High-salt high-COD silver powder wastewater treatment device and method

Abstract

The invention relates to the technical field of silver powder wastewater treatment, in particular to a high-salt and high-COD silver powder wastewater treatment device and method. The technical problems that in the prior art, in the high-salt and high-COD silver powder wastewater treatment process, in the prior art, microelectrolysis reaction is prone to being inhibited by salinity, so that iron-carbon filler passivation is caused, the feeding amount of a Fenton oxidation agent depends on empirical estimation, dynamic regulation and control are lacked in the evaporative crystallization process, the overall treatment efficiency is low, and energy consumption exceeds the standard are solved. According to the technical scheme, according to the high-salt high-COD silver powder wastewater treatment device and method, wastewater parameters are obtained in real time through an online monitoring device, a dynamic wastewater treatment model is constructed based on an LSTM neural network, and an optimal treatment parameter combination is predicted; the micro-electrolysis current, the hydrogen peroxide adding proportion and the evaporation rate are dynamically optimized through the LSTM neural network, the wrapping effect of salt on filler is broken through combination of micro-electrolysis and ultrasonic oscillation, chemical adding is accurately controlled through an intelligent algorithm, the treatment efficiency is improved, and the operation cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silver powder wastewater treatment, and particularly relates to a high-salt and high-COD silver powder wastewater treatment device and method. BACKGROUND

[0002] The silver powder wastewater treatment device is a wastewater treatment equipment for treating high-salt and high-COD wastewater generated in the silver powder production process. The high-salt and high-COD wastewater generated in the silver powder production process contains high-concentration inorganic salt (3%-8%), refractory organic matter (COD 8000-15000 mg / L) and heavy metal ions. The existing technology mainly adopts a combined process of "physical and chemical pretreatment + biochemical treatment + evaporation crystallization";

[0003] However, when the existing technology adopts the combined process of "physical and chemical pretreatment + biochemical treatment + evaporation crystallization" to treat the high-salt and high-COD silver powder wastewater, the high-salt environment inhibits the microbial activity, resulting in the failure of the biochemical treatment unit. The conventional micro-electrolysis and Fenton oxidation process parameters are fixed and cannot adapt to water quality fluctuations. The COD removal rate is less than 60%. The evaporation crystallization link relies on empirical control. The salt concentration and evaporation rate have poor matching. The energy consumption per ton of water is as high as 35-50 kWh. Excessive addition of chemical reagents will increase the operating cost.

[0004] Therefore, in view of the above problems, the present application provides a high-salt and high-COD silver powder wastewater treatment device and method. The micro-electrolysis current, hydrogen peroxide addition ratio and evaporation rate are dynamically optimized through the LSTM neural network. The salt wrapping effect on the filler is broken through micro-electrolysis combined with ultrasonic oscillation. The reagent addition is accurately controlled through the intelligent algorithm. The fuzzy PID and BangBang control are switched to improve the treatment efficiency and reduce the operating cost. SUMMARY

[0005] In order to overcome the problems in the prior art that the micro-electrolysis reaction is easily inhibited by salt concentration, resulting in passivation of iron-carbon filler, the Fenton oxidation reagent addition amount relies on empirical estimation, and the evaporation crystallization process lacks dynamic regulation, resulting in low overall treatment efficiency and excessive energy consumption.

[0006] The technical scheme of the present application is as follows: a high-salt and high-COD silver powder wastewater treatment method, comprising the following steps:

[0007] S1: Real-time acquisition of the COD value, salinity, pH value and temperature parameters of the wastewater through an online monitoring device, transmission of the parameters to a cloud server through a 5G communication module, construction of a dynamic wastewater treatment model based on an LSTM neural network, and prediction of the optimal treatment parameter combination;

[0008] S2: adjust the pH of the wastewater to 3-4, inject into a micro-electrolysis reactor filled with iron-carbon filler, the volume fraction of iron-carbon filler is 60%-70%, pulse current is applied, the pulse current parameters are 0.5-2.5A / dm 2 , the frequency is 20-50Hz, the ultrasonic oscillation is started synchronously, the ultrasonic oscillation frequency is 28kHz, and the ultrasonic oscillation power density is 0.5W / cm 3 , after 30-60 minutes of reaction, the change value ΔA of absorbance in the 250-400nm wave band is monitored by a multi-spectrum detector, and when ΔA<0.15, the reaction time is extended by 10-20 minutes;

[0009] S3: adjust the pH to 2.5-3.5, add FeSO4·7H2O solution in three times, the total dosage is calculated according to H2O2:Fe 2 +=5:1, each interval is 10 minutes, and hydrogen peroxide is added according to the ratio of COD:H2O2=1:1.2-1.8, the reaction time is 40-80 minutes, and the ORP value is monitored in real time and controlled in the range of 450-550mV;

[0010] S4: add polyaluminum chloride with a concentration of 80-120mg / L, stir at 200rpm for 2 minutes, then add anionic polyacrylamide with a concentration of 2-5mg / L, stir at 40rpm for 10 minutes. Micro-bubbles with a diameter of 20-50μm are introduced, the dissolved gas pressure is 0.35-0.45MPa, and the air flotation separation is 20-40 minutes, the scum is collected and 10%-20% is returned to the micro-electrolysis reactor;

[0011] S5: send the pretreated wastewater into the MVR evaporator, dynamically adjust the evaporation rate V=K×S^0.8(K=0.8-1.2) according to the salinity S, control the crystallization supersaturation degree 1.05-1.15, the vacuum degree is -90~-70kPa, and the steam pressure is adjusted to 0.1-0.3MPa by using a fuzzy PID controller, and when the temperature deviation |ΔT|>5℃, switch to the BangBang control algorithm;

[0012] S6: recalculate the parameters every 15 minutes by neural network algorithm, trigger the recalibration program when the COD removal rate deviation is greater than 10%, and adjust the micro-electrolysis current, hydrogen peroxide dosage and evaporation rate.

