CN111453920B

CN111453920B - A method and system for treating anodizing wastewater

Info

Publication number: CN111453920B
Application number: CN202010283421.5A
Authority: CN
Inventors: 罗小龙; 梁康祜; 赖日坤; 林国宁
Original assignee: Guangdong Shuiqing Environmental Protection Technology Co ltd
Current assignee: Guangdong Shuiqing Environmental Protection Technology Co ltd
Priority date: 2020-04-13
Filing date: 2020-04-13
Publication date: 2024-12-27
Anticipated expiration: 2040-04-13
Also published as: CN111453920A

Abstract

A method and system for treating anodizing wastewater, wherein the anodizing wastewater includes nickel-containing wastewater, inorganic wastewater, dyeing wastewater, and phosphorus-containing wastewater. The present invention provides methods for treating the above-mentioned nickel-containing wastewater, inorganic wastewater, dyeing wastewater, and phosphorus-containing wastewater, as well as nickel-containing wastewater treatment systems, inorganic wastewater treatment systems, dyeing wastewater treatment systems, drainage systems, and phosphorus-containing wastewater treatment systems that implement the above-mentioned methods and are interrelated. After being treated by the method and system of the present invention, the anodizing wastewater on the production line can be fully circulated and purified, and the purified produced water can meet the discharge standards or be reused. The present invention solves the difficulties in the traditional anodizing wastewater treatment process and saves treatment costs.

Description

Anodic oxidation wastewater treatment method and system

Technical Field

The invention relates to the field of sewage purification, in particular to an anodic oxidation wastewater treatment method and system. Background

Anodic oxidation refers to electrochemical oxidation of a metal or alloy. Under the action of the corresponding electrolyte and specific process conditions, the metal and the alloy thereof form an oxide film on a metal product (anode) under the action of an external current, and the anode oxidation technology is used as a common and main technology in the surface treatment of the electroplating industry, and is widely applied in the electroplating industry, and a large amount of anode oxidation wastewater is generated, wherein the anode oxidation wastewater comprises nickel-containing wastewater, inorganic wastewater, dyeing wastewater, phosphorus-containing wastewater and the like.

Nickel-containing wastewater contains a class of pollutants which are strictly controlled by China, dyeing wastewater contains higher concentration chromaticity, and phosphorus-containing wastewater contains higher concentration phosphorus and greasy dirt, which are main treatment difficulties of anodic oxidation wastewater. With the increasingly strict discharge standards, the treatment difficulty of the anodic oxidation wastewater is increased, and the current method and system for treating the anodic oxidation wastewater are difficult to comprehensively treat various different types of wastewater in the anodic oxidation wastewater, and meanwhile, the treatment cost is higher. At present, the phosphorus-containing wastewater is generally dephosphorized by adopting a chemical precipitation method, and the common dephosphorizing agent for the phosphorus-containing wastewater comprises ferric salt, calcium salt and aluminum salt, and the follow-up membrane treatment is influenced due to the fact that the calcium salt is easy to scale. Therefore, the invention discloses an anodic oxidation wastewater treatment method and system which can save cost and reduce the addition of flocculating agent.

Disclosure of Invention

The invention aims to provide an anodic oxidation wastewater treatment method and system, which solve the treatment difficulty of the traditional anodic oxidation wastewater treatment process and save the treatment cost.

The technical scheme adopted for solving the technical problems is as follows:

A method for treating anodic oxidation wastewater, the anodic oxidation wastewater comprises nickel-containing wastewater, inorganic wastewater, dyeing wastewater and phosphorus-containing wastewater, and comprises the following steps:

The method for treating nickel-containing wastewater comprises the following steps:

Step 1a, nickel-containing wastewater is discharged into a nickel-containing wastewater regulating tank to regulate the water quality and the water quantity, and pumped into a first pH regulating tank, naOH is added, aeration and stirring are carried out, the pH value is regulated to 9-11, and nickel ions and hydroxide ions in the wastewater form nickel hydroxide precipitate to be separated out;

Step 1b, discharging the wastewater into a first quick mixing tank, adding a coagulant polyaluminium chloride PAC, performing aeration stirring, and coagulating the separated precipitate into larger particles;

