentration in the wastewater as much as possible and achieve harmlessness.

[0003] Fenton oxidation, as a commonly used advanced oxidation technology, can destroy organic matter in the dark, and has the advantages of simple operation process, easy reaction, low running cost, and less equipment investment. Fenton oxidation usually involves adding a fixed amount of hydrogen peroxide into a Fenton oxidation tank to generate Fenton oxidation reaction. However, the water quality and quantity of nereistoxin pesticide wastewater are extremely unstable, and it is difficult to timely sense the Fenton oxidation condition of the Fenton oxidation tank and dynamically control the hydrogen peroxide concentration in the Fenton oxidation tank. Therefore, the nereistoxin in the nereistoxin pesticide wastewater cannot be completely removed, and harmful ammonia gas is released. SUMMARY

[0004] In view of the above, it is necessary to provide a processing technology of nereistoxin pesticide wastewater to solve the above problems.

[0005] One embodiment of the present application provides a processing technology of nereistoxin pesticide wastewater, which comprises:

[0006] S1: filtering large particles and impurities in the nereistoxin pesticide wastewater in a filter tank;

[0007] S2: feeding the wastewater treated in the filter tank into a pH adjusting tank;

[0008] S3: feeding the wastewater treated in the pH adjusting tank into a Fenton oxidation tank, adding ferrous sulfate solution and hydrogen peroxide solution, and dynamically controlling the concentration of hydrogen peroxide in the Fenton oxidation tank, and the specific process is as follows:

[0009] S301: dividing the Fenton oxidation tank into a preset number of regions and numbering, collecting thermal imaging images of each region at each time, and obtaining the carbon dioxide concentration and ammonia concentration of the Fenton oxidation tank at each time;

[0010] S302: segmenting the thermal imaging images of each region of the Fenton oxidation tank at each time except the first region to obtain a plurality of superpixel blocks; analyzing the temperature distribution characteristics of each pixel block in each region, combining the temperature distribution difference of adjacent regions, and obtaining the thermal uniformity index of each region at each time; wherein the first region is the region closest to the water inlet of the Fenton oxidation tank.

[0011] S303: comparing the carbon dioxide concentration values of each region with the first region in the Fenton oxidation tank at each time, combining the thermal uniformity index of each region to obtain the oxidation reaction intensity of each region at each time; analyzing the trend of the oxidation reaction intensity of all regions at each time, combining the ammonia concentration values of all regions at each time to obtain the oxidant dosage index of the Fenton oxidation tank at each time;

[0012] S304: adjusting the amount of oxidant already added at each time according to the difference between the oxidant dosage coefficient at each time and the previous time;

[0013] S4: feeding the wastewater treated by the Fenton oxidation tank into the flocculation tank, adding sodium hydroxide and flocculants to form flocculation body precipitation;

[0014] S5: feeding the clarified sandworm toxin pesticide wastewater in the upper layer of the flocculation tank into the electro-catalytic oxidation tank, the pre-anoxic tank, the CASS tank and the disinfection tank in turn for treatment.

[0015] In S2, the pH value of the pH adjusting tank is 3-5.

[0016] In S3, the residence time of the wastewater in the Fenton oxidation tank is 60-90 min.

[0017] The specific process of obtaining the thermal uniformity index of each region at each time is as follows:

[0018] Based on the temperature mean value of all pixel points in each superpixel block, classify the superpixel blocks of each region at each time to obtain a plurality of superpixel block categories;

[0019] Calculate the average Euclidean distance between each superpixel block category and the center pixel of all other superpixel block categories as the temperature distribution distance of each superpixel block category;

[0020] According to the temperature distribution difference of all pixels in the thermal image of adjacent regions at each time, combined with the negative correlation mapping result of the temperature distribution distance of each superpixel block category of each region, obtain the thermal uniformity index of each region at each time.

[0021] The specific process of obtaining the oxidation reaction intensity of each region at each time is as follows:

[0022] Obtain the ratio of the carbon dioxide concentration values of the remaining regions of the Fenton oxidation tank to the first region at each time; the product of the ratio and the thermal uniformity index is the oxidation reaction intensity of the remaining regions of the Fenton oxidation tank at each time.

[0023] The specific process of obtaining the oxidant dosage index of the Fenton oxidation tank at each time includes:

[0024] Fitting the intensity of the oxidation reaction of all regions of the Fenton oxidation tank except the first region at each time, the negative correlation of the slope of the obtained fitting straight line is mapped as the oxidation reaction attenuation degree of the Fenton oxidation tank at each time;

[0025] Taking the average of the ammonia gas concentration values of all regions of the Fenton oxidation tank at each time as the ammonia gas emission value of the Fenton oxidation tank at each time;

[0026] Taking the result of the fusion of the oxidation reaction attenuation degree and the ammonia gas emission value of the Fenton oxidation tank at all times as the oxidant addition coefficient of the Fenton oxidation tank.