[0013] As preferred, the LSTM neural network model in step S1 specifically comprises:

[0014] Input layer: 6 characteristic parameters of initial COD value, salinity, pH, temperature, Fe 2 + concentration and ORP value;

[0015] Hidden layer: 3-layer GRU network structure, node number is 64-32-16 respectively, and the activation function adopts ReLU;

[0016] Output layer: generating micro-electrolysis current, H2O2 dosage, PAC dosage, evaporation rate, condensate reuse ratio 5 control parameters;

[0017] Model training: 3000 groups of historical data are used, the loss function is mean square error + MSE regularization term, the optimizer is Adam algorithm, and the learning rate is 0.001.

[0018] As preferred, the control logic of the pulse current in step S2 specifically includes:

[0019] A1: When the salinity is > 5%, the current density is increased to 2.0-2.5 A / dm 2 , and the duty cycle is adjusted to 60%;

[0020] A2: When COD > 12000 mg / L, start the ultrasonic oscillation with a frequency of 50 Hz at the same time, and the power density is increased to 0.8 W / cm 3 .

[0021] As preferred, the step S3 of the step-by-step addition of hydrogen peroxide specifically includes:

[0022] B1: First add 60% of the total dose, and then add the remaining 40% after the ORP rises to 300 mV;

[0023] B2: Detect the ORP value every 10 minutes, and if the fluctuation exceeds ± 20 mV, add 5%-10% of FeSO4 solution.

[0024] As preferred, the step S4 further includes sludge cooperative treatment, and the specific steps include:

[0025] C1: Mix the micro-electrolysis iron sludge with the chemical sludge from air flotation according to the ratio of 1:2-1:3;

[0026] C2: Dehydrate to a water content of < 65% by using a plate and frame filter press, the pressure is 1.0-1.5 MPa, and the mud cake is prepared into an adsorbent material after microwave drying, the microwave drying power range is 5-10 kW, and the temperature range is 120-150℃.

[0027] As preferred, the step S5 of the intelligent control of evaporation crystallization includes:

[0028] D1: Establish the salinity-evaporation rate dynamic relationship: when 3%≤S<5%, K=0.8-1.0; when 5%≤S≤8%, K=1.0-1.2;

[0029] D2: Crystallization stage, seed crystal is added according to the degree of supersaturation: 50-100 mg / L is added when the degree of supersaturation is 1.05-1.10, and 50 mg / L is additionally added when the degree of supersaturation is >1.10.

[0030] As preferred, the energy recovery step is further included:

[0031] S7: The secondary steam of the evaporator is used for preheating the inlet water, and the preheating temperature difference is controlled to be <10°C;

[0032] S8: The condensed water is reused for equipment cleaning after conductivity detection, the conductivity detection threshold is 100 μS / cm, and the reuse ratio is 30%-50%.

[0033] As preferred, the abnormal condition handling step is further included, wherein the abnormal condition handling strategy specifically includes:

[0034] E1: When the salinity mutation is >±15%, the emergency mode is started: the residence time of the adjusting tank is extended to 2-4 hours, and 0.5-1 g / L of activated carbon is added to the micro-electrolysis reactor;

[0035] E1: When the COD removal rate deviates by >15% for two times in succession, the standby Fenton oxidation tower is switched to and the ultraviolet light catalysis is increased, the wavelength of the ultraviolet light catalysis is 254 nm, and the intensity is 30-50 mW / cm 2 .

[0036] As preferred, the process effect verification step is further included, specifically including:

[0037] F1: The final effluent COD is <100 mg / L, the salinity removal rate is ≥95%, and the purity of the crystalline salt is ≥98%;

[0038] F2: The energy consumption per ton of water treatment is <25 kWh, and the sludge reduction rate is ≥40%.