Step 1c, then discharging the wastewater into a first slow mixing tank, adding a polymeric flocculant PAM, stirring, and forming large-scale flocs by particles in the water;

step 1d, discharging the sewage in the first slow mixing tank into a first primary sedimentation tank for gravity sedimentation, and periodically discharging the sedimented sludge into a sludge bucket and a nickel-containing sludge concentration tank;

step 1e, discharging the supernatant of the first primary sedimentation tank into a first pH adjusting tank, adding NaOH again, aerating and stirring, adjusting the pH value to 9-11, and separating nickel ions and hydroxide ions in the wastewater to form nickel hydroxide precipitate;

step 1f, discharging the wastewater into a first secondary rapid mixing tank, adding a coagulant polyaluminium chloride PAC, and performing aeration stirring to coagulate the separated precipitate into larger particles;

Step 1g, discharging the wastewater of the first secondary rapid mixing tank into the first secondary slow mixing tank, adding a polymeric flocculant PAM, stirring, and forming massive flocs by particles in the water under the action of adsorption net capturing;

Step 1h, discharging the wastewater of the first secondary mixing tank into a first inclined tube sedimentation tank for gravity sedimentation, enabling the sedimentated sludge to enter a sludge bucket, periodically discharging the sludge into a nickel-containing sludge concentration tank, carrying out filter pressing on the sludge in the nickel-containing sludge concentration tank through a first box filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a nickel-containing wastewater regulating tank for retreatment;

step 1i, discharging supernatant fluid of a first one-to-one inclined tube sedimentation tank into an intermediate clean water tank, adding sulfuric acid into the intermediate clean water tank to adjust the pH value to 6.5-7.5, aerating and stirring, pumping wastewater into a first one-to-one quartz sand filter for treatment, and directly discharging effluent water of the first one-to-one quartz sand filter into an inorganic clean water tank in an inorganic wastewater treatment system if the content of nickel ions is detected to be low;

step 2, an inorganic wastewater treatment method comprises the following steps:

Step 2a, inorganic wastewater is singly collected and discharged into an inorganic wastewater regulating tank to regulate the water quality and the water quantity, then the wastewater is pumped into a second pH regulating tank, naOH is added for aeration and stirring, the pH value is regulated to 8.5-9, and aluminum ions and hydroxide ions in the wastewater form aluminum hydroxide precipitate to be separated out;

step 2b, discharging the wastewater into a second rapid mixing tank, adding a coagulant polyaluminium chloride PAC, and performing aeration stirring to coagulate the separated precipitate into larger particles;

Step 2c, then discharging the wastewater into a second slow mixing tank, adding a polymeric flocculant PAM, stirring, and forming large-block flocs by particles in the water;

Step 2d, discharging the sewage in the second slow mixing tank into a second primary sedimentation tank for gravity sedimentation, discharging the precipitated sludge into a sludge bucket periodically, discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the comprehensive sludge concentration tank by a second box filter press, carrying out outward transport on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank for treatment;

step 2e, discharging supernatant fluid of the second primary sedimentation tank into an inorganic clean water tank, pumping wastewater of the inorganic clean water tank into a second quartz sand filter of a reuse water system for treatment, then treating the wastewater through an activated carbon filter, discharging filtered wastewater into a UF membrane system for treatment through a pipeline, adding sulfuric acid into a water inlet pipeline of the UF membrane system for regulating the pH value, adding reducing agent sodium bisulfate into the water inlet pipeline of the UF membrane system for regulating the oxidation-reduction potential, and adding a scale inhibitor into the water through a third pipeline mixer to enable the pH value of the water body to reach 6.5-7.5 before the treatment of the UF membrane system, so that the oxidation-reduction potential is controlled to be +/-150 mv;

Step 2f, discharging the water discharged from the UF water producing tank into a first-stage RO system, discharging the water produced by the first-stage RO system into a first-stage RO water producing tank, and discharging the concentrated water produced by the first-stage RO system into a dyeing wastewater regulating tank for treatment;

Step 3, a dyeing wastewater treatment method comprises the following steps:

step 3a, after being singly collected, the dyeing wastewater enters a dyeing wastewater regulating tank to regulate the water quality and the water quantity, then is pumped into a third pH regulating tank, sulfuric acid is added to regulate the pH value to 3-4, aeration and stirring are carried out, and effluent is discharged into a Fenton reaction tank;

Step 3b, respectively adding H2O2 and FeSO4 into the Fenton reaction tank to perform Fenton reaction, performing aeration stirring, and discharging effluent after Fenton reaction into a third pH callback tank;

