CN115448549B

CN115448549B - Zero emission treatment system and method

Info

Publication number: CN115448549B
Application number: CN202211291238.5A
Authority: CN
Inventors: 王立攀; 张建飞; 段晓辉; 李艳霞
Original assignee: Bestter Group Co ltd
Current assignee: Bestter Group Co ltd
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2023-06-30
Anticipated expiration: 2042-10-20
Also published as: CN115448549A

Abstract

The invention relates to a zero emission treatment system and a zero emission treatment method. The anode treatment unit performs physical and chemical precipitation on the anode wastewater, and the etching deplating treatment unit removes COD and metal ions in the etching deplating wastewater. The invention designs a treatment system with zero emission of heavy metal wastewater based on various design concepts of ladder treatment, heavy metal wastewater diversion treatment and unified desalting treatment, and the pretreatment of anode wastewater and etching deplating wastewater is respectively carried out, and the pretreatment is carried out, the pretreatment is combined after physical and chemical precipitation, and then the reduction and desalting are carried out, so that the quality of produced water reaches the ultra-pure water recycling requirement of the electronic industry, and the physicochemical index of the treated mixed salt meets the requirement of solid waste consignment qualification units.

Description

Zero emission treatment system and method

Technical Field

The invention relates to the technical field of wastewater treatment, in particular to a zero emission treatment system and method.

Background

Heavy metal wastewater in the electronic industry belongs to wastewater which is difficult to treat, because the wastewater contains anode wastewater and etching deplating wastewater, the fluctuation of water quality is obvious, the treatment system is required to have the capability of resisting the fluctuation of water quality, the deplating jig and defective products are removed, and the water quality is greatly influenced by the yield of products. The methods commonly used in the prior art today consist in treatment by means of ion exchange membranes, such as the following patents:

Chinese patent CN106086896B discloses a circuit board acid etching solution circulation regeneration system based on heavy metal waste water treatment, including etching jar, electrolysis trough, be arranged in storing etching waste liquid holding tank, regeneration etching solution allotment groove of etching solution in the etching jar, the electrolysis trough includes and separates through the ion exchange membrane and forms cathode tank and positive pole groove, etching waste liquid holding tank one end intercommunication etching jar, the other end intercommunication cathode tank, regeneration etching solution allotment groove is located the positive pole groove with the three in etching jar are linked together, still include exhaust-gas treatment equipment, this exhaust-gas treatment equipment is linked together respectively and is had cathode tank, positive pole tank, and this exhaust-gas treatment equipment is equipped with the spray set who has strong base liquid hydrojet, all switch on outside positive pole tank and cathode tank has the temperature controller who is used for controlling the temperature value in the electrolysis trough, this patent beneficial effect lies in: decoppering and environmental protection recycling are carried out from acidic copper-chloride-containing etching waste liquid, so that economic, social and environmental benefits are improved, equipment stability cost is low, the etching waste liquid is recycled on line, and zero emission is realized.

Chinese patent CN 105523668B discloses a method and apparatus for zero emission treatment of PCB ammonia nitrogen-containing wastewater, which is characterized by comprising the following steps: adjusting the pH value of etching water washing wastewater to 8-11, and after rough filtration and ultrafiltration, electrolyzing filtrate I by using an electrolysis system with the current density of 1-3 ADS by using electrodes with the electrode plate distance D less than or equal to 3CM, wherein the generated gas is absorbed by using alkaline etching solution; and treating the electrolyzed filtrate by an ultrafiltration system to obtain filtrate II, and recycling the filtrate II. The patent changes the local concentration of the electrolysis product between the electrode plates by adjusting the distance of the electrode plates, so that chlorine generated by the anode escapes in a gaseous state due to local over-concentration to realize ammonia nitrogen and Cl ^- Finally, the treated effluent meets the technical requirement of etching water washing, and the industrial reuse water is met to realize zero emission.

However, the two patents have no industrial application prospect, cannot be used for large-scale and large-flow industrial heavy metal wastewater treatment, and the heavy metal wastewater not only comprises etching deplating wastewater, but also comprises anode wastewater, and is characterized in that: the main components of the anode wastewater are copper and nickel, and nitrate radical, phosphorus, ammonia nitrogen and organic matters are carried; the etching deplating waste water has complex components and contains various metal ions (copper, nickel, chromium, manganese, aluminum and iron) and a large amount of organic matters and inorganic matters (nitrate radical and phosphorus). The PH of the inlet water of the two kinds of waste water is 2-3, and the waste water belongs to the water quality of meta-acid. The metal ion concentration and the organic matter content of the anode wastewater are lower than those of the etching deplating wastewater. For this reason, special zero-emission treatment equipment is required for heavy metal wastewater in the electronic industry.

Furthermore, there are differences in one aspect due to understanding to those skilled in the art; on the other hand, as the inventors studied numerous documents and patents while the present invention was made, the text is not limited to details and contents of all that are listed, but it is by no means the present invention does not have these prior art features, the present invention has all the prior art features, and the applicant remains in the background art to which the rights of the related prior art are added.

Disclosure of Invention

Aiming at the defects of the prior art, the technical scheme of the invention is to provide a zero emission treatment system, which comprises an anode treatment unit, an etching deplating treatment unit and a concentration unit, wherein the anode treatment unit is communicated with the concentration unit in a manner of regulating the pH value of anode wastewater to be treated and performing physical and chemical precipitation; the etching deplating treatment unit removes COD and metal ions in the etching deplating wastewater to be treated based on degradation organic matters, and carries out two-stage adjustment of pH value and physical and chemical precipitation; the concentration unit carries out desalination concentration on the treated anode wastewater and the etched plating-removal wastewater to obtain produced water and concentrated water, wherein the concentration unit comprises a medium-pressure concentration membrane component and a high-pressure concentration membrane component, the treated anode wastewater and the etched plating-removal wastewater are sent into the medium-pressure concentration membrane component to obtain first produced water and first concentrated water, and the high-pressure concentration membrane component carries out desalination concentration on the first concentrated water obtained by the medium-pressure concentration membrane component based on reverse osmosis membrane characteristics to obtain second produced water and second concentrated water. The invention designs a treatment system for zero emission of heavy metal wastewater based on various design concepts of ladder treatment, heavy metal wastewater diversion treatment and unified desalting treatment, and the pretreatment of anode wastewater and etching deplating wastewater is respectively carried out, and the pretreatment is carried out, the pretreatment is combined after physical and chemical precipitation, and then the reduction and desalting are carried out, so that the quality of produced water meets the requirement of reuse water, and the physicochemical index of the treated mixed salt meets the requirement of solid waste consignment qualification units.

According to a preferred embodiment, the anode treatment unit comprises a PH adjusting tank, a first materialized sedimentation tank and a PH callback tank, wherein the PH adjusting tank and the PH callback tank are respectively connected to the front end and the rear end of the first materialized sedimentation tank, so that the effluent of the anode treatment unit can be communicated to the concentration unit in a mode of combining with the effluent of the etching deplating treatment unit within a set PH range. The heavy metal ions in the anode wastewater mainly comprise nickel, and the concentration of the metal ions is far lower than that of the etching deplating wastewater. After passing through the first materialized sedimentation tank 102, the effluent from the anode treatment unit 1 and the effluent from the etching deplating treatment unit 2 are combined.

According to a preferred embodiment, the etching deplating treatment unit comprises a first-stage PH adjusting tank, a Fenton oxidation module, a second-stage PH adjusting tank and a second chemical precipitation tank which are operated separately but are sequentially communicated with each other, wherein the etching deplating wastewater flows to the first-stage PH adjusting tank for treatment, sequentially passes through the Fenton oxidation module, the second-stage PH adjusting tank and the second chemical precipitation tank, and is communicated to the concentration unit in a mode of combining with the effluent of the anode treatment unit. Fenton reaction is carried out by hydrogen peroxide and ferrous ion Fe under acidic condition ²⁺ Generates hydroxyl free radicals with strong oxidizing ability and initiates more other active oxygen to realize degradation of organic matters, and the oxidation process is chain reaction.