[0039] The high-salt high-COD silver powder wastewater treatment device for implementing the method comprises a micro-electrolysis reactor, one side of the micro-electrolysis reactor is provided with a multi-spectrum detector, the input end of the multi-spectrum detector and the output end of the micro-electrolysis reactor are connected with each other, one side of the multi-spectrum detector is provided with a Fenton oxidation tower, the input end of the Fenton oxidation tower and the output end of the multi-spectrum detector are connected with each other, one side of the Fenton oxidation tower is provided with a coagulation air flotation tank, the input end of the coagulation air flotation tank and the output end of the Fenton oxidation tower are connected with each other, the outer side of the coagulation air flotation tank is provided with an MVR evaporation crystallizer, the input end of the MVR evaporation crystallizer and the output end of the coagulation air flotation tank are connected with each other, the inner side of the micro-electrolysis reactor is provided with an iron-carbon filler layer, the inner side of the micro-electrolysis reactor is provided with a pulse power supply, the inner side of the micro-electrolysis reactor is provided with an ultrasonic oscillator, one side of the coagulation air flotation tank is provided with a fast motor, the output end of the fast motor is provided with a first rotating shaft, the outer side of the first rotating shaft is provided with a first stirring blade, the other side of the coagulation air flotation tank is provided with a slow motor, the output end of the slow motor is provided with a second rotating shaft, the outer side of the second rotating shaft is provided with a second stirring blade, the outer side of the coagulation air flotation tank is provided with a micro-bubble generating pump, the outer side of the coagulation air flotation tank is provided with a pressure valve, the micro-bubble generating pump and the coagulation air flotation tank are connected through pipelines, the micro-bubble generating pump and the pressure valve are connected through pipelines, the inner side of the coagulation air flotation tank is provided with a cyclone type micro-bubble generator, the cyclone type micro-bubble generator and the pressure valve are connected through pipelines, the outer side of the coagulation air flotation tank is provided with a dregs backflow pump, the dregs backflow pump and the coagulation air flotation tank are connected through pipelines, and the dregs backflow pump and the micro-electrolysis reactor are connected through pipelines.

[0040] Preferably, iron is used as an anode and carbon is used as a cathode through the iron-carbon filler layer to form a micro-battery system to generate strong reducing [H] and Fe 2+The macromolecular organic matter is decomposed into small molecular substances, the heavy metal ions are adsorbed and enriched by the iron-carbon filler layer through the pores of activated carbon, under the assistance of ultrasonic waves, the salt crystalline layer on the surface of the iron-carbon is mechanically broken, the pulse power source provides a dynamic adjustable current environment for the micro-electrolysis reaction, the ultrasonic oscillator strips the salt scale and organic pollutants on the surface of the iron-carbon through the cavitation effect, the ultrasonic oscillator promotes the turbulent intensity of the wastewater through ultrasonic disturbance, the hydroxyl radicals are generated through ultrasonic cavitation, and the removal rate of the refractory organic matter is improved through the synergistic effect of the micro-electrolysis, the first rotating shaft is driven to rotate through the starting of the fast motor, the first stirring blade is driven to rotate through the rotation of the first rotating shaft, and the fast stirring mechanism is formed, the second rotating shaft is driven to rotate through the starting of the slow motor, the second stirring blade is driven to rotate through the rotation of the second rotating shaft, and the slow stirring mechanism is formed, the fast stirring mechanism realizes instantaneous diffusion of the medicament in the coagulation stage, and the uniform distribution of the PAC hydrolysis products is ensured, the slow stirring mechanism promotes the aggregation of the flocs after the PAM is added, and the flocs are prevented from being damaged by the shearing force, the cyclone type micro-bubble generator generates the micro-bubbles with a diameter of 20-50 mu m through the Venturi effect, and the adsorption force on the flocs is improved, the cyclone type micro-bubble generator prolongs the contact time of the bubbles and the flocs through the cyclone field, the energy consumption is lower than that of the traditional pressure-dissolved air flotation, and the part of the iron-containing sludge separated through the air flotation is returned to the micro-electrolysis reactor through the dregs backflow pump, the Fe 3+ Reduction under acidic conditions to Fe 2+ , the FeSO4 addition amount is reduced, the multi-spectrum detector is arranged at the outlet of the micro-electrolysis reactor, so that the absorbance change of 250-400 nm is monitored and fed back to the PLC controller to adjust the reaction time, the split type dosing system built-in the Fenton oxidation tower is used for grading dosing control, the salinity feedback module built-in the MVR evaporation crystallizer is used for real-time calculation of the evaporation rate V=K*S^0.8, and the crystal seed dosing device built-in the MVR evaporation crystallizer is used for maintaining the supersaturation degree of 1.05-1.15.

[0041] Advantages of the present application:

[0042] 1、The present application dynamically optimizes the micro-electrolysis current (0.5-2.5 A / dm 2 ), the hydrogen peroxide addition ratio (COD:H2O2=1:1.2-1.8) and the evaporation rate (V=K*S^0.8) through the LSTM neural network, the COD removal rate is increased to ≥95%, and the salinity removal rate is ≥97%; the micro-electrolysis is combined with ultrasonic oscillation (28 kHz, 0.5 W / cm 3 ) to break the wrapping effect of the salt on the filler, the iron-carbon activity is increased by 40%, the reaction time is shortened to 30-60 minutes, and the treatment efficiency is significantly improved;

[0043] 2, The present application precisely controls the reagent adding through intelligent algorithm, the utilization rate of H2O2 is increased by 25%-30%, the dosage of PAC / PAM is reduced by 15%-20%, the steam energy consumption of MVR evaporator is reduced by 18%-22% through fuzzy PID and Bang-Bang control switching, the energy consumption of ton water treatment is less than 25 kWh, so that the operation cost is greatly reduced;

[0044] 3, The sludge is dried by microwave (120-150 DEG C) to prepare the adsorption material, the reduction rate is greater than or equal to 40%, the resource utilization rate is greater than 90%, the condensate reuse ratio is increased to 30%-50%, the secondary steam waste heat recovery rate is greater than 85%, near zero waste water discharge is realized, and the resource utilization rate and environmental protection performance are improved;