Step 3c, adding NaOH into the third pH callback tank for aeration stirring, adjusting the pH value to 7-8, and discharging effluent into the third reduction reaction tank;

step 3d, adding a reducing agent NaHSO3 into the third first reduction reaction tank, stirring to control the oxidation-reduction potential to +/-150 mv, and enabling the effluent to enter a third rapid mixing tank;

Step 3e, adding coagulant polyaluminium chloride PAC into the third rapid mixing tank, aerating and stirring, coagulating suspended matters in the sewage into larger particles, and then discharging the sewage into the third slow mixing tank;

step 3f, adding a polymeric flocculant PAM into the third slow mixing tank, and stirring to form massive flocs by particles in water;

Step 3g, discharging the sewage of the third slow mixing tank into a third inclined tube sedimentation tank for gravity sedimentation, enabling the sedimented sludge to enter a mud bucket, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the concentration tank by a second chamber filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment;

Step 3h, discharging the supernatant of the third inclined tube sedimentation tank into a third intermediate tank, adding sulfuric acid, aerating and stirring, adjusting the pH value to 6.5-7.5, and discharging the effluent into an anaerobic tank in a biochemical system;

Step 3i, carrying out anaerobic reaction and stirring on wastewater in an anaerobic tank, then discharging anaerobic effluent into an anoxic tank for denitrification reaction and stirring, discharging effluent into an aerobic tank for oxidation and nitrification reaction, and pumping mixed liquor in the aerobic tank back to the anoxic tank for denitrification reaction;

step 3j, discharging the effluent of the aerobic tank into an MBR membrane tank, filtering the wastewater by an ultrafiltration membrane component, pumping the wastewater into an MBR water producing tank, intercepting sludge in the MBR membrane tank, and pumping the intercepted sludge back to an anaerobic tank, an anoxic tank and an aerobic tank;

Step 3k, adding sulfuric acid into the pH adjusting tank of the discharged water, aerating and stirring, adjusting the pH value to 3-4, and discharging the discharged water into the Fenton reaction tank of the discharged water;

step 3l, respectively adding H202 and FeSO4 into the discharged water Fenton reaction tank to perform Fenton reaction, and performing aeration stirring, wherein discharged water after Fenton reaction enters a discharged water pH callback tank;

Step 3m, adding NaOH into a discharged water pH callback tank, stirring by aeration, adjusting the pH value to 7-8, and then enabling the discharged water to enter a discharged water reduction reaction tank;

Step 3n, adding a reducing agent NaHSO3 into the discharged water reduction reaction tank, stirring to control the oxidation-reduction potential to +/-150 mv, and enabling the discharged water to enter a discharged water rapid mixing tank;

Step 3o, adding coagulant polyaluminium chloride PAC into the discharge water rapid mixing tank, aerating and stirring, coagulating suspended matters in the sewage into larger particles, and then discharging into the discharge water slow mixing tank;

Step 3p, adding a polymeric flocculant PAM into the discharged water slow mixing tank, stirring, forming massive flocs by particles in the water, discharging the water into a discharged water sedimentation tank for gravity sedimentation, periodically discharging the sedimented sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the sludge concentration tank by a second box filter press, and carrying out outward transportation on dry sludge, wherein the filtrate is discharged into a phosphorus-containing wastewater regulating tank for continuous treatment;

Step 3q, discharging supernatant of the discharged water sedimentation tank into a discharged water middle tank, lifting wastewater in the discharged water middle tank to a discharged water aeration biological denitrification filter, then, enabling effluent to enter the discharged water aeration biological denitrification filter, and then enabling effluent of the discharged water aeration biological nitrification filter to enter a discharged water tank;

and 3r, adding NaOH or H2SO4 into a water discharge pool, aerating and stirring, adjusting the pH value to 6-9, and discharging the effluent after reaching the standard.

Step 4, a treatment method of phosphorus-containing wastewater comprises the following steps:

step 4a, the phosphorus-containing wastewater is singly collected and discharged into a phosphorus-containing wastewater regulating tank to regulate the water quality and the water quantity, and then the wastewater in the phosphorus-containing wastewater regulating tank is pumped into a fourth pH regulating tank in an air floatation device;

Step 4b, adding NaOH into a fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and discharging effluent into a fourth dephosphorizing reaction tank in the air floatation device;

step 4c, adding a dephosphorizing agent into a fourth dephosphorizing reaction tank, stirring and reacting, and then discharging the wastewater into a fourth slow mixing tank in an air floatation device;