According to a preferred embodiment, the Fenton oxidation module has a Fenton reaction tower for removing refractory long-chain organics for COD reduction and a coagulation reaction tank for flocculating metal ions and precipitating discharge. Fenton oxidation reaction has the capability of removing COD which is difficult to degrade. The Fenton oxidation method is used as a pretreatment process before wastewater treatment, and the strong oxidation capacity of hydroxyl radicals is used for removing refractory long-chain organic matters, so that the influence of high COD on the membrane performance of a subsequent process system is avoided.

According to a preferred embodiment, the effluent of the anode treatment unit and the etching deplating treatment unit is discharged to a third chemical precipitation tank and sequentially enters the concentration unit through a high-density tank, an anaerobic and aerobic module and an activated carbon unit, wherein the activated carbon unit is filled with granular activated carbon for adsorbing free matters, microorganisms and heavy metal ions in wastewater and high-salt-resistant activated carbon for removing CODcr, chromaticity, colloid, heavy metals and SS.

According to a preferred embodiment, the anaerobic-aerobic module comprises an anaerobic tank positioned at the front section and an aerobic tank positioned at the rear section, heterotrophic bacteria in the anaerobic tank remove nitrogen and phosphorus in the wastewater through denitrification, the aerobic tank ammonifies protein and fat, and the wastewater after ammonification is oxidized through nitrification of autotrophic bacteria and is returned to the anaerobic tank through reflux control so as to further carry out harmless treatment on the wastewater. The anaerobic tank is mainly used for denitrification and dephosphorization; the aerobic tank is mainly used for removing organic matters in water. The anaerobic-aerobic module 6 can remove organic pollutants in the wastewater and also can remove nitrogen and phosphorus at the same time.

According to a preferred embodiment, the medium pressure concentration membrane module obtains a first produced water and a first concentrated water, the first concentrated water is sent to the high pressure concentration membrane module for desalination concentration to obtain a second produced water and a second concentrated water, wherein the first produced water and the second produced water are sent to a reverse osmosis membrane unit and solute and hydrosolvent in the produced water are separated in a two-stage separation mode so that the first produced water and the second produced water reach a reuse water standard, and the second concentrated water is sent to a crystallization unit. The pretreated qualified raw water enters a medium-pressure concentration membrane assembly 301 and a high-pressure concentration membrane assembly 302 which are arranged in a pressure container, water molecules and a very small amount of small molecular weight organic matters pass through a membrane layer, are concentrated through a collecting pipeline, and then are led to a water production pipe to be injected into a reverse osmosis water tank. Otherwise, the concentrated water is concentrated through the other group of collecting pipelines and then is led to a concentrated water discharge pipe to be discharged into a concentrated water tank. The reverse osmosis equipment can effectively remove dissolved salts, colloid, microorganism, organic matters and the like in the water

According to a preferred embodiment, the crystallization unit performs three-effect forced circulation mixed flow evaporation crystallization and rotary drum on the second concentrated water, and the second concentrated water is evaporated into mixed salt to be treated as solid waste, wherein condensed water generated in the evaporation process of the crystallization unit enters a condensed water pipeline to be cooled and then is discharged into the anaerobic-aerobic module.

The invention also relates to a zero emission treatment method, which comprises the following steps: the anode treatment unit is used for carrying out pH value adjustment and physical and chemical precipitation on the anode wastewater to be treated; removing COD and metal ions in the etching plating stripping wastewater to be treated based on degradation organic matters in an etching plating stripping treatment unit, and performing two-stage adjustment of pH value and physical and chemical precipitation; desalting and concentrating the treated anode wastewater and the treated etching deplating wastewater in a concentrating unit to obtain produced water and concentrated water, wherein the concentrating unit comprises a medium-pressure concentrating membrane component and a high-pressure concentrating membrane component, the treated anode wastewater and the treated etching deplating wastewater are sent into the medium-pressure concentrating membrane component to obtain first produced water and first concentrated water, and the high-pressure concentrating membrane component is used for desalting and concentrating the first concentrated water obtained by the medium-pressure concentrating membrane component based on reverse osmosis membrane characteristics to obtain second produced water and second concentrated water.

According to a preferred embodiment, the anode treatment unit comprises a PH adjusting tank, a first materialized sedimentation tank and a PH callback tank, wherein the PH adjusting tank and the PH callback tank are respectively connected to the front end and the rear end of the first materialized sedimentation tank, so that the effluent of the anode treatment unit can be communicated to the concentration unit in a mode of combining with the effluent of the etching deplating treatment unit within a set PH range.

The beneficial technical effects of the invention are as follows:

(1) The invention designs a treatment system with zero emission of heavy metal wastewater based on various design concepts of ladder treatment, heavy metal wastewater diversion treatment and unified desalting treatment, and the pretreatment of anode wastewater and etching deplating wastewater is respectively carried out, and the pretreatment is carried out, the pretreatment is combined after physical and chemical precipitation, and then the reduction and desalting are carried out, so that the quality of produced water meets the requirement of reuse water, and the physicochemical index of the treated mixed salt meets the requirement of solid waste consignment qualification units;

(2) According to the characteristics of low PH value, high metal ion concentration and high COD of etching deplating wastewater, the wastewater is firstly introduced into a Fenton oxidation device, hydroxyl radicals generated by ferrous iron and hydrogen peroxide are utilized to attack long-chain structures of refractory COD, and meanwhile, the removal effect of flocculation precipitation on metal ions is also achieved, so that the capability of removing organic matters and partial heavy metal ions is achieved, and meanwhile, the acid amount used for adjusting the PH value can be saved. The damage of calcium and magnesium ions to the sewage recycling membrane device is reduced, and the engineering investment cost is saved;

(3) The wastewater enters an activated carbon unit, suspended matters, colloid, humus, COD, organic matters, iron colloid and the like in the wastewater are removed further, the operation safety of a back-stage reverse osmosis device is improved, then a medium-pressure concentration membrane assembly and a high-pressure concentration membrane assembly are used for carrying out reduction treatment on the wastewater, and produced water enters a primary osmosis membrane module, a secondary osmosis membrane module and an ultrapure water module and is further desalted, so that the quality of the produced water meets the requirement of reuse water. Concentrated water enters a crystallization device and a rotary drum of the triple-effect evaporator, is evaporated into mixed salt and is used as solid waste to be entrusted with qualification unit treatment, condensed water generated in the evaporation process enters a condensate pipe for cooling and is discharged into an anaerobic-aerobic module for treatment.

Drawings

FIG. 1 is a schematic block diagram of a zero emission treatment system of the present invention;

FIG. 2 is a schematic block diagram of an anodic treatment unit according to a preferred embodiment of the invention;

FIG. 3 is a schematic block diagram of an etch deplating process unit in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic block diagram of a concentrating unit according to a preferred embodiment of the present invention;

FIG. 5 is a schematic structural view of the reaction column of the present invention.

List of reference numerals

1: an anode treatment unit; 2: an etching deplating processing unit; 3: a concentration unit; 4: a third physical sedimentation tank; 5: a high-density pool; 6: an anaerobic-aerobic module; 7: an activated carbon unit; 8: a reverse osmosis membrane unit; 9: a crystallization unit; 10: a reaction tower; 101: a PH adjusting tank; 102: a first materialized sedimentation tank; 103: PH callback pool; 201: a primary PH regulating tank; 202: a Fenton oxidation module; 203: a secondary PH regulating tank; 204: a second chemical sedimentation tank; 301: a medium pressure concentrating membrane module; 302: a high pressure concentrating membrane module; 801: a first-stage permeable membrane module; 802: a secondary osmotic membrane module; 1001: a barrier layer; 1002: water layer entering; 1003: a water outlet layer; 1004: a first pump; 1005: a cathode portion; 1006: an anode portion; 1007: an aeration section; 1008: an electric field introduction device; 1009: a second pump; 1010: the cavity is regulated.