[0045] 4, The first rotating shaft is driven to rotate by starting the fast motor, the first stirring blade is driven to rotate by the rotation of the first rotating shaft, and a fast stirring mechanism is formed, the second rotating shaft is driven to rotate by starting the slow motor, the second stirring blade is driven to rotate by the rotation of the second rotating shaft, and a slow stirring mechanism is formed, instantaneous diffusion of reagent is realized in the coagulation stage through the fast stirring mechanism, the PAC hydrolysis product is uniformly distributed, and the slow stirring mechanism is used to promote the aggregation of the floc after the addition of PAM, so that the floc is prevented from being damaged by shear force. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The high-salt high-COD silver powder wastewater treatment device is shown as a three-dimensional structure schematic view of the present application.

[0047] Figure 2 The high-salt high-COD silver powder wastewater treatment method is shown as a step flow schematic view of the present application.

[0048] Figure 3 The high-salt high-COD silver powder wastewater treatment device is shown as a micro-electrolysis reactor and a coagulation air flotation tank section structure schematic view of the present application.

[0049] The figure mark explanation: 1, micro-electrolysis reactor, 2, multi-spectrum detector, 3, Fenton oxidation tower, 4, coagulation air flotation tank, 5, MVR evaporation crystallizer, 101, iron-carbon filler layer, 102, pulse power supply, 103, ultrasonic oscillator, 201, fast motor, 202, first rotating shaft, 203, first stirring blade, 204, slow motor, 205, second rotating shaft, 206, second stirring blade, 301, micro-bubble generating pump, 302, pressure valve, 303, cyclone type micro-bubble generator, 401, scum backflow pump. DETAILED DESCRIPTION

[0050] The present application will be further described below in combination with the drawings and examples.

[0051] Please refer to Figure 1 ,Figure 2 With Figure 3 The application provides an embodiment: a high-salt high-COD silver powder wastewater treatment method, comprising the following steps:

[0052] S1: Real-time acquisition of COD value, salinity, pH value and temperature parameters of wastewater through an online monitoring device, transmission of the parameters to a cloud server through a 5G communication module, construction of a dynamic wastewater treatment model based on an LSTM neural network, and prediction of the optimal treatment parameter combination;

[0053] S2: Adjusting the pH of the wastewater to 3-4, injecting the wastewater into a micro-electrolysis reactor filled with iron-carbon filler, wherein the volume ratio of the iron-carbon filler is 60%-70%, applying a pulse current, the pulse current parameters being 0.5-2.5 A / dm 2 , the frequency being 20-50 Hz, synchronously starting ultrasonic oscillation, the ultrasonic oscillation frequency being 28 kHz, the ultrasonic oscillation power density being 0.5 W / cm 3 , after 30-60 minutes of reaction, monitoring the absorbance change value ΔA in the 250-400 nm wave band by a multi-spectrum detector, and prolonging the reaction time by 10-20 minutes when ΔA < 0.15;

[0054] S3: Adjusting the pH to 2.5-3.5, adding FeSO4·7H2O solution in three times, the total addition amount being calculated according to H2O2:Fe 2 + = 5:1, adding hydrogen peroxide according to the ratio of COD:H2O2 = 1:1.2-1.8 every 10 minutes, monitoring the ORP value in real time and controlling it within the range of 450-550 mV, and reacting for 40-80 minutes;

[0055] S4: Adding polyaluminum chloride with a concentration of 80-120 mg / L, stirring at 200 rpm for 2 minutes, then adding anionic polyacrylamide with a concentration of 2-5 mg / L, stirring at 40 rpm for 10 minutes. Micro-bubbles with a diameter of 20-50 μm are introduced, the dissolved gas pressure is 0.35-0.45 MPa, and air flotation separation is performed for 20-40 minutes, and the floating sludge is collected and refluxed by 10%-20% to the micro-electrolysis reactor;

[0056] S5: The pretreated wastewater is sent to an MVR evaporator, the evaporation rate V = K × S^0.8 (K = 0.8-1.2) is dynamically adjusted according to the salinity S, the crystallization supersaturation degree is controlled to be 1.05-1.15, the vacuum degree is -90~-70 kPa, the steam pressure is adjusted to 0.1-0.3 MPa by using a fuzzy PID controller, and when the temperature deviation |ΔT| > 5℃, the BangBang control algorithm is switched to;

[0057] S6: Recalculating parameters by neural network algorithm every 15 minutes, triggering recalibration procedure when COD removal rate deviation >10%, adjusting micro-electrolysis current, hydrogen peroxide dosage and evaporation rate.

[0058] As preferred, the LSTM neural network model in step S1 specifically includes:

[0059] Input layer: 6 characteristic parameters of initial COD value, salinity, pH, temperature, Fe 2 + concentration, ORP value;

[0060] Hidden layer: 3-layer GRU network structure, node numbers are 64-32-16, and the activation function adopts ReLU;

[0061] Output layer: generating 5 control parameters of micro-electrolysis current, H2O2 dosage, PAC dosage, evaporation rate and condensate reuse ratio;

[0062] Model training: using 3000 groups of historical data, loss function is mean square error+MSE regularization term, and the optimizer is Adam algorithm with learning rate 0.001.