[0027] The adjustment of the added amount of the oxidant at each time is specifically:

[0028] The adjusted oxidant addition replenishment value at the current time is denoted as r, and its formula form is: Wherein, R is the added amount of the oxidant at the current time, E' is the oxidant addition coefficient at the previous time, and E is the oxidant addition coefficient at the current time.

[0029] Wherein, the pH value of the flocculation tank is adjusted to 8-9 by adding sodium hydroxide; the flocculant is polyacrylamide or polyaluminum.

[0030] Wherein, the hydraulic retention time in the pre-anoxic tank is 8-10h, the sludge concentration is 2000-6000mg / L, and the dissolved oxygen is controlled at 0.5mg / L.

[0031] Wherein, the residence time of the nereidid toxin pesticide wastewater in the aeration stage of the main reaction zone of the CASS tank is 8-10h, the residence time in the sedimentation stage is 1-1.5h, the residence time in the decanting stage is 1-1.5h, and the residence time in the idle stage is 0.5-1h; the sludge concentration is 4000-6000mg / L.

[0032] The present application has at least the following beneficial effects:

[0033] 1. The present application combines Fenton oxidation, three-dimensional electro-catalytic oxidation and biochemical treatment organically, three-dimensional electro-catalytic oxidation generates intermediate products with strong oxidation ability through anode oxidation or anode reaction, or other intermediate reactions occur in addition to anode reaction. With the synergistic effect of catalysts, these intermediate products can effectively oxidize the treated pollutants, and finally realize the degradation of the pollutants. This method can efficiently degrade the organic matter in pesticide wastewater, reduce the toxicity of water body, and will not produce secondary pollution. The removal rate of organic pollutants in nereidid toxin pesticide wastewater is improved, and the energy consumption is reduced.

[0034] 2. The application constructs the oxidation reaction intensity according to the temperature distribution and the carbon dioxide concentration of the chemical reaction in the Fenton oxidation tank, and has beneficial effects in that the Fenton reaction and the oxidation reaction in the Fenton oxidation tank are both exothermic reactions, the oxidation reaction intensity can exclude the interference of the Fenton reaction heat release, reflect the reaction intensity of the nereistoxin pesticide wastewater oxidation reaction, and improve the accuracy of subsequent hydrogen peroxide concentration evaluation.

[0035] 3. The application analyzes the attenuation degree and the ammonia gas dissipation degree of the oxidation reaction in the Fenton oxidation tank, timely senses the Fenton oxidation condition of the Fenton reaction tank, dynamically controls the hydrogen peroxide concentration in the Fenton reaction tank by supplementing and adding the oxidant, avoids the problem that the cyanide ion reaction in the nereistoxin pesticide wastewater is not complete and harmful ammonia gas is released, improves the removal capacity of the nereistoxin in the agricultural wastewater, and reduces the ammonia gas dissipation in the Fenton oxidation tank. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A flowchart of a nereistoxin pesticide wastewater treatment process provided by the application is provided.

[0037] Figure 2 A Fenton oxidation tank schematic diagram provided by the application is provided.

[0038] Figure 3 A specific flowchart of controlling the hydrogen peroxide concentration in the Fenton oxidation tank provided by the application is provided. DETAILED DESCRIPTION

[0039] In the description of the embodiments of the application, the words “exemplary”, “or”, “for example” are used to mean as an example, instance, or illustration. Any embodiment or design solution described as “exemplary” or “for example” in the embodiments of the application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of “exemplary”, “or”, “for example” is intended to present relevant concepts in a specific manner.

[0040] 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 the application belongs. The terminology used in the specification of the application is only for the purpose of describing specific embodiments and is not intended to limit the application.

[0041] In addition, it should be pointed out that the terms “first”, “second” in the application and its drawings are used to distinguish similar objects, and are not used to describe a specific order or sequence. The method disclosed in the embodiments of the application or the method shown in the flowchart includes one or more steps for implementing the method, and the execution order of the steps can be interchanged with each other without departing from the scope of the application, and some steps can also be deleted.

[0042] 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 application belongs.

[0043] Embodiment 1

[0044] The embodiment 1 of the present application provides a processing technology for nereid toxin pesticide wastewater, which is applied to the technical field of wastewater treatment and refers to the accompanying drawings Figure 1 The processing technology comprises the following steps.