Detailed Description

The following detailed description refers to the accompanying drawings.

In the invention, chinese definitions corresponding to each English abbreviation:

COD: chemical oxygen demand. The amount of the oxidizing substance to be oxidized in the water sample is measured chemically. Oxygen equivalent of substances (typically organic substances) that can be oxidized by strong oxidants in wastewater, wastewater treatment plant effluent and contaminated water.

CODcr: the potassium dichromate is used as an oxidant to measure the oxygen demand, the value of COD is measured by a potassium dichromate method, and partial factors influence the value of COD, so that CODcr is not equal to COD, the COD is theoretically larger than CODcr, and the CODcr represents COD in practical application.

MBR: the membrane bioreactor (Membrane Bioreactor) is a combination of efficient membrane separation technology and traditional activated sludge processes, and is capable of trapping almost all microorganisms within the bioreactor.

Example 1

The application relates to a zero emission treatment system, which comprises an anode treatment unit 1, an etching deplating treatment unit 2 and a concentration unit 3, wherein the anode treatment unit 1 is communicated with the concentration unit 3 in a manner of adjusting the pH value of anode wastewater to be treated and performing physical and chemical precipitation; the etching deplating treatment unit 2 removes COD and metal ions in the etching deplating wastewater to be treated based on degradation organic matters and carries out two-stage adjustment of pH value and physical and chemical precipitation; the concentration unit 3 performs desalination concentration on the treated anode wastewater and the etched plating-removal wastewater to obtain produced water and concentrated water, wherein the concentration unit 3 comprises a medium-pressure concentration membrane assembly 301 and a high-pressure concentration membrane assembly 302, the treated anode wastewater and the etched plating-removal wastewater are sent to the medium-pressure concentration membrane assembly 301 to obtain first produced water and first concentrated water, and the high-pressure concentration membrane assembly 302 performs desalination concentration on the first concentrated water obtained by the medium-pressure concentration membrane assembly 301 based on reverse osmosis membrane characteristics to obtain second produced water and second concentrated water. The effluent from the anodic treatment unit 1 and the etching deplating treatment unit 2 is combined and discharged into the concentration unit 3. The main components of the anode wastewater are copper and nickel, and nitrate radical, phosphorus, ammonia nitrogen and organic matters are carried; the etching deplating waste water has complex components and contains various metal ions (copper, nickel, chromium, manganese, aluminum and iron) and a large amount of organic matters and inorganic matters (nitrate radical and phosphorus). The PH of the water inlet of the two water streams is 2-3, and the water belongs to the water quality with meta-acid property. The concentration of metal ions and the content of organic matters in the anode wastewater are lower than those in the etching-plating-removal wastewater, so that COD and metal ions in the etching-plating-removal wastewater are removed, the load of a front-stage wastewater treatment facility can be reduced, and the capital investment and the later-stage operation cost are saved. Etching plating removal waste water is firstly collected in the first-stage PH regulating tank 201, and is sent to the Fenton oxidation module 202 according to the characteristics of low PH value, high metal ion concentration and high COD of the etching plating removal waste water, hydroxyl free radicals generated by ferrous iron and hydrogen peroxide are utilized to attack long-chain structures of refractory COD, and meanwhile, the metal ions are also subjected to flocculation precipitation removal, so that the capability of removing organic matters and partial heavy metal ions is achieved, and meanwhile, the acid quantity used for regulating the PH value can be saved. Because the concentration of heavy metal ions in the etching deplating wastewater is high, the second chemical sedimentation tank 204 in the wastewater treatment process is designed and utilized to remove the heavy metal ions in the wastewater, reduce the hardness of the wastewater and reduce the damage of calcium and magnesium ions to the wastewater recycling membrane device. The second physical and chemical precipitation tank 204 can be a conventional two-stage physical and chemical precipitation tank to save engineering investment cost.

The invention designs a treatment system for zero emission of heavy metal wastewater based on various design concepts of ladder treatment, heavy metal wastewater diversion treatment and unified desalting treatment, and the pretreatment of anode wastewater and etching deplating wastewater is respectively carried out, and the pretreatment is carried out, the pretreatment is combined after physical and chemical precipitation, and then the reduction and desalting are carried out, so that the quality of produced water meets the requirement of reuse water, and the physicochemical index of the treated mixed salt meets the requirement of solid waste consignment qualification units.

According to a preferred embodiment, the anode treatment unit 1 comprises a PH adjusting tank 101, a first materialized sedimentation tank 102 and a PH callback tank 103, wherein the PH adjusting tank 101 and the PH callback tank 103 are respectively connected to the front end and the rear end of the first materialized sedimentation tank 102, so that the effluent of the anode treatment unit 1 can be communicated to the concentration unit 3 in a mode of combining with the effluent of the etching deplating treatment unit 2 within a set PH range. The heavy metal ions in the anode wastewater mainly comprise nickel, and the concentration of the metal ions is far lower than that of the etching deplating wastewater. After passing through the first materialized sedimentation tank 102, the effluent from the anode treatment unit 1 and the effluent from the etching deplating treatment unit 2 are combined.

According to a preferred embodiment, the etching-stripping treatment unit 2 includes a primary PH adjusting tank 201, a Fenton oxidation module 202, a secondary PH adjusting tank 203 and a second chemical precipitation tank 204 which are operated separately from each other but are sequentially communicated with each other, and the etching-stripping wastewater flows to the primary PH adjusting tank 201, is treated and then sequentially passes through the Fenton oxidation module 202, the secondary PH adjusting tank 203 and the second chemical precipitation tank 204 and is communicated to the concentration unit 3 in a manner of being combined with the effluent of the anode treatment unit 1. Fenton reaction is carried out by hydrogen peroxide and ferrous ion Fe under acidic condition ²⁺ Generates hydroxyl free radicals with strong oxidizing ability and initiates more other active oxygen to realize degradation of organic matters, and the oxidation process is chain reaction.

According to a preferred embodiment, the Fenton oxidation module 202 has a Fenton reaction tower for removing refractory long-chain organics for COD reduction and a coagulation reaction tank for flocculating metal ions and precipitating effluent. The process flow of the Fenton oxidation module 202 includes: the effluent of the primary PH adjusting tank 201 is sent to a Fenton reaction tower by a feed pump, the pollutants which are difficult to degrade in the wastewater are oxidized and degraded, the effluent of the Fenton reaction tower automatically flows to a neutralization tank, liquid caustic soda is added in the neutralization tank, and the wastewater is neutralized to neutrality; the wastewater in the neutralization pond automatically flows into a degassing pond, and a small amount of bubbles in the wastewater are removed through air blast stirring; the effluent from the degassing tank automatically flows into a coagulation reaction tank, and flocculant and PAM are added into the tank for full reaction, so that iron mud in the wastewater is flocculated; and (3) allowing the wastewater after the coagulation reaction to flow into a final sedimentation tank, precipitating iron mud therein, discharging supernatant reaching the standard, and placing the supernatant into a secondary PH adjusting tank 203. And the final sedimentation tank iron mud is pumped to a mud treatment system by a mud pump for treatment. Fenton oxidation reaction has the capability of removing COD which is difficult to degrade. The Fenton oxidation method is used as a pretreatment process before wastewater treatment, and the strong oxidation capacity of hydroxyl radicals is used for removing refractory long-chain organic matters, so that the influence of high COD on the membrane performance of a subsequent process system is avoided.