Step 4d, adding a polymeric flocculant PAM into the fourth slow mixing tank, stirring to perform flocculation reaction, discharging the wastewater into an air floatation tank in an air floatation device, forming scum by the flocs, scraping the scum into a scum tank, discharging sludge by gravity into a comprehensive sludge concentration tank, press-filtering the sludge in the comprehensive sludge concentration tank by a second box filter press, carrying out outward transport of dry sludge, continuously treating the filtrate in a phosphorus-containing wastewater regulation tank, and continuously performing dephosphorization reaction on the discharged water of the air floatation tank in a fourth pH regulation tank;

Step 4e, adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and discharging effluent into a fourth dephosphorization reaction tank;

step 4f, adding a dephosphorizing agent into the fourth dephosphorizing reaction tank for stirring reaction, and then discharging the wastewater into a fourth slow mixing tank;

Step 4g, adding a polymeric flocculant PAM into the fourth slow mixing tank, mechanically stirring, performing flocculation reaction, forming large-block flocs by particles in water, discharging wastewater into a fourth primary sedimentation tank for gravity sedimentation, periodically discharging the precipitated sludge into a sludge bucket, periodically discharging the sludge into a comprehensive sludge concentration tank, performing filter pressing on the sludge in the sludge concentration tank by a second chamber filter press, transporting dry sludge outwards, discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment, and discharging supernatant of the fourth primary sedimentation tank into a fourth pH regulating tank for continuous phosphorus removal reaction;

Step 4h, adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH to 9-10, and discharging the wastewater into a fourth quick mixing tank;

Step 4i, adding coagulant polyaluminium chloride PAC into the fourth rapid mixing tank, aerating and stirring, coagulating the precipitated precipitate into larger particles, and then discharging the wastewater into a fourth slow mixing tank;

Step 4j, adding a polymeric flocculant PAM into the fourth slow mixing tank, stirring, forming large-block flocs by particles in water, and then discharging the wastewater into a secondary sedimentation tank;

And 4k, carrying out gravity precipitation on the flocs in a secondary sedimentation tank, enabling the precipitated sludge to enter a sludge bucket, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the comprehensive sludge concentration tank through a second box type filter press, carrying out outward transportation on dry sludge, discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment, discharging supernatant of the secondary sedimentation tank into a fourth intermediate tank for transfer, and then pumping wastewater of the fourth intermediate tank into a third pH callback tank of a dyeing wastewater treatment system for continuous treatment.

Further, in steps 1b and 1f in the treatment method of nickel-containing wastewater, step 2b in the treatment method of inorganic wastewater, steps 3e and 3o in the treatment method of dyeing wastewater, and step 4i in the treatment method of phosphorus-containing wastewater, the adding amount of coagulant polyaluminium chloride PAC is 500-800 mg/L each time, and the stirring and mixing reaction time is 30min.

Further, in order to ensure flocculation effect and obtain ideal coagulation effect, stirring time is shortened within a proper range, in the steps 1c and 1G in the nickel-containing wastewater treatment method, in the step 2c in the inorganic wastewater treatment method and in the steps 3f and 3p in the dyeing wastewater treatment method, in the steps 4d, 4G and 4j in the phosphorus-containing wastewater treatment method, the adding amount of the polymeric flocculant PAM is 5-8 mg/L each time, meanwhile, stirring and mixing reaction time is 30min, and the average speed gradient G value is controlled to be 30-60 s < -1 >.

Further, in order to ensure the Fenton reaction effect, the addition amount of H202 in a Fenton reaction tank is 100-200 mg/L, the addition amount of FeSO4 is 200-300 mg/L, and the stirring and mixing reaction time is 1H.

Further, in order to increase the treatment efficiency of the biochemical system, the mixed solution in the aerobic tank is refluxed to the anoxic tank at a reflux ratio of 100-400%.

Further, in order to ensure the effect of the dephosphorization reaction and reduce the cost, the dephosphorization agents added in the fourth first dephosphorization reaction tank and the fourth second dephosphorization reaction tank are FeSO4, and the addition amounts are 80-100 mg/L.

Further, in order to effectively prevent the formation of scale and microorganism adhesion, the desalination rate and the water yield of the system are improved, and the adding amount of the scale inhibitor added into the third pipeline mixer is LTLD-RO scale inhibitor, which is 3-5 ppm.