[0045] S1: The nereid toxin pesticide wastewater is first subjected to a filter tank to remove impurities in the wastewater, and specifically, activated carbon is arranged in the filter tank to filter large particles and impurities in the nereid toxin pesticide wastewater, so as to avoid the interference of the large particles and impurities on the subsequent wastewater treatment and improve the treatment efficiency.

[0046] S2: The nereid toxin pesticide wastewater treated by the filter tank is fed into a pH adjusting tank, a dilute sulfuric acid dosing tank is connected to the pH adjusting tank, the pH value of the wastewater is adjusted, and a reaction environment is provided for the subsequent Fenton reaction, wherein the pH adjusting tank adjusts the pH value of the nereid toxin pesticide wastewater to 3.

[0047] S3: The nereid toxin pesticide wastewater treated by the pH adjusting tank is fed into a Fenton oxidation tank, an 18% concentration ferrous sulfate solution tank is connected to the water inlet of the Fenton oxidation tank, and the dosage of ferrous sulfate solution is 6 kg per ton of wastewater, and a 30% concentration hydrogen peroxide tank is connected to 1 / 6 of the Fenton oxidation tank to dynamically control the concentration of hydrogen peroxide in the Fenton oxidation tank, and the residence time of the nereid toxin pesticide wastewater in the Fenton oxidation tank is 60 min. The purpose of the Fenton oxidation tank is to oxidize nereid toxins in the nereid toxin pesticide wastewater and to pre-oxidize a part of refractory and toxic organic compounds.

[0048] S301: The Fenton oxidation tank is evenly divided into a preset number of regions and numbered, and thermal imaging images at each time in each region are collected; the carbon dioxide concentration and the ammonia concentration of the Fenton oxidation tank at each time are obtained.

[0049] The Fenton oxidation tank is evenly divided into a preset number of regions according to the length from the water inlet to the water outlet, and the regions are numbered from small to large according to the distance from the water inlet. It should be noted that in the embodiment, the preset number is 6, and only ferrous sulfate as a catalyst is put into the first region, and hydrogen peroxide has not been put into the first region, and hydrogen peroxide has been put into the second to sixth regions, chemical reactions occur in the regions, and a schematic diagram of the Fenton oxidation tank is shown in Figure 2As shown, wherein 201 is a Fenton oxidation tank, 202 is a nereistoxin pesticide wastewater liquid surface, 203 is a ferrous sulfate solution adding port, 204 is a hydrogen peroxide solution adding port, 205 is a ferrous sulfate solution storage tank, 206 is a hydrogen peroxide storage tank, and 207 is a third region of the Fenton oxidation tank. An infrared imaging device and a fixed online gas concentration detector are placed directly above the center of each region. The infrared imaging device obtains thermal imaging of the nereistoxin pesticide wastewater in the region. The fixed online gas concentration detector specifically includes an ammonia gas concentration detector and a carbon dioxide concentration detector, which obtain carbon dioxide concentration data and ammonia gas concentration data generated in the Fenton oxidation tank. The infrared imaging device, the ammonia gas concentration detector, and the carbon dioxide concentration detector are synchronously collected, and the collection time interval is 30 seconds, and the collection time is 10 minutes. It should be noted that the collection time interval and the collection time can be adjusted by the implementer according to the actual situation.

[0050] S302: Segmenting the thermal imaging images of each region of the Fenton oxidation tank at each time except the first region to obtain a plurality of superpixel blocks; analyzing the temperature distribution characteristics of each pixel block in each region, and combining the temperature distribution differences of adjacent regions to obtain a thermal uniformity index of each region at each time.

[0051] In the Fenton oxidation tank, hydrogen peroxide as an oxidizing agent reacts with the catalyst ferrous sulfate to produce strong oxidizing hydroxyl radicals. The main components in the nereistoxin pesticide wastewater are sodium cyanide, sodium sulfite, sodium chloride, organic matter, and water. The hydroxyl radicals generated by the Fenton reaction can oxidize the cyanide ions in the nereistoxin pesticide wastewater and pre-oxidize a part of the difficult-to-degrade and toxic organic compounds, decomposing into final products N2 and CO2 and being discharged.

[0052] The higher the concentration of hydrogen peroxide in the Fenton oxidation tank, the more effective collisions of activated molecules in the nereistoxin pesticide wastewater, and the nereistoxin pesticide wastewater at each position in the Fenton oxidation tank can react, accelerating the oxidation reaction rate and providing the oxidation effect of cyanide and organic matter. At the same time, the chemical reactions in the Fenton oxidation tank are exothermic reactions, generating a large amount of heat. Therefore, the higher the concentration of hydrogen peroxide, the more intense the chemical reaction in the Fenton oxidation tank, and the higher the temperature of the nereistoxin pesticide wastewater and the higher the uniformity of the temperature distribution.