According to a preferred embodiment, the effluent of the anodic treatment unit 1 and the etching deplating treatment unit 2 is discharged to the third chemical precipitation tank 4 and sequentially passes through the high-density tank 5, the anaerobic-aerobic module 6 and the activated carbon unit 7 to enter the concentration unit 3, wherein the activated carbon unit 7 is filled with granular activated carbon for adsorbing free matters, microorganisms and heavy metal ions in the wastewater and high-salt resistant activated carbon for removing CODcr, chromaticity, colloid, heavy metals and SS. And the effluent of the third chemical sedimentation tank 4 enters a high-density tank 5, and a flocculating agent and a coagulant aid are added, so that metal ions, calcium and magnesium ions and the flocculating agent form alum flowers to be settled at the bottom of the inclined plate sedimentation tank, and the separation of the metal ions, the calcium and magnesium ions and the clean water is realized. The water outlet pump is led into the anaerobic and aerobic module 6, and 3000m can be additionally arranged ³ dMBR membrane plant. The denitrifying bacteria and heterotrophic bacteria in the anaerobic tank are utilized to remove nitrate and organic matters in the wastewater, and the nitrifying bacteria and aerobic bacteria in the aerobic tank are utilized to remove organic matters, so that ammonia nitrogen is converted into nitrate. Nitrate generated by the aerobic tank is further removed in the anaerobic tank through internal circulation between the anaerobic tank and the aerobic tank, and residual organic matters in the aerobic tank can also be used as a carbon source of denitrifying bacteria in the anaerobic tank, so that the cost of additional carbon sources is reduced. Elastic filler is added into the anaerobic tank and the aerobic tank, heterotrophic bacteria and autotrophic bacteria grow on the surface of the filler in an attached mode, and the micro-scale is improved Biomass and biological treatment load, and simultaneously can independently control sludge age and sludge concentration, and reduce the SS concentration of effluent. The effluent of the anaerobic and aerobic module 6 enters an activated carbon unit 7 to remove suspended matters, colloid, humus, COD, organic matters, iron colloid and the like in the wastewater, so that the operation safety of the back-stage reverse osmosis device is improved.

According to a preferred embodiment, the first materialized precipitation tank 102, the second materialized precipitation tank 204 and the third materialized precipitation tank 4 are generally composed of a reaction tank (fast mixing tank), a coagulation tank (slow mixing tank), a precipitation tank. Specifically, a rapid mixing pool: the sewage and the added medicament are fully and uniformly mixed by utilizing the rapid water flow, and chemical reaction is carried out, so that heavy metals are precipitated. Slow mixing pool: the alum flowers in the sewage are mutually and flexibly collided by utilizing the slow water flow, so that the alum flowers are collided and combined to form large-particle alum flowers, and the sedimentation performance of the large-particle alum flowers is better. And (3) a sedimentation tank: the alum flowers and the water are separated under the neutral action by utilizing the specific gravity difference of the alum flowers and the water, so that the purposes of removing heavy metals, pollutants and the like in the sewage are achieved.

According to a preferred embodiment, the anaerobic-aerobic module 6 comprises an anaerobic tank positioned at the front section and an aerobic tank positioned at the rear section, heterotrophic bacteria in the anaerobic tank remove nitrogen and phosphorus in the wastewater through denitrification, the aerobic tank ammonifies protein and fat, the ammonifies the wastewater after the ammonification through nitrification of autotrophic bacteria and returns the wastewater to the anaerobic tank through reflux control, so that the wastewater is further subjected to harmless treatment. The anaerobic tank is mainly used for denitrification and dephosphorization; the aerobic tank is mainly used for removing organic matters in water. The anaerobic-aerobic module 6 can remove organic pollutants in the wastewater and also can remove nitrogen and phosphorus at the same time. The anaerobic and aerobic module 6 connects the front anaerobic tank and the rear aerobic tank in series, the DO of the anaerobic tank is not more than 0.2mg/L, and the DO of the aerobic tank is=2-4 mg/L. The heterotrophic bacteria in the anaerobic tank hydrolyze suspended pollutants such as starch, fiber, carbohydrate and the like in the sewage into organic acid, so that macromolecular organic matters are decomposed into micromolecular organic matters, insoluble organic matters are converted into soluble organic matters, and when the products after anoxic hydrolysis enter an aerobic tank for aerobic treatment, the biodegradability and the oxygen efficiency of the sewage can be improved; at the position of In the aerobic tank, heterotrophic bacteria ammonify pollutants such as protein, fat and the like (N on an organic chain or amino in amino acid) to release ammonia (NH) ³ 、NH ⁴⁺ ) Under the condition of sufficient oxygen supply, the nitrifying action of autotrophic bacteria can make NH ³ -N(NH ⁴⁺ ) Oxidation to NO ^3- Returning to the anaerobic tank through reflux control, and under the anoxic condition, denitrifying the heterotrophic bacteria to remove NO ^3- Oxidized into molecular nitrogen (N2) to complete the ecological cycle of C, N, O and realize the harmless treatment of sewage.

Preferably, the high-density tank 5 is provided with multistage mixing and flocculation reactions, and can provide proper hydraulic conditions by adjusting mechanical stirring strength according to different speed gradients of mixing, flocculation reactions and precipitation, so that a good flocculation effect is achieved, and the alum forming effect is better than that of a conventional mechanical accelerating sedimentation tank. The high-density tank 5 flows back to the inlet of the flocculation reaction tank through sludge to provide a large amount of condensation nuclei for flocculation reaction, so that the collision effect of the flocculation reaction is enhanced, the generated alum blossom is very compact, and the alum blossom can be rapidly separated from clear water. The sludge reflux pump adopts a screw pump, the screw pump is a positive displacement pump, the outflow is a stable continuous flow, and the sludge alum can be minimally destroyed in the pumping process. The screw pump is selected to have a lower rotation speed so as to achieve the longest service life of the rubber stator. The shaft seal adopts a mechanical seal and has an out-of-band clean water flushing scheme, so that particles in the sludge can be effectively prevented from entering the shaft seal, and water leakage is avoided. The turbidity of the effluent of the conventional mechanical acceleration sedimentation tank is generally 5-10 NTU, and the effluent of the high-density clarification tank is generally about 1-5 NTU, so that the operation load of the subsequent high-strength membrane is greatly reduced. And an inclined tube clarification area is arranged above the solid-liquid separation area, so that trace fine alum flowers are further effectively removed, and the water outlet effect is improved. The flocculation reaction is enhanced by adding a small amount of Polymer (PAM), the addition amount of the general flocculation reaction is about 0.5mg/L, and the addition amount of the PAM is controlled to be less than 0.3mg/L under the condition that a membrane treatment process is arranged subsequently, so that the minimum PAM residual amount in the effluent is ensured, and adverse effects on a membrane treatment system are avoided.

Preferably, the activated carbon unit 7 can be a steel-concrete type filtering tank or a tank filtering device. Preferably a canister filter device. The shell is generally made of stainless steel or glass fiber reinforced plastic, and is internally filled with granular activated carbon for filtering free matters, microorganisms and partial heavy metal ions in water, and can effectively reduce the chromaticity of the water, improve the quality of the effluent water and prevent pollution, in particular to prevent pollution caused by free residual chlorine poisoning of a rear-stage reverse osmosis membrane, ion exchange resin and the like. The adsorption effect of the activated carbon is that organic matters and toxic substances in sewage or wastewater are removed by adsorption through the characteristic of porous appearance of the activated carbon solid, so that the purification purpose is achieved. The activated carbon has stronger adsorption capacity for organic matters with molecular weight within 500-1000 scale. Adsorption of organic matter by activated carbon is affected by its pore size distribution and polarity of the organic matter. The greater the solubility, the greater the hydrophilicity, the poorer the adsorptivity of activated carbon to it. On the contrary, the catalyst has strong adsorption capacity on organic matters with small solubility, poor hydrophilicity, weak polarity, such as benzene compounds, phenol compounds and the like. The use of activated carbon in high-salt wastewater treatment for COD reduction has different requirements from those of general sewage, and longer contact time is required in high-salt wastewater treatment. The contact time of the hollow bed in the sewage is generally 20-40 min, and the designed contact time of the hollow bed in the sewage is 60-120 min, so that larger equipment and more filling amount of the adsorption material are generally required.