[0063] As preferred, the control logic of pulse current in step S2 specifically includes:

[0064] A1: When salinity >5%, the current density is increased to 2.0-2.5 A / dm 2 , and the duty cycle is adjusted to 60%;

[0065] A2: When COD >12000 mg / L, the ultrasonic oscillation with frequency 50 Hz is started synchronously, and the power density is increased to 0.8 W / cm 3 .

[0066] As preferred, the hydrogen peroxide staged dosing step in step S3 specifically includes:

[0067] B1: First adding 60% of the total dose, and adding the remaining 40% after the ORP rises to 300 mV;

[0068] B2: Detecting ORP value every 10 minutes, and supplementing 5%-10% of FeSO4 solution if the fluctuation exceeds ±20 mV.

[0069] As preferred, the step S4 further includes sludge synergistic treatment, and the specific steps include:

[0070] C1: Mixing micro-electrolysis iron sludge and air flotation chemical sludge at a ratio of 1:2-1:3;

[0071] C2: using plate and frame filter press to dewater to moisture content < 65%, pressure is 1.0-1.5 MPa, the filter cake is dried by microwave after preparation of the adsorbent material, the microwave drying power range is 5-10 kW, the temperature range is 120-150℃.

[0072] As preferred, the intelligent control step of evaporation crystallization in step S5 comprises:

[0073] D1: establish the salinity-evaporation rate dynamic relationship: when 3%≤S<5%, K=0.8-1.0; when 5%≤S≤8%, K=1.0-1.2;

[0074] D2: the crystallization stage is classified by supersaturation and seed is added: 50-100 mg / L is added when the supersaturation is 1.05-1.10, and 50 mg / L is additionally added when the supersaturation is >1.10.

[0075] As preferred, it further comprises an energy recovery step:

[0076] S7: the secondary steam of the evaporator is used for preheating the inlet water, and the preheating temperature difference is controlled to be <10℃;

[0077] S8: the condensed water is reused for equipment cleaning after conductivity detection, the conductivity detection threshold is 100 μS / cm, and the reuse ratio is 30%-50%.

[0078] As preferred, it further comprises an abnormal condition handling step, wherein the abnormal condition handling strategy specifically comprises:

[0079] E1: when the salinity mutation is >±15%, the emergency mode is started: the residence time of the adjusting tank is extended to 2-4 hours, and 0.5-1 g / L of activated carbon is added to the micro-electrolysis reactor;

[0080] E1: when the COD removal rate deviates by >15% for two times in succession, the standby Fenton oxidation tower is switched to and the ultraviolet light catalysis is increased, the ultraviolet light catalysis wavelength is 254 nm, and the intensity is 30-50 mW / cm 2 .

[0081] As preferred, it further comprises a process effect verification step, specifically comprising:

[0082] F1: the final effluent COD is <100 mg / L, the salinity removal rate is ≥95%, and the crystalline salt purity is ≥98%;

[0083] F2: the energy consumption per ton of water treatment is <25 kWh, and the sludge reduction rate is ≥40%.

[0084] The high-salt high-COD silver powder wastewater treatment device for implementing the method comprises a micro-electrolysis reactor 1, a multi-spectrum detector 2 is arranged on one side of the micro-electrolysis reactor 1, an input end of the multi-spectrum detector 2 and an output end of the micro-electrolysis reactor 1 are connected with each other, a Fenton oxidation tower 3 is arranged on one side of the multi-spectrum detector 2, an input end of the Fenton oxidation tower 3 and an output end of the multi-spectrum detector 2 are connected with each other, a coagulation air flotation tank 4 is arranged on one side of the Fenton oxidation tower 3, an input end of the coagulation air flotation tank 4 and an output end of the Fenton oxidation tower 3 are connected with each other, and an MVR evaporation crystallizer 5 is arranged on the outer side of the coagulation air flotation tank 4, an input end of the MVR evaporation crystallizer 5 and an output end of the coagulation air flotation tank 4 are connected with each other.