[0053] The present application takes the thermal image of any region in the 2-6 regions of the Fenton oxidation tank at any time as an example, and takes the thermal image as the input of the superpixel segmentation (simple linear iterative cluster, SLIC) algorithm. In the present embodiment, the number of superpixel blocks is set to 20, and the implementer can set it according to the actual situation. The output is each superpixel block of the thermal image, and the temperatures of the pixels in each superpixel are similar. The average temperature of all pixels in each superpixel block in the thermal image is calculated, and the average temperature of all superpixel blocks is taken as the input of the natural breaks algorithm. The superpixel blocks with different average temperatures are divided into K categories, and the superpixel blocks in each category have similar temperatures. In the present embodiment, K is 5, and the number of categories can be adjusted by the implementer according to the actual situation. The average Euclidean distance between each superpixel block category and the center pixel of the remaining superpixel block categories is calculated as the temperature distribution distance of each superpixel block category.

[0054] According to the temperature distribution difference of all pixels in the thermal image of the adjacent region at each time, combined with the negative correlation mapping result of the temperature distribution distance of each superpixel block category of each region, the thermal uniformity index of each region at each time is obtained. In the present embodiment, the temperature distribution difference of the thermal image of the i-th region and the i-1-th region at each time is denoted as A i , wherein the temperature distribution difference is measured by the difference of the average temperature; the temperature distribution distance of the k-th superpixel block category of the i-th region is denoted as D i,k , and the negative correlation mapping result is represented in the form of reciprocal, that is, the formula of the thermal uniformity index u i of the i-th region at each time is: , wherein K represents the number of superpixel block categories, and i>1.

[0055] It should be understood that the smaller the distance between the superpixel block categories, the more non-local the chemical reaction in the Fenton oxidation tank region, and the more active the collision of activated molecules in the nereis toxin pesticide wastewater. At the same time, the greater the temperature difference in the adjacent region, the more intense the chemical reaction in the Fenton oxidation tank region, and the more heat is released, and the greater the thermal uniformity index.

[0056] Thus, the thermal uniformity index of any region in the 2-6 regions of the Fenton oxidation tank at any time is obtained, which is used to reflect the temperature condition in the working process of the Fenton oxidation tank.

[0057] S303: comparing the carbon dioxide concentration values of each region in the Fenton oxidation tank with the first region at each time, combining the thermal uniformity index of each region, obtaining the oxidation reaction intensity of each region at each time; analyzing the trend of the oxidation reaction intensity of all regions at each time, combining the ammonia concentration values of all regions at each time, obtaining the oxidation agent addition index of the Fenton oxidation tank at each time.

[0058] There are mainly two types of chemical reactions in the Fenton oxidation tank, one is the Fenton reaction of hydrogen peroxide and ferrous sulfate, which produces strong oxidizing hydroxyl radicals, which is the basis for the second type of chemical reaction, and the other is the oxidation reaction of hydroxyl radicals or hydrogen peroxide and cyanide ions or organic matter in nereidid toxin pesticide wastewater, which mainly includes cyanide breaking reaction and organic matter degradation reaction, which can significantly reduce the cyanide content and organic matter content in nereidid toxin pesticide wastewater.

[0059] Both Fenton reaction and oxidation reaction are exothermic reactions, and pure Fenton reaction has a large thermal uniformity index, which cannot reflect the reaction intensity of the oxidation reaction of nereidid toxin pesticide wastewater in the Fenton oxidation tank. The cyanide breaking reaction and organic matter degradation reaction in the Fenton oxidation tank will release a large amount of carbon dioxide, based on this, the carbon dioxide concentration values of each region in the Fenton oxidation tank with the first region at each time are compared, and the thermal uniformity index of each region is combined to obtain the oxidation reaction intensity of each region at each time: obtaining the ratio of the carbon dioxide concentration values of the remaining regions in the Fenton oxidation tank to the first region at each time.

[0060] It should be understood that the greater the thermal uniformity index of each region in the Fenton oxidation tank, the more intense the chemical reaction in the Fenton oxidation tank region, and a large amount of heat is released, and the greater the difference between the carbon dioxide concentration in each region except the first region and the first region, the more intense the chemical reaction in the Fenton oxidation tank region releases a large amount of carbon dioxide, and the more intense the oxidation reaction in the Fenton oxidation tank, that is, the greater the oxidation reaction intensity.