The high-salt-resistant activated carbon used in the invention is an adsorption material with a large number of functional groups, and is characterized by the pore structure and the functional groups, so that the adsorption material has wide application space in the field of sewage treatment and mainly has the function of removing pollutants such as CODcr, chromaticity, colloid, heavy metal, SS and the like; the adsorption process is a process of trapping pollutants in a suspended state in water, and the trapped suspended matters are filled in pore channels, surfaces and gaps of the adsorption material. The capacity of the adsorbent material to retain suspended matter is determined by the specific surface area of the adsorbent material. At low flow rates, the filtering capacity of the adsorbent material is mainly due to the sieving action of the adsorbent material; at high flow rates, the filtering capacity of the adsorbent material results from the adsorption of the adsorbent material particle surfaces. In the filtering process, the larger the specific surface area of the adsorption material particles is, the stronger the adhesion to suspended matters in water is.

According to a preferred embodiment, the medium pressure concentration membrane module 301 obtains a first produced water and a first concentrated water, the first concentrated water is sent to the high pressure concentration membrane module 302 for desalination concentration to obtain a second produced water and a second concentrated water, wherein the first produced water and the second produced water are sent to the reverse osmosis membrane unit 8 and solutes and hydrosolvents in the produced water are separated in a two-stage separation manner so that the first produced water and the second produced water reach a reuse water standard, and the second concentrated water is sent to the crystallization unit 9. The pretreated qualified raw water enters a medium-pressure concentration membrane assembly 301 and a high-pressure concentration membrane assembly 302 which are arranged in a pressure container, water molecules and a very small amount of small molecular weight organic matters pass through a membrane layer, are concentrated through a collecting pipeline, and then are led to a water production pipe to be injected into a reverse osmosis water tank. Otherwise, the concentrated water is concentrated through the other group of collecting pipelines and then is led to a concentrated water discharge pipe to be discharged into a concentrated water tank. A series of control valves, monitoring meters and a program-controlled operating system are arranged on water inlet pipelines, water production pipelines and concentrated water pipelines of the system so as to ensure systematic operation of equipment with long quality and quantity guarantee. It comprises the following unit devices: a 5 μm cartridge filter; a dosing device; a high pressure pump; medium/high voltage body means; a cleaning and flushing system; the system is provided with a standby device for medium-pressure reverse osmosis and high-pressure reverse osmosis, so that online cleaning is guaranteed. The reverse osmosis equipment adopts the most advanced, energy-saving and effective membrane separation technology of the current generation, and the principle of the reverse osmosis equipment is as follows: under the action of the osmotic pressure higher than the solution, the solute can not permeate and the water solvent can permeate the semipermeable membrane, so that the solute and the water solvent are separated. During long-term operation of ultrafiltration membranes, reverse osmosis membranes and the like, a considerable amount of inorganic particles, scales, microorganisms and other pollution blocking components can be gradually accumulated on the surfaces of the membrane elements, and the pollutants cause the reduction of system performance (desalination rate and water yield) and the increase of pressure difference between an inlet and an outlet of the component; periodic cleaning of membranes is one of the primary measures to prevent membrane fouling. The system is provided with a cleaning device which comprises a cleaning water pump, a cleaning water tank and a precision filter for cleaning. The pore diameter of the reverse osmosis membrane is very small, so that the reverse osmosis equipment can effectively remove dissolved salts, colloid, microorganisms, organic matters and the like in water; the reverse osmosis equipment can produce pure water and high-purity water to meet users of different industries and different demands, and meanwhile, the degree of automation is high.

According to a preferred embodiment, the reverse osmosis membrane unit 8 includes a primary osmosis membrane module 801, a secondary osmosis membrane module 802, and an ultrapure water module. The first-stage osmosis membrane module 801 is used for treating high-pressure reverse osmosis produced water, and a reverse osmosis system utilizes the characteristics of a reverse osmosis membrane to remove most of soluble salt and chloride ions in the water. The produced water of the first-stage osmosis membrane module 801 enters the second-stage osmosis membrane module 802, and the concentrated water of the first-stage osmosis membrane module 801 flows back into the high-pressure concentration membrane module 302. In order to ensure the final effluent quality and the safer and more stable operation of the system, the membrane inlet system with high TDS and COD can cause certain damage, reduce the desalination rate, and better ensure the stable water quality, the secondary osmosis membrane module 802 is arranged, and the device comprises a cartridge filter, a high-pressure pump, a secondary osmosis membrane module body and a dosing device. The ultrapure water module combines electrodialysis technology and ion exchange technology, and realizes directional migration of ions under the action of a direct current electric field through the selective permeation action of anion and cation exchange membranes on anions and cations and the ion exchange action of ion exchange resin, so that deep desalting of water is completed, and the water quality can reach more than 15MΩ & cm. The ion exchange resin is regenerated by hydrogen ions and hydroxide ions generated by water electrolysis while desalting, so that ultrapure water can be continuously prepared without acid-base chemical regeneration. It has the characteristics of advanced technology, simple and convenient operation and excellent environmental protection

According to a preferred embodiment, the crystallization unit 9 performs three-effect forced circulation mixed flow evaporation crystallization and rotary drum on the second concentrated water, and the second concentrated water is evaporated into mixed salt to be used as solid waste treatment, wherein condensed water generated in the evaporation process of the crystallization unit 9 enters a condensed water pipeline to be cooled and then is discharged into the anaerobic-aerobic module 6. The specific flow comprises the following steps:

the material flow direction is as follows: raw materials are respectively preheated by a feed pump to a raw steam condensate water preheater, then sequentially enter a first-effect evaporator, a second-effect evaporator and a third-effect evaporator, are conveyed to a flash evaporation crystallizer by a second-effect discharge pump after being evaporated and concentrated to a certain concentration, and then enter a centrifugal machine for centrifugal separation: and returning the centrifuged mother liquor to an evaporator, centrifuging the solid to obtain mixed salt, and sending the enriched residual mother liquor to a drying system for further treatment.

Steam and condensate flow direction: the saturated raw steam enters the shell side of the first-effect heating chamber to exchange heat with the raw material, and enters a condensate water preheater to preheat the raw material after condensation, so that the condensate water waste heat can be recycled, and the condensate water waste heat returns to the boiler room after preheating; the secondary steam generated by the first-effect separation chamber is used as a heat source of the second-effect heating chamber and exchanges heat with the tube side feed liquid to be condensed; the secondary steam generated by the secondary separation chamber is used as a heat source of the three-effect heating chamber, exchanges heat with the tube side solution, condenses and enters a condensation water tank to be collected; the secondary steam generated by the triple-effect separation chamber exchanges heat with the circulating water of the indirect condenser shell side to be condensed, the condensed water enters a condensed water tank to be collected, and then is pumped to a secondary steam condensed water preheater to preheat raw materials, and the preheated raw materials are sent to the outside for reprocessing, and noncondensable gas in the indirect condenser is discharged by a vacuum pump.

Example 2

This embodiment may be a further improvement and/or addition to embodiment 1, and the repeated description is omitted. In addition to this embodiment, the preferred implementation of the other embodiment may be provided in whole and/or in part without conflict or contradiction.

Heavy metal wastewater in the electronic industry can be mainly divided into two streams, namely anode wastewater and etching deplating wastewater. The metal ion concentration and the organic matter content of the anode wastewater are lower than those of the etching deplating wastewater, so that the heavy metal wastewater in the electronic industry can be divided into wastewater with high metal ion concentration and high organic matter content and wastewater with low metal ion concentration and low organic matter content. In order to reduce the treatment load of the front-end equipment of the heavy metal wastewater in the electronic industry and save capital investment and later operation cost, partial COD and metal ions of the wastewater with high metal ion concentration and high organic matter content are removed.