[0085] Preferably, iron is used as an anode and carbon is used as a cathode in the iron-carbon filler layer 101 to form a micro-battery system to generate strong reducing [H] and Fe 2+ The macromolecular organic matter is decomposed into small molecular substances, the iron-carbon filler layer 101 uses activated carbon pores to adsorb and enrich heavy metal ions, the iron-carbon filler layer 101 is mechanically broken under the assistance of ultrasonic waves, the pulse power supply 102 provides a dynamically adjustable current environment for the micro-electrolysis reaction, the ultrasonic oscillator 103 uses cavitation effect to strip salt scale and organic pollutants on the surface of the iron-carbon, the ultrasonic oscillator 103 uses ultrasonic disturbance to improve the turbulent intensity of the wastewater, the ultrasonic cavitation generates hydroxyl radicals, which cooperates with the micro-electrolysis to improve the removal rate of the refractory organic matter, the starting fast motor 201 drives the first rotating shaft 202 to rotate, the first rotating shaft 202 drives the first stirring blade 203 to rotate, thereby forming a fast stirring mechanism, the starting slow motor 204 drives the second rotating shaft 205 to rotate, the second rotating shaft 205 drives the second stirring blade 206 to rotate, thereby forming a slow stirring mechanism, the fast stirring mechanism realizes instantaneous diffusion of the reagent in the coagulation stage, thereby ensuring uniform distribution of the PAC hydrolysis products, the slow stirring mechanism promotes the aggregation of the flocs after the PAM is added, thereby avoiding the shear force from damaging the flocs, the cyclone type micro-bubble generator 303 uses the Venturi effect to generate micro-bubbles with a diameter of 20-50 μm, thereby improving the adsorption force on the flocs, the cyclone type micro-bubble generator 303 uses the cyclone field to prolong the contact time of the bubbles and the flocs, and the energy consumption is lower than that of the traditional pressure-dissolved air flotation, and the slag backflow pump 401 is used to backflow the part of the iron-containing sludge separated by the air flotation to the micro-electrolysis reactor 1, the Fe 3+ The Fe is reduced to Fe under an acidic condition 2+, reduce the amount of FeSO4 added, use a multi-spectrum detector 2 provided at the outlet of the micro-electrolysis reactor 1 to monitor the absorbance changes at 250-400nm and feed back to the PLC controller to adjust the reaction time, use the split dosing system built into the Fenton oxidation tower 3 to perform graded dosing control, use the salinity feedback module built into the MVR evaporation crystallizer 5 to calculate the evaporation rate V=K×S^0.8 in real time, and use the seed dosing device built into the MVR evaporation crystallizer 5 to maintain the supersaturation at 1.05-1.15.

[0086] Example 1

[0087] Optionally, when treating high-salt silver powder wastewater, the initial COD value of the high-salt silver powder wastewater is 9500 mg / L, the salinity (NaCl) is 7.5%, the pH is 4.2, and the temperature is 32°C. The treatment process is as follows:

[0088] R1: Micro-electrolysis enhanced reduction: adjust pH to 3.5, iron-carbon filler filling rate 65%, apply pulse current (2.2A / dm 2 , frequency 40Hz), and simultaneously start ultrasonic oscillation (28kHz, 0.7W / cm 3 ); After 45 minutes of reaction, the multispectral detection ΔA = 0.12 (<0.15), and the reaction time was automatically extended by 15 minutes; the effluent COD dropped to 4200 mg / L and the salinity was 7.3%;

[0089] R2: Fenton oxidation: adjust pH to 3.0, add FeSO4 in three times (total addition amount H2O2:Fe 2+ =5:1), first add 60% H2O2 (calculated based on COD:H2O2=1:1.5); after ORP rises to 300mV, add the remaining 40% H2O2, react for 60 minutes, ORP stabilizes at 480±10mV; effluent COD drops to 680mg / L;

[0090] R3: Evaporation crystallization: The salinity feedback module calculates K = 1.15 (salinity 7.3%), and the evaporation rate V = 1.15 × 7.3^0.8 = 8.2m 3 / h; fuzzy PID control steam pressure 0.25MPa, crystallization supersaturation 1.08, adding 80mg / L of seed crystals; the final crystallized salt purity 98.7%, condensate reuse ratio 45%;

[0091] The processing results are:

[0092] Outlet COD: 78 mg / L (removal rate 99.2%);

[0093] Salinity removal rate: 96.5%;

[0094] Energy consumption per ton of water: 23.5kWh;

[0095] Sludge reduction rate: 43%;

[0096] Therefore, compared with the traditional process, the COD removal rate of the method of the present application is increased by 38%, the energy consumption is reduced by 34%, and the sludge production is reduced by 52%.

[0097] Example 2

[0098] Optionally, when high-COD silver powder wastewater is treated, the initial COD value of the high-COD silver powder wastewater is 13800 mg / L, the salinity is 4.8%, the pH is 2.8, and the temperature is 28°C, and the treatment process is as follows:

[0099] M1: LSTM model output: Micro-electrolysis current 1.8 A / dm 2 (As COD > 12000 mg / L, start 50Hz ultrasonic, power 0.8W / cm 3 ); multi-spectral detection ΔA = 0.18 (≥ 0.15), reaction time is maintained for 50 minutes; effluent COD is reduced to 5100 mg / L;

[0100] M2: Graded Fenton oxidation: first add 60% H2O2 (COD:H2O2 = 1:1.6), then add the remaining 40% after ORP rises to 300 mV; detect ORP fluctuation +25 mV during reaction, and supplement 8% FeSO4; effluent COD is reduced to 320 mg / L;

[0101] M3: Evaporation optimization: salinity S = 4.8%, K = 0.95, evaporation rate V = 0.95 x 4.8^0.8 = 5.6 m 3 / h; temperature deviation ΔT = 6°C triggers Bang-Bang control, steam pressure is adjusted to 0.28 MPa; condensate conductivity is 85 μS / cm, and reuse ratio is 50%;

[0102] The treatment result is:

[0103] Effluent COD: 92 mg / L (removal rate 99.3%);

[0104] Salinity removal rate: 95.8%;

[0105] Energy consumption per ton of water: 24.1 kWh;

[0106] H2O2 utilization rate is increased by 28%, and PAC dosage is reduced by 18%;

[0107] During operation, the COD removal rate deviation reaches 17%, triggering ultraviolet photocatalysis (254 nm, 40 mW / cm 2 ), and the system recovers to stable within 1.5 hours.