[0061] When the hydrogen peroxide in the Fenton oxidation tank is sufficient, the cyanide ions can be oxidized to harmless nitrogen gas and discharged through the cyanide breaking reaction. When the hydrogen peroxide concentration in the Fenton oxidation tank is low, the hydrogen peroxide concentration in the region with a larger serial number is lower, resulting in a gradual decrease in oxidation reaction with increasing serial number.

[0062] The oxidation reaction intensity of each region of the Fenton oxidation tank except the first region at each time is obtained, and the oxidation reaction intensity sequence is sorted in ascending order of region number. The overall trend of the oxidation reaction intensity sequence is obtained to evaluate the oxidation reaction attenuation degree of the Fenton oxidation tank at each time. Specifically, the least square method is used to linearly fit the oxidation reaction intensity sequence, and the abscissa of the fitting straight line is the region number and the ordinate is the oxidation reaction intensity. Further, the slope L of the fitting straight line is obtained, and the oxidation reaction attenuation degree G of the Fenton oxidation tank at each time is obtained based on the slope. The oxidation reaction attenuation degree is negatively correlated with the slope, and the specific formula is G = exp(-L), where exp() represents the exponential function with the natural constant as the base number.

[0063] It should be understood that the greater the overall trend of the oxidation reaction intensity sequence, that is, the greater exp(-L), the greater the oxidation reaction attenuation degree of the region with a larger Fenton oxidation tank number.

[0064] In the Fenton oxidation tank, when the hydrogen peroxide concentration is low and the oxidation is insufficient, there are unoxidized ammonium ions in the nereistoxin pesticide wastewater. Due to the heat generated by the chemical reaction in the Fenton oxidation tank and the generation of bubbles, the ammonium ions are easily converted into harmful ammonia gas and escape, producing a foul odor near the Fenton oxidation tank, which is irritating to the respiratory tract and mucous membranes of humans.

[0065] In this embodiment, the average of the ammonia gas concentration values of all regions of the Fenton oxidation tank at each time is taken as the ammonia gas escape value of the Fenton oxidation tank at each time. The result of fusing the oxidation reaction attenuation degree of the Fenton oxidation tank at all times with the ammonia gas escape value is taken as the oxidant dosage coefficient of the Fenton oxidation tank. The product of the oxidation attenuation degree and the ammonia gas escape value at each time is calculated as the fusion result, and the cumulative sum of the products obtained at the current time and the previous preset number of times is calculated and normalized as the oxidant dosage coefficient of the Fenton oxidation tank. In this embodiment, the preset number is 19, and the normalization method uses the sigmoid function. The implementer can adjust it according to the actual situation.

[0066] It should be understood that the greater the oxidation reaction attenuation degree, the greater the oxidation reaction attenuation of the Fenton oxidation tank with increasing sequence number, and the higher the ammonia gas escape value, the more ammonium ions in the nereistoxin pesticide wastewater are converted into ammonia gas that escapes. At this time, more oxidant hydrogen peroxide should be added to completely oxidize the cyanide ions and ammonium ions in the nereistoxin pesticide wastewater to produce harmless nitrogen gas, and the oxidant dosage coefficient is greater.

[0067] S304: Adjust the amount of oxidant added at each time point based on the difference between the oxidant addition coefficient at each time point and the previous time point.

[0068] The higher the oxidant dosage coefficient, the greater the amount of hydrogen peroxide should be added to increase the concentration of hydrogen peroxide in the wastewater from nereistoxin-based pesticides. This embodiment uses the following formula to obtain the adjusted oxidant dosage supplement value *r* at the current moment: Where R is the amount of oxidant added at the current moment, E′ is the oxidant addition coefficient at the previous moment, and E is the oxidant addition coefficient at the current moment. The higher the value, the less likely the added hydrogen peroxide in the Fenton oxidation tank is to support the oxidation reaction and completely oxidize the cyanide and ammonium ions in the nereistoxin-type pesticide wastewater to produce harmless nitrogen gas. Therefore, the more hydrogen peroxide should be added to the Fenton oxidation tank, the higher the oxidant addition value should be.

[0069] Adding an oxidant with a value of r to the Fenton oxidation tank and dynamically controlling the hydrogen peroxide concentration in the Fenton oxidation tank can improve the removal rate of nereistoxin in nereistoxin-type pesticide wastewater and reduce the emission of ammonia in the Fenton oxidation tank.

[0070] The specific flowchart for controlling the hydrogen peroxide concentration in the Fenton oxidation tank is as follows: Figure 3 As shown.