According to a preferred embodiment, before the heavy metal wastewater of the electronics industry enters the anode treatment unit 1 and/or the etching-stripping treatment unit 2, the quality of the wastewater is identified for selective discharge into the anode treatment unit 1 and/or the etching-stripping treatment unit 2. Wherein, the waste water with high metal ion concentration and high organic matter content is discharged into the etching deplating treatment unit 2, and the waste water with low metal ion concentration and low organic matter content is discharged into the anode treatment unit 1. Or, when the water quality of the wastewater fluctuates (i.e., the wastewater when the metal ion concentration and the organic matter content greatly fluctuate within a set time), the wastewater is discharged into the etching deplating treatment unit 2. The inlet pipe of the heavy metal wastewater in the electronic industry before entering the anode treatment unit 1 and/or the etching deplating treatment unit 2 is provided with a valve assembly (for example, a solenoid valve). When the monitoring unit detects that the quality of the incoming water fluctuates, the valve switches the waste water to the etching deplating treatment unit 2, so that the normal running anode treatment unit 1 is prevented from being impacted.

According to a preferred embodiment, when the heavy metal wastewater in the electronic industry enters the etching deplating treatment unit 2, the Fenton oxidation module 202 is pumped to treat the heavy metal wastewater, mainly treat organic matters and partial heavy metal ions, and the adjusted wastewater is subjected to materialized precipitation and then is discharged from the anode treatment unit 1 to be combined, so that the load of a front-stage wastewater treatment facility is reduced, and the capital investment and the later-stage operation cost are saved.

Example 3

The invention also relates to a zero emission treatment method which can be implemented by the system of the invention and/or other alternative components. The method of the present invention is implemented, for example, by using various components in the system of the present invention.

The method comprises the following steps:

s1: the anode treatment unit 1 carries out pH value adjustment and physical and chemical precipitation on the anode wastewater to be treated;

s2: removing COD and metal ions in the etching plating removal wastewater to be treated based on degradation organic matters in the etching plating removal treatment unit 2, and performing two-stage adjustment of pH value and physical and chemical precipitation;

s3: the treated anode wastewater and the etched plating-removal wastewater are desalted and concentrated in a concentrating unit 3 to obtain produced water and concentrated water, wherein the concentrating unit 3 comprises a medium-pressure concentrating membrane assembly 301 and a high-pressure concentrating membrane assembly 302, the treated anode wastewater and the etched plating-removal wastewater are sent to the medium-pressure concentrating membrane assembly 301 to obtain first produced water and first concentrated water, and the high-pressure concentrating membrane assembly 302 performs desalination and concentration on the first concentrated water obtained by the medium-pressure concentrating membrane assembly 301 based on reverse osmosis membrane characteristics to obtain second produced water and second concentrated water.

Preferably, in step S1: the anode treatment unit 1 is communicated with the concentration unit 3 in a manner of adjusting the pH value of the anode wastewater to be treated and performing physical and chemical precipitation, so that the effluent of the anode treatment unit 1 can be communicated to the concentration unit 3 in a manner of combining with the effluent of the etching deplating treatment unit 2 within a set pH value range.

Preferably, steps S1 and S2 comprise at least the following sub-steps:

s11: identifying the water quality of the wastewater to be treated, and if the wastewater is the wastewater with high metal ion concentration and high organic matter content, storing the wastewater into a primary PH adjusting tank 201, and executing step S21; if the wastewater is low in metal ion concentration and low in organic matter content, the wastewater is stored in the pH adjusting tank 101, and step S12 is performed.

S12: and (3) regulating the pH value of the wastewater to be treated and carrying out physical and chemical precipitation.

S21: the wastewater to be treated is pumped into the Fenton oxidation module 202 for treatment, mainly organic matters and partial heavy metal ions are treated, and the adjusted wastewater is subjected to physical and chemical precipitation and then is combined with the water discharged from the anode treatment unit 1, so that the load of a front-stage wastewater treatment facility is reduced, and the capital investment and the later-stage operation cost are saved.

S22: the combined effluent is pumped into a third chemical precipitation tank 4 and allowed to dwell for a pre-designed wastewater residence time.

S23: when the residence time of the wastewater in the third biochemical sedimentation tank 4 reaches a preset value, the wastewater sequentially passes through the high-density tank 5, the anaerobic-aerobic module 6 and the activated carbon unit 7 to obtain qualified raw water, and the qualified raw water is pumped into the concentration unit 3.

Preferably, step S3 comprises at least the following sub-steps:

s31: raw water enters a medium-pressure concentration membrane module 301 to obtain first produced water and first concentrated water, and the first concentrated water is sent to a high-pressure concentration membrane module 302 to be desalted and concentrated to obtain second produced water and second concentrated water.

S32: the first produced water and the second produced water are sent to the reverse osmosis membrane unit 8 and solutes and hydrosolvents in the incoming water are separated in a two-stage separation manner so that the first produced water and the second produced water reach the reuse water standard, and the second concentrated water is sent to the crystallization unit 9.

S33: the reverse osmosis membrane unit 8 comprises a first-stage osmosis membrane module 801 and a second-stage osmosis membrane module 802, wherein the first-stage osmosis membrane module 801 is used for treating high-pressure reverse osmosis produced water, the produced water of the first-stage osmosis membrane module 801 enters the second-stage osmosis membrane module 802, and concentrated water of the first-stage osmosis membrane module 801 flows back into the high-pressure concentration membrane module 302 so as to further remove soluble salt and chloride ions in the water.

S34: in the crystallization unit 9, the second concentrated water is subjected to three-effect forced circulation mixed flow evaporation crystallization and a rotary drum, and is evaporated into mixed salt to be used as solid waste treatment, wherein condensed water generated in the evaporation process of the crystallization unit 9 enters a condensed water pipeline to be cooled and then is discharged into the anaerobic and aerobic module 6.

The final produced water quality of the step S33 meets the requirement of reuse water.

Example 4

This embodiment is a further complement to the embodiments described above.

The embodiment provides a processing method.

The heavy metal wastewater in the electronic industry mainly comprises anode wastewater and etching deplating wastewater. The main components of the anode wastewater are copper and nickel, and nitrate radical, phosphorus, ammonia nitrogen and organic matters are carried; the etching deplating waste water has complex components and contains various metal ions (copper, nickel, chromium, manganese, aluminum and iron) and a large amount of organic matters and inorganic matters (nitrate radical and phosphorus). The PH of the water inlet of the two water streams is 2-3, and the water belongs to the water quality with meta-acid property. However, the wastewater delivery treatment cost is high, the impact on the water treatment process and equipment is too large, the fluctuation of the drainage index of the sewage treatment plant is often caused, the plating removal jig and defective products are removed, and the water quality is greatly influenced by the product yield. Therefore, finding a proper heavy metal wastewater treatment process, which can stably, efficiently and inexpensively treat the wastewater, is a primary problem at the present stage.

Aiming at the treatment condition requirements of two waste water, namely anode waste water and etching deplating waste water, the inventor of the invention provides a technological process method with targeted adjustment to ensure the reliability and stability of the technological process, and in the method, the specific key method or technical key points are as follows:

(1) The concentration of metal ions and the content of organic matters in the anode wastewater are lower than those in the etching-stripping wastewater, so that partial COD and metal ions in the etching-stripping wastewater are removed, the load of a front-stage wastewater treatment facility can be reduced, and the capital investment and the later-stage operation cost are saved.

(2) According to the characteristics of low PH value, high metal ion concentration and high COD of the etching deplating wastewater, the wastewater is considered to be firstly introduced into a Fenton oxidation device, the hydroxyl free radical generated by ferrous iron and hydrogen peroxide is utilized to attack a long-chain structure of the difficultly-degradable COD, and meanwhile, the metal ion is also subjected to the removal effect of flocculation precipitation, so that the capability of removing organic matters and part of heavy metal ions is achieved, and meanwhile, the acid amount used for adjusting the PH value can be saved. Because the concentration of heavy metal ions in the etching deplating wastewater is high, a two-stage materialized sedimentation tank in the original wastewater treatment process is designed and utilized to remove the heavy metal ions in the wastewater, the hardness of the wastewater is reduced, the damage of calcium and magnesium ions to a sewage recycling membrane device is reduced, and the engineering investment cost is saved.