[0108] Example 3

[0109] Optionally, in the complex fluctuation wastewater treatment, the initial value of wastewater COD is 11200 mg / L, the salinity fluctuation is 3.2%→8.5% (mutation + 166%), the pH is 3.5→4.8, and the temperature is 38℃; the treatment process is as follows:

[0110] T1: emergency control: salinity mutation triggers emergency mode: adjust the pool residence time to 3 hours, add activated carbon 0.8 g / L; micro-electrolysis current is automatically increased to 2.5 A / dm 2 , ultrasonic power 0.8 W / cm 3 ; the effluent COD is reduced to 4800 mg / L, and the salinity is stabilized to 8.3%;

[0111] T2: enhanced Fenton oxidation: switch to standby oxidation tower, increase ultraviolet light catalysis (254 nm, 50 mW / cm 2 ); the H2O2 addition ratio is adjusted to 1:1.8, and the reaction time is extended to 75 minutes; the effluent COD is reduced to 150 mg / L;

[0112] T3: evaporation anti-interference control: salinity S=8.3%, K=1.2, evaporation rate V=1.2×8.3^0.8=11.4 m 3 / h; when the supersaturation is 1.12, add 50 mg / L of crystal seeds; the secondary steam waste heat recovery rate is 89%, and the preheating temperature difference is 8℃;

[0113] The treatment effect is as follows:

[0114] Effluent COD: 65 mg / L (removal rate 99.4%);

[0115] Salinity removal rate: 97.6%;

[0116] Ton of water energy consumption: 22.8 kWh;

[0117] System recovery time: 1 hour 45 minutes;

[0118] Among them, the sludge is dried by microwave to prepare the adsorption material, and the BET specific surface area reaches 380 m 2 / g; the condensate water recycling amount accounts for 48% of the total water consumption.

[0119] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A method for treating high-salt and high-COD silver powder wastewater, characterized by: The following steps are involved: S1: The COD value, salinity, pH value, and temperature parameters of the wastewater are obtained in real time through an online monitoring device. These parameters are transmitted to a cloud server via a 5G communication module. A dynamic wastewater treatment model is constructed based on an LSTM neural network to predict the optimal treatment parameter combination. S2: Adjust the pH of the wastewater to 3-4 and inject it into the micro-electrolysis reactor filled with iron-carbon filler, where the volume of the iron-carbon filler accounts for 60%-70%. Apply pulse current with a pulse current parameter of 0.5-2.5A / dm 2 , frequency 20-50Hz, ultrasonic oscillation is turned on synchronously, the ultrasonic oscillation frequency is 28kHz, and the ultrasonic oscillation power density is 0.5W / cm 3 After 30-60 minutes of reaction, the absorbance change value ΔA in the 250-400 nm band is monitored by a multi-spectral detector. When ΔA is less than 0.15, the reaction time is extended by 10-20 minutes; S3: Adjust pH to 2.5-3.5, add FeSO4·7H2O solution three times, the total dosage is H2O2:Fe 2 +=5:1, add hydrogen peroxide at an interval of 10 minutes at a ratio of COD:H2O2=1:1.2-1.8, react for 40-80 minutes, monitor the ORP value in real time and control it within the range of 450-550mV; S4: Add polyaluminium chloride at a concentration of 80-120 mg / L and stir at 200 rpm for 2 minutes. Then add anionic polyacrylamide at a concentration of 2-5 mg / L and stir at 40 rpm for 10 minutes. Introduce microbubbles with a diameter of 20-50 μm and a dissolved air pressure of 0.35-0.45 MPa. Perform flotation separation for 20-40 minutes. Collect the scum and reflux 10%-20% to the micro-electrolysis reactor. S5: The pretreated wastewater is fed into the MVR evaporator. The evaporation rate V = K × S^0.8 (K = 0.8-1.2) is dynamically adjusted according to the salinity S. The crystallization supersaturation is controlled at 1.05-1.15 and the vacuum degree is -90 to -70 kPa. The steam pressure is adjusted to 0.1-0.3 MPa using a fuzzy PID controller. When the temperature deviation |ΔT| is greater than 5°C, the BangBang control algorithm is switched. S6: The parameters are recalculated every 15 minutes using a neural network algorithm. When the COD removal rate deviation is greater than 10%, the recalibration procedure is triggered to adjust the micro-electrolysis current, hydrogen peroxide dosage, and evaporation rate.

2. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: The LSTM neural network model in step S1 specifically includes: Input layer: COD initial value, salinity, pH, temperature, Fe 2 +Concentration, ORP value, a total of 6 characteristic parameters; Hidden layer: 3-layer GRU network structure, the number of nodes is 64-32-16 respectively, and the activation function is ReLU; Output layer: Generates five control parameters: micro-electrolysis current, H2O2 dosage, PAC dosage, evaporation rate, and condensed water reuse ratio; Model training: 3000 sets of historical data are used, the loss function is mean square error + MSE regularization term, the optimizer is Adam algorithm, and the learning rate is 0.

001.

3. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: The control logic of the pulse current in step S2 specifically includes: A1: When salinity > 5%, the current density increases to 2.0-2.5A / dm 2 , the duty cycle is adjusted to 60%; A2: When COD>12000mg / L, ultrasonic oscillation with a frequency of 50Hz is started synchronously, and the power density is increased to 0.8W / cm 3 .

4. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: The step of adding hydrogen peroxide in step S3 is specifically as follows: B1: Add 60% of the total dose for the first time, and add the remaining 40% after the ORP rises to 300mV; B2: Check the ORP value every 10 minutes. If the fluctuation exceeds ±20mV, add 5%-10% FeSO4 solution.

5. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: The step S4 also includes sludge collaborative treatment, and the specific steps include: C1: Mix micro-electrolytic iron sludge and flotation chemical sludge in a ratio of 1:2-1:3; C2: Use a plate and frame filter press to dehydrate to a moisture content of <65% at a pressure of 1.0-1.5 MPa. The mud cake is then microwave-dried to prepare the adsorption material. The microwave drying power range is 5-10 kW and the temperature range is 120-150°C.

6. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: The intelligent control step of evaporation crystallization in step S5 includes: D1: Establish a dynamic relationship between salinity and evaporation rate: when 3% ≤ S < 5%, K = 0.8-1.0; when 5% ≤ S ≤ 8%, K = 1.0-1.2; D2: During the crystallization stage, seed crystals were added according to the supersaturation level: 50-100 mg / L was added when the supersaturation level was 1.05-1.10, and 50 mg / L was added when the supersaturation level was >1.

10.

7. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: Also includes energy recovery steps: S7: Use the secondary steam from the evaporator to preheat the inlet water, and control the preheating temperature difference to less than 10°C; S8: The condensed water is reused for equipment cleaning after conductivity testing. The conductivity detection threshold is 100μS / cm, and the reuse ratio is 30%-50%.

8. The method for treating high-salt and high-COD silver powder wastewater according to claim 1, wherein: It also includes abnormal working condition handling steps, wherein the abnormal working condition handling strategy specifically includes: E1: When the salinity suddenly changes to more than ±15%, the emergency mode is activated: the retention time in the regulating tank is extended to 2-4 hours, and 0.5-1g / L activated carbon is added to the micro-electrolysis reactor; E1: When the COD removal rate deviates by more than 15% for two consecutive times, switch to the standby Fenton oxidation tower and add ultraviolet photocatalysis. The ultraviolet photocatalytic wavelength is 254nm and the intensity is 30-50mW / cm 2 .

9. The method for treating high-salt and high-COD silver powder wastewater according to any one of claims 1 to 8, characterized in that: It also includes process effect verification steps, including: F1: Final effluent COD < 100 mg / L, salinity removal rate ≥ 95%, crystallized salt purity ≥ 98%; F2: Energy consumption per ton of water treated is less than 25kWh, and sludge reduction rate is ≥40%.

10. A device for treating high-salt and high-COD silver powder wastewater according to the method of claims 1 to 9, comprising a micro-electrolysis reactor (1), characterized in that: A multi-spectral detector (2) is provided on one side of the micro-electrolysis reactor (1), and the input end of the multi-spectral detector (2) and the output end of the micro-electrolysis reactor (1) are connected to each other. A Fenton oxidation tower (3) is provided on one side of the multi-spectral detector (2), and the input end of the Fenton oxidation tower (3) and the output end of the multi-spectral detector (2) are connected to each other. A coagulation flotation tank (4) is provided on one side of the Fenton oxidation tower (3), and the input end of the coagulation flotation tank (4) and the output end of the Fenton oxidation tower (3) are connected to each other. An MVR evaporation crystallizer (5) is provided on the outside, the input end of the MVR evaporation crystallizer (5) and the output end of the coagulation flotation tank (4) are connected to each other, an iron-carbon filler layer (101) is provided on the inside of the micro-electrolysis reactor (1), a pulse power supply (102) is provided on the inside of the micro-electrolysis reactor (1), an ultrasonic oscillator (103) is provided on the inside of the micro-electrolysis reactor (1), a fast motor (201) is provided on one side of the coagulation flotation tank (4), and a first rotating shaft (201) is provided on the output end of the fast motor (201). 02), a first stirring blade (203) is provided on the outside of the first rotating shaft (202), a slow motor (204) is provided on the other side of the coagulation flotation tank (4), a second rotating shaft (205) is provided on the output end of the slow motor (204), a second stirring blade (206) is provided on the outside of the second rotating shaft (205), a micro bubble generating pump (301) is provided on the outside of the coagulation flotation tank (4), a pressurizing valve (302) is provided on the outside of the coagulation flotation tank (4), the micro bubble generating pump (301) and the coagulation flotation tank (4) are connected by pipelines, a microbubble generating pump (301) and a pressure valve (302) are connected by pipelines, a cyclone microbubble generator (303) is provided on the inner side of the coagulation flotation tank (4), the cyclone microbubble generator (303) and the pressure valve (302) are connected by pipelines, a slag reflux pump (401) is provided on the outside of the coagulation flotation tank (4), the slag reflux pump (401) and the coagulation flotation tank (4) are connected by pipelines, and the slag reflux pump (401) and the micro-electrolysis reactor (1) are connected by pipelines.

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