[0071] S4: The wastewater from nereistoxin-type pesticides treated in the Fenton oxidation tank is fed into the flocculation tank. First, the pH value is adjusted to 8 by adding sodium hydroxide. Then, a flocculant is added to the flocculation tank to form flocs and precipitate. The flocculant can be polyacrylamide.

[0072] S5: The clarified wastewater containing nereistoxin from the upper layer of the flocculation tank is pumped into the electrocatalytic oxidation tank via a lift pump. The electrocatalytic oxidation tank uses three-dimensional electrocatalytic oxidation technology, suitable for the treatment of high COD wastewater. The generated strong oxidizing substances can oxidize and degrade almost all organic matter into short-chain molecules. The electrocatalytic oxidation tank uses a BBD (boron-doped diamond) electrode with titanium as the substrate as the anode and a stainless steel plate as the cathode. The initial pH value is 7, and the current density is set to 60 mA / cm². 2 The residence time was set to 3 hours. When the BBD electrode was used as the anode, it was able to remove recalcitrant organic matter from the wastewater containing nereistoxin-based pesticides, improving its biodegradability and providing a guarantee for subsequent advanced treatment.

[0073] The nereistoxin pesticide wastewater treated by the electro-catalytic oxidation tank is fed into the pre-anoxic tank. The pre-anoxic tank provides an anoxic environment to promote the denitrifying bacteria in the sludge to reduce nitrate nitrogen to nitrogen gas, thereby removing nitrogen pollution. The hydraulic retention time is 8 h, the sludge concentration is 2000 mg / L, and the dissolved oxygen is controlled at 0.5 mg / L.

[0074] The nereistoxin pesticide wastewater treated by the pre-anoxic tank is fed into the CASS tank. The CASS tank has a removal effect on the pollutants in the nereistoxin pesticide wastewater, and also has good denitrification and phosphorus removal functions. Specifically, the main reaction zone of the CASS tank is divided into four stages: aeration, sedimentation, decanting, and idling, with residence times of 8 h, 1 h, 1 h, and 0.5 h, respectively. The sludge concentration is 4000 mg / L, and the excess sludge is partially returned to the pre-anoxic tank with a sludge return ratio of 20%.

[0075] The nereistoxin pesticide wastewater treated by the CASS tank is fed into the disinfection tank, which includes a disinfection zone and a clear water zone in sequence. The disinfection zone can be a UV disinfection tank or a sodium hypochlorite disinfection tank. The nereistoxin pesticide wastewater first passes through the disinfection zone with a residence time of 30 min, and then is discharged into the clear water zone. The clear water zone can be discharged into a receiving water body, completing the treatment process of the nereistoxin pesticide wastewater.

[0076] Embodiment 2

[0077] The embodiment 2 of the present application proposes a treatment process for nereistoxin pesticide wastewater, which is applied to the field of wastewater treatment technology, and refers to the accompanying drawings. Figure 1 The process comprises:

[0078] S1: The same steps as S1 in embodiment 1 are used to filter the nereistoxin agricultural wastewater.

[0079] S2: The same steps as S2 in embodiment 1 are used to adjust the pH of the wastewater treated by the filtration tank. The pH adjusting tank adjusts the pH of the nereistoxin pesticide wastewater to 5.

[0080] S3: The same steps as S3 in embodiment 1 are used to feed the wastewater treated by the pH adjusting tank into the Fenton oxidation tank. The dosage of ferrous sulfate solution is 6 kg per ton of wastewater, and the residence time of the wastewater in the Fenton oxidation tank is 60 min.

[0081] S4: The same steps as S4 in embodiment 1 are used to feed the wastewater treated by the Fenton oxidation tank into the flocculation tank. Sodium hydroxide is added to adjust the pH to 8, and a polymer aluminum flocculant is used.

[0082] S5: The clarified nereistoxin pesticide wastewater on the top of the flocculation tank is pumped into the electro-catalytic oxidation tank by a lifting pump. The initial pH is 7, and the current density is set to 80 mA / cm2 , the residence time is set to 3h.

[0083] The nereid toxin pesticide wastewater treated by the electro-catalytic oxidation tank is fed into the pre-anoxic tank, the hydraulic retention time is 10h, the sludge concentration is 4000mg / L, and the dissolved oxygen is controlled at 0.5mg / L.

[0084] The nereid toxin pesticide wastewater treated by the pre-anoxic tank is fed into the CASS tank, the main reaction zone of the CASS tank is divided into aeration, sedimentation, decanting and idle stages, the residence times are 8h, 1.5h, 1.5h and 0.5h respectively, the sludge concentration is 4000mg / L, and the residual sludge is partially refluxed to the pre-anoxic tank, and the sludge reflux ratio is 25%.