(3) The heavy metal ions in the anode wastewater mainly comprise nickel, and the concentration of the metal ions is far lower than that of the etching deplating wastewater. After passing through the materialized sedimentation tank, the materialized sedimentation tank effluent of the anode wastewater and the two-stage materialized effluent of the etched deplating wastewater are combined and enter the materialized sedimentation tank, the materialized effluent enters a high-density tank, and a flocculating agent and a coagulant aid are added to enable metal ions, calcium magnesium ions and the flocculating agent to form alum flowers to be settled at the bottom of the inclined plate sedimentation tank, so that the separation of the metal ions, the calcium magnesium ions and the clean water is realized. Effluent is pumped into the anaerobic-aerobic module 6 and 3000m by using the existing system ³ dMBR membrane plant. The denitrifying bacteria and heterotrophic bacteria in the anaerobic tank are utilized to remove nitrate and organic matters in the wastewater, and the nitrifying bacteria and aerobic bacteria in the aerobic tank are utilized to remove organic matters, so that ammonia nitrogen is converted into nitrate. Nitrate generated by the aerobic tank is further removed in the anaerobic tank through internal circulation between the anaerobic tank and the aerobic tank, and residual organic matters in the aerobic tank can also be used as a carbon source of denitrifying bacteria in the anaerobic tank, so that the cost of additional carbon sources is reduced. Elastic filler is added into the anaerobic-aerobic module 6, heterotrophic bacteria and autotrophic bacteria grow on the surface of the filler in an attached mode, the microbial biomass and the biological treatment load are improved, and meanwhile, the device can be independently controlledSludge age and sludge concentration, and reduce the SS concentration of the effluent.

(4) The wastewater enters an activated carbon unit 7, suspended matters, colloid, humus, COD, organic matters, iron colloid and the like in the wastewater are removed further, the operation safety of a rear-stage reverse osmosis device is improved, then the wastewater is subjected to reduction treatment by using a medium-pressure concentration membrane assembly 301 and a high-pressure concentration membrane assembly 302, and produced water enters a primary osmosis membrane module 801, a secondary osmosis membrane module 802 and an ultrapure water module, and is further desalted, so that the quality of the produced water meets the requirement of reuse water. Concentrated water enters a crystallization device and a rotary drum of the triple-effect evaporator, is evaporated into mixed salt and is used as solid waste to be entrusted with qualification unit treatment, condensed water generated in the evaporation process enters a condensate pipe for cooling and is discharged into an anaerobic-aerobic module 6 for treatment.

Example 5

This embodiment is a further complement to the embodiments described above.

The invention provides a Fenton oxidation module 202, wherein the Fenton oxidation module 202 is provided with a Fenton reaction tower for removing refractory long-chain organic matters and reducing COD. The Fenton oxidation method is used as a pretreatment process before wastewater treatment, and the strong oxidation capacity of hydroxyl radicals is used for removing refractory long-chain organic matters, so that the influence of high COD on the membrane performance of a subsequent process system is avoided. However, in the prior art, a reaction tower design for treating wastewater is generally adopted, and a mode of adding hydrogen peroxide and ferrous ions is adopted to generate hydroxyl radicals so as to oxidize and degrade organic matters. However, because the reaction degree of the hydrogen peroxide and the ferrous ions cannot be judged, the addition amount of the ionic metal ions and the hydrogen peroxide is difficult to judge and control, so that the active substances can cause secondary pollution to the wastewater, the ferrous ions after the reaction are oxidized into ferric ions to generate coagulating sedimentation, and a large amount of iron mud is formed by the iron ions to block the wastewater inlet, so that the maintenance cost of the reaction tower is increased, and the service life is reduced.

For the above reasons, the present invention proposes a Fenton reaction tower that prevents the generation of a large amount of iron mud by controlling the concentrations of hydrogen peroxide and ferrous ions added and separating a reaction part from a wastewater inlet.

According to a preferred embodiment, the reaction column 1O comprises a barrier layer 1001, an inlet layer 1002 and an outlet layer 1003. Wherein wastewater enters the water inlet layer 1002 from the primary PH adjusting tank 201 and is lifted up through the barrier layer 1001 by the first pump 1004 into the water outlet layer 1003. The reaction tower 10 further includes a cathode portion 1005, an anode portion 1006, an aeration portion 1007, and an electric field introducing device 1008. In the treatment process of heavy metal wastewater, the wastewater enters the water inlet layer 1002 through a pipeline, and is conveyed to the water outlet layer 1003 through the barrier layer 1001 under the lifting action of the first pump 1004. Through setting up the reaction position that adds medicine in the upper strata to isolated through the barrier layer 1001, make into water layer 1002 only be used for waste water buffering, thereby let the iron mud that adds medicine reaction in-process probably produce can not block up waste water inlet, and through the power of control first pump 1004, can adjust the treatment effeciency of waste water, increased the shock resistance of system. Preferably, the barrier layer 1001 is located between the water entry layer 1002 and the water exit layer 1003. The barrier 1001 is located one third from bottom to top to give consideration to the sufficient depth of both the dosing reaction space and the wastewater entry space. The barrier layer 1001 is also provided for the purpose of: due to the continuous operation of the first pump 1004, the water inlet layer 1002 gradually forms a negative pressure environment, so that the inflow speed of the wastewater is increased, and the wastewater treatment efficiency of the whole system is increased. The electric field introducing device 1008 performs in-situ electrolysis on the wastewater pumped into the water outlet layer 1003. The water outlet layer 1003 may be provided with a sensor to detect hydrogen peroxide and ferrous ion content in the wastewater in real time, thereby indirectly controlling hydrogen peroxide and ferrous ion generation rate by controlling the magnitude of current of the electric field introduction device 1008 and the aeration amount of the aeration portion 1007. Preferably, controlling the magnitude of the current can indirectly control the rate of production of divalent metal ions, and thus the hydroxide concentration in the reaction column 10. The generation rate of divalent metal ions is controlled, so that quenching reaction with hydroxyl is effectively avoided, and the utilization rate of hydrogen peroxide is improved. Preferably, the control of aeration can indirectly control the amount of volatile organic compounds and/or semi-volatile organic contaminants in the wastewater, the dissolved oxygen content in the wastewater, and the stimulation of oxidative decomposition of organic contaminants by microorganisms in the wastewater. The reaction tower 10 of the invention adjusts the hydrogen peroxide and ferrous ion production rate by changing the current and aeration, and effectively avoids the cost waste caused by excessive hydrogen peroxide.

According to a preferred embodiment, an electric field is applied to the water layer 1003 by means of the electric field introduction means 1008 to electrolyze the wastewater to obtain radical precursor hydrogen peroxide at the cathode portion 1005 and to generate active radical hydroxide under contact of metal ions at the anode portion 1006, thereby achieving oxidative degradation of the wastewater. The mode of adopting an external electric field ensures that no additional hydrogen peroxide is needed to be added for reaction, thereby reducing the cost consumption of the external oxidant. Preferably, the anode portion 1006 is formed of metal and the cathode portion 1005 is formed of a carbon rod. The present invention can oxidize high-valence metal ions to low-valence metal ions in the cathode 1005, thereby realizing the secondary utilization of the metal ions. The recycling ensures that the catalysis utilization rate of ferrous ions is increased, the catalysis efficiency of hydrogen peroxide is increased, the coagulating sedimentation generated by ferric ions is reduced, and the wastewater treatment cost is reduced. The reaction column 10 of the present invention operates on the principle that (iron ions are taken as an example): the iron ions are oxidized to divalent free iron ions in the anode portion 1006, and the divalent iron ions undergo Fenton reaction with hydrogen peroxide generated in the cathode portion 1005 to generate hydroxide and ferric ions. The ferric ions receive electrons at the cathode portion 1005 and are converted to ferrous ions for entry into the Fenton reaction of the next cycle. The generation rate of hydrogen peroxide and ferrous ions is indirectly controlled through the current and the aeration quantity, so that the ferrous ions and hydroxyl ions are prevented from reacting, and a large amount of iron mud is prevented from being formed. It should be understood that the above iron ions are only one metal ion proposed for illustrating the operation principle of the reaction tower 10, and do not represent the problem that other metal ions capable of performing Fenton-like reaction cannot be used, so as to use suitable metal materials in different environments. For example, a metal material having various valence states such as magnesium, copper, or silver can be used. The cathode portion 1005 can be made of a material including a carbon rod or a conductive ceramic.