[0085] The nereid toxin pesticide wastewater treated by the CASS tank is fed into the disinfection tank, the residence time is 30min, and then the water is discharged to the clean water area, which can be discharged into the receiving water body, thereby completing the treatment process of the nereid toxin pesticide wastewater.

[0086] Example 3

[0087] The embodiment 3 of the present application proposes a treatment process for nereid toxin pesticide wastewater, which is applied to the field of wastewater treatment technology, and refers to the accompanying drawings Figure 1 , the process comprises:

[0088] S1: the same steps as S1 in example 1 are adopted to filter the nereid toxin pesticide wastewater.

[0089] S2: the same steps as S2 in example 1 are adopted to adjust the pH of the wastewater treated by the filter tank.

[0090] S3: the same steps as S3 in example 1 are adopted to feed the wastewater treated by the pH adjustment tank into the Fenton oxidation tank, wherein the dosage of ferrous sulfate solution is 8kg per ton of wastewater, and the residence time of the wastewater in the Fenton oxidation tank is 90min.

[0091] S4: the same steps as S4 in example 1 are adopted to feed the wastewater treated by the Fenton oxidation tank into the flocculation tank, wherein sodium hydroxide is added to adjust the pH value to 9, and the flocculant is polyaluminum.

[0092] S5: the clarified nereid toxin pesticide wastewater on the top of the flocculation tank is pumped into the electro-catalytic oxidation tank by a lifting pump, the initial pH value is 9, the current density is set to 60mA / cm 2 , the residence time is set to 5h.

[0093] The nereistoxin pesticide wastewater treated by the electro-catalytic oxidation tank is fed into the pre-anoxic tank, wherein the hydraulic retention time is 10 h, the sludge concentration is 6000 mg / L, and the dissolved oxygen is controlled at 0.5 mg / L.

[0094] The nereistoxin pesticide wastewater treated by the pre-anoxic tank is fed into the CASS tank, and the main reaction zone of the CASS tank is divided into four stages of aeration, sedimentation, decanting and idling, the residence time is 10 h, 1.5 h, 1.5 h and 1 h respectively, the sludge concentration is 6000 mg / L, and the residual sludge is partially backflowed to the pre-anoxic tank, and the sludge backflow ratio is 40%.

[0095] The nereistoxin pesticide wastewater treated by the CASS tank is fed into the disinfection tank, the residence time is 40 min, and then the wastewater is discharged into the clean water area, and the clean water area can be discharged into a receiving water body, thereby completing the treatment process of the nereistoxin pesticide wastewater.

[0096] Finally, the treatment results of the nereistoxin pesticide wastewater with the hydrogen peroxide concentration in the Fenton oxidation tank controlled (Example) and without the hydrogen peroxide concentration in the Fenton oxidation tank controlled (Comparative Example) are tested, and the statistical results are shown in Table 1:

[0097] Table 1: Test results of Example and Comparative Example

[0098]

[0099]

[0100] The determination of the nereistoxin content adopts the silver nitrate titration method; the determination of the ammonia gas concentration adopts the sodium hypochlorite-salicylic acid spectrophotometry, and the ammonia gas concentration monitoring point is the highest concentration point at the edge of the Fenton oxidation tank, which are all the existing known technologies.

[0101] The computer program product of the present application can be a computer program implemented on one or more computers. The program instructions can be stored on a computer readable medium, such as a hard disk, CD-ROM, optical storage, or any other tangible medium. The program instructions can be downloaded from the Internet or another network. The program instructions can be embodied in a carrier wave traveling over the Internet or other network. The computer readable medium can be a machine readable storage device, a machine readable transmission device, or a combination of both. The computer readable medium can be a computer readable storage device, a computer readable transmission device, or a combination of both.

[0102] The above embodiments are only used to illustrate the technical solutions of the present application, not limit the technical solutions of the present application; although the technical solutions of the present application are described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A treatment process for wastewater from nereistoxin-based pesticides, characterized in that, The process comprises: S1: filtering large particles and impurities in the nereistoxin agricultural wastewater in a filter tank; S2: feeding the wastewater treated by the filter tank into a pH adjusting tank; S3: feeding the wastewater treated by the pH adjusting tank into a Fenton oxidation tank, adding ferrous sulfate solution and hydrogen peroxide solution, and dynamically controlling the concentration of hydrogen peroxide in the Fenton oxidation tank, and the specific process is as follows: S301: dividing the Fenton oxidation tank into a preset number of regions and numbering, collecting thermal imaging images of each region at each time; obtaining the carbon dioxide concentration and ammonia concentration of the Fenton oxidation tank at each time; S302: segmenting the thermal imaging images of each region of the Fenton oxidation tank at each time except the first region to obtain a plurality of superpixel blocks; analyzing the temperature distribution characteristics of each pixel block in each region, and combining the temperature distribution differences of adjacent regions to obtain a thermal uniformity index of each region at each time, including: based on the temperature mean value of all pixel points in each superpixel block, classifying the superpixel blocks of each region at each time to obtain a plurality of superpixel block categories; calculating the average Euclidean distance between each superpixel block category and the center pixel of all other superpixel block categories as the temperature distribution distance of each superpixel block category; according to the temperature distribution difference of all pixels in the thermal imaging images of adjacent regions at each time, combining the negative correlation mapping result of the temperature distribution distance of each superpixel block category to obtain the thermal uniformity index of each region at each time; wherein the first region is the region closest to the inlet of the Fenton oxidation tank; S303: compare the carbon dioxide concentration values of each region of the Fenton oxidation tank with the first region at each time, combine the thermal uniformity index of each region, obtain the oxidation reaction intensity of each region at each time; analyze the trend of the oxidation reaction intensity of all regions at each time, combine the ammonia concentration values of all regions at each time, obtain the oxidation agent addition index of the Fenton oxidation tank at each time; wherein, obtain the ratio of the carbon dioxide concentration values of the remaining regions of the Fenton oxidation tank except the first region to the first region at each time; the product of the ratio and the thermal uniformity index is used as the oxidation reaction intensity of the remaining regions of the Fenton oxidation tank at each time; the oxidation reaction intensity of all regions of the Fenton oxidation tank except the first region at each time is fitted, and the negative correlation of the slope of the obtained fitting straight line is mapped as the oxidation reaction attenuation degree of the Fenton oxidation tank at each time; the mean value of the ammonia concentration values of all regions of the Fenton oxidation tank at each time is used as the ammonia gas emission value of the Fenton oxidation tank at each time; the result of the fusion of the oxidation reaction attenuation degree and the ammonia gas emission value of the Fenton oxidation tank at all times is used as the oxidation agent addition coefficient of the Fenton oxidation tank; adjust the added amount of the oxidation agent at each time, specifically, record the adjusted oxidation agent addition value at the current time as r, and the formula is: wherein, R is the added amount of the oxidation agent at the current time, E ′ is the oxidation agent addition coefficient at the last time, and E is the oxidation agent addition coefficient at the current time; S304: adjusting the amount of oxidant added at each time according to the difference between the oxidant addition coefficient at each time and the oxidant addition coefficient at the previous time; S4: feeding the wastewater treated by the Fenton oxidation tank into a flocculation tank, adding sodium hydroxide and a flocculant to form a flocculation body precipitate; S5: feeding the clarified nereistoxin pesticide wastewater on the upper layer of the flocculation tank into an electro-catalytic oxidation tank, a pre-anoxic tank, a CASS tank, and a disinfection tank in sequence for treatment.

2. The process for treating nereistoxin pesticide wastewater according to claim 1, wherein The pH value of the pH adjusting tank in S2 is 3-5.

3. The process for treating nereistoxin pesticide wastewater according to claim 1, wherein the nereistoxin pesticide wastewater is treated by the process for treating nereistoxin pesticide wastewater according to claim 1. The residence time of the wastewater in the Fenton oxidation tank in S3 is 60-90 min.

4. The treatment process for wastewater from nereistoxin-based pesticides as described in claim 1, characterized in that, The pH value of the flocculation tank is adjusted to 8-9 by adding sodium hydroxide; the flocculant is polyacrylamide or polyaluminum.

5. The treatment process for wastewater from nereistoxin-based pesticides as described in claim 1, characterized in that, The hydraulic retention time in the pre-anoxic tank is 8-10 h, the sludge concentration is 2000-6000 mg / L, and the dissolved oxygen is controlled at 0.5 mg / L.

6. The process for treating nereistoxin pesticide wastewater according to claim 1, wherein the nereistoxin pesticide wastewater is a wastewater from a process for producing a nereistoxin pesticide. The nereistoxin pesticide wastewater stays in the aeration stage of the main reaction zone of the CASS tank for 8-10 h, stays in the sedimentation stage for 1-1.5 h, stays in the decanting stage for 1-1.5 h, and stays in the idle stage for 0.5-1 h; the sludge concentration is 4000-6000 mg / L.

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