According to a preferred embodiment, the barrier 1001 is further provided with a second pump 1009 for feeding the precipitated iron sludge to the conditioning chamber 1010. The conditioning chamber 101O is simultaneously connected to the water outlet layer 1003. Since the PH of the effluent 1003 is required to be maintained, the PH cannot be adjusted to be alkaline, and the cathode 1005 converts metal ions, but the generation of iron sludge cannot be completely prevented. In this regard, the adjustment chamber 1010 is configured to receive the iron mud that may be generated, by adjusting the PH in the adjustment chamber 1010 to be alkaline, the iron mud flows back to the water outlet layer 1003 after entering the adjustment chamber, so that the iron mud is recycled, the catalytic capability and the catalytic efficiency thereof are improved, the utilization rate is increased, and the yield of the iron mud in the Fenton oxidation module 202 is reduced. Preferably, the reaction tower 10 is further provided with an air pump for pumping out carbon dioxide, which is a final product of the organic matter after the oxidative degradation of hydroxyl groups. The extracted carbon dioxide can act as a regulator to the regulator chamber. That is, the extracted carbon dioxide is introduced into the conditioning chamber 1010, so that the carbon dioxide content is increased and carbonate is generated, the pH is adjusted back to alkaline, the consumption of pH value adjustment is reduced, and the wastewater treatment cost is reduced.

Throughout this document, the word "preferably" is used in a generic sense to mean only one alternative, and not to be construed as necessarily required, so that the applicant reserves the right to forego or delete the relevant preferred feature at any time.

It should be noted that the above-described embodiments are exemplary, and that a person skilled in the art, in light of the present disclosure, may devise various solutions that fall within the scope of the present disclosure and fall within the scope of the present disclosure. It should be understood by those skilled in the art that the present description and drawings are illustrative and not limiting to the claims. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A zero emission treatment system is characterized by comprising an anode treatment unit (1), an etching deplating treatment unit (2) and a concentration unit (3),

the anode treatment unit (1) is communicated with the concentration unit (3) in a manner of adjusting the pH value of anode wastewater to be treated and performing physical and chemical precipitation;

the etching deplating treatment unit (2) removes COD and metal ions in the etching deplating wastewater to be treated based on degradation organic matters, and carries out two-stage adjustment of pH value and physical and chemical precipitation;

The concentration unit (3) carries out desalination concentration on the treated anode wastewater and the etched plating-removal wastewater to obtain produced water and concentrated water, wherein,

the concentration unit (3) comprises a medium-pressure concentration membrane assembly (301) and a high-pressure concentration membrane assembly (302), the treated anode wastewater and the treated etching-stripping wastewater are sent into the medium-pressure concentration membrane assembly (301) to obtain first produced water and first concentrated water, and the high-pressure concentration membrane assembly (302) is used for carrying out desalination concentration on the first concentrated water obtained by the medium-pressure concentration membrane assembly (301) based on reverse osmosis membrane characteristics to obtain second produced water and second concentrated water;

the anode treatment unit (1) comprises a pH adjustment tank (101), a first materialized sedimentation tank (102) and a pH callback tank (103), wherein the pH adjustment tank (101) and the pH callback tank (103) are respectively connected to the front end and the rear end of the first materialized sedimentation tank (102), so that the effluent of the anode treatment unit (1) can be communicated to the concentration unit (3) in a mode of combining with the effluent of the etching deplating treatment unit (2) within a set pH value range;

the etching deplating treatment unit (2) comprises a primary pH regulating tank (201), a Fenton oxidation module (202), a secondary pH regulating tank (203) and a second chemical sedimentation tank (204), wherein the primary pH regulating tank (201) runs separately and is communicated with each other in sequence, etching deplating wastewater flows to the primary pH regulating tank (201) firstly, then sequentially passes through the Fenton oxidation module (202), the secondary pH regulating tank (203) and the second chemical sedimentation tank (204) after being treated, and is communicated to the concentration unit (3) in a mode of combining with water outlet of the anode treatment unit (1).

2. The zero emission treatment system of claim 1, wherein the Fenton oxidation module (202) has a Fenton reaction tower for removing refractory long-chain organics for COD reduction and a coagulation reaction tank for flocculating metal ions and precipitating emissions.

3. The zero-emission treatment system according to claim 2, wherein the effluent of the anodic treatment unit (1) and the etching deplating treatment unit (2) is discharged to a third chemical precipitation tank (4) and sequentially passes through a high-density tank (5), an anaerobic-aerobic module (6) and an activated carbon unit (7) to enter the concentration unit (3), wherein,

the activated carbon unit (7) is filled with granular activated carbon for adsorbing free matters, microorganisms and heavy metal ions in wastewater and high-salt-resistant activated carbon for removing CODcr, chromaticity, colloid, heavy metal and SS.

4. A zero emission treatment system according to claim 3, wherein the anaerobic-aerobic module (6) comprises an anaerobic tank located at a front stage and an aerobic tank located at a rear stage, heterotrophic bacteria in the anaerobic tank remove nitrogen and phosphorus in the wastewater through denitrification, the aerobic tank ammonifies proteins and fats, the ammonifies the wastewater after ammonification through nitrification of the autotrophic bacteria and returns the wastewater to the anaerobic tank through reflux control, so as to further perform harmless treatment on the wastewater.

5. The zero release treatment system of claim 4, wherein the medium pressure concentrating membrane module (301) produces a first produced water and a first concentrate, the first concentrate is sent to the high pressure concentrating membrane module (302) for desalination concentration to produce a second produced water and a second concentrate, wherein,

the first produced water and the second produced water are sent to a reverse osmosis membrane unit (8) and solute and hydrosolvent in the incoming water are separated in a two-stage separation mode so that the first produced water and the second produced water reach a reuse water standard, and the second concentrated water is sent to a crystallization unit (9).

6. The zero-emission treatment system according to claim 5, wherein the crystallization unit (9) performs three-effect forced circulation mixed flow evaporation crystallization and drum on the second concentrated water, and the second concentrated water is evaporated into mixed salt to be used as solid waste treatment, wherein condensed water generated in the evaporation process of the crystallization unit (9) enters a condensed water pipeline to be cooled and then is discharged into the anaerobic aerobic module (6).

7. A zero emission treatment method, the method comprising:

the anode treatment unit (1) carries out pH value adjustment and physical and chemical precipitation on the anode wastewater to be treated;

Removing COD and metal ions in the etching plating removal wastewater to be treated based on degradation organic matters in an etching plating removal treatment unit (2), and performing two-stage adjustment of pH value and physical and chemical precipitation;

desalting and concentrating the treated anode wastewater and the etched deplating wastewater in a concentrating unit (3) to obtain produced water and concentrated water, wherein,

8. The zero-emission treatment method according to claim 7, wherein the anode treatment unit (1) comprises a pH adjustment tank (101), a first materialized sedimentation tank (102) and a pH callback tank (103), and the pH adjustment tank (101) and the pH callback tank (103) are respectively connected to the front end and the rear end of the first materialized sedimentation tank (102), so that the effluent of the anode treatment unit (1) can be communicated to the concentration unit (3) in a manner of combining with the effluent of the etching deplating treatment unit (2) within a set pH range.