The invention also provides an anodic oxidation wastewater treatment system for realizing the method, which comprises a nickel-containing wastewater treatment system, an inorganic wastewater treatment system, a dyeing wastewater treatment system, a discharge water system and a phosphorus-containing wastewater treatment system which are related;

The nickel-containing wastewater treatment system comprises a nickel-containing wastewater regulating tank, a first pH regulating tank, a first quick mixing tank, a first slow mixing tank, a first primary sedimentation tank, a nickel-containing sludge concentration tank, a first box filter press, a first pH regulating tank, a first quick mixing tank, a first slow mixing tank, a first inclined tube sedimentation tank, an intermediate clean water tank, a first quartz sand filter and an ion exchanger, wherein an outlet of the nickel-containing wastewater regulating tank is connected to the first pH regulating tank, an outlet of the first pH regulating tank is connected to the first quick mixing tank, an outlet of the first quick mixing tank is connected to the first slow mixing tank, an outlet of the first slow mixing tank is connected to the first primary sedimentation tank, an outlet of the first primary sedimentation tank is connected to the nickel-containing sludge concentration tank, and an outlet of the nickel-containing sludge concentration tank is connected to the first box filter press by a pump;

The inorganic wastewater treatment system comprises an inorganic wastewater regulating tank, a second first pH regulating tank, a second first rapid mixing tank, a second first slow mixing tank, a second first primary sedimentation tank, a comprehensive sludge concentration tank, an inorganic clean water tank and a reuse water system, wherein the reuse water system comprises an ion exchanger, a second first quartz sand filter, an activated carbon filter, a first pipeline mixer, a second pipeline mixer, a third pipeline mixer, a UF membrane system, a UF water producing tank, a first RO system, a first RO water producing tank, a second RO system and a pure water producing tank, the outlet of the inorganic wastewater regulating tank is connected to the second first pH regulating tank, the outlet of the second first pH regulating tank is connected to the second first rapid mixing tank, the outlet of the second first rapid mixing tank is connected to the second slow mixing tank, the outlet of the second slow mixing tank is connected to the second first primary sedimentation tank, the first outlet of the second primary sedimentation tank is connected to the comprehensive sludge concentration tank, the other outlet of the second primary sedimentation tank is connected to the inorganic clean water tank, the inorganic filter is connected to the first inlet of the inorganic clean water tank, the inorganic filter is connected to the first filter through the first filter, the UF filter is connected to the first filter, the first filter is connected to the first filter, the UF filter is connected to the inlet of the inorganic filter in turn, the first filter is connected to the first filter through the first filter, the UF filter is connected to the inlet of the inorganic filter, the other inlet of the UF water producing tank is connected to the outlet of the MBR water producing tank of the dyeing wastewater treatment system; the outlet of the UF water producing pool is connected to the primary RO system, the outlet of the primary RO system is connected to a dyeing wastewater regulating pool of the dyeing wastewater treatment system, and the other outlet of the primary RO system is connected to the secondary RO system;

The dyeing wastewater treatment system comprises a dyeing wastewater regulating tank, a third pH regulating tank, a Fenton reaction tank, a third pH callback tank, a fourth intermediate tank, a third reduction reaction tank, a third quick mixing tank, a third slow mixing tank, a third inclined tube sedimentation tank, a comprehensive sludge concentration tank, a third intermediate tank and a biochemical system, wherein the biochemical system comprises an anaerobic tank, an anoxic tank, an aerobic tank, an MBR membrane tank and an MBR production tank, the outlet of the dyeing wastewater regulating tank is connected to the third pH regulating tank, the outlet of the third pH regulating tank is connected to the Fenton reaction tank, the outlet of the Fenton reaction tank is connected to the inlet of the third pH callback tank, the other inlet of the third pH callback tank is connected to the outlet of the fourth intermediate tank of the phosphorus-containing wastewater treatment system, the outlet of the third pH callback tank is connected to the reduction reaction tank, the outlet of the reduction reaction tank is connected to the third quick mixing tank, the outlet of the third quick mixing tank is connected to the third anoxic tank, the outlet of the aerobic tank is connected to the anoxic tank, the outlet of the first inclined tube sedimentation tank is connected to the anoxic tank, the first anoxic tank is connected to the outlet of the anoxic tank, the first anaerobic tank is connected to the anoxic tank, the oxygen-back-to the anaerobic tank is connected to the outlet of the anoxic tank, the oxygen-back tank is connected to the other anaerobic tank, the oxygen-back-mixing tank is connected to the outlet of the anaerobic tank, the oxygen-back tank is connected to the other oxygen pump, the oxygen-oxygen tank is connected to the outlet of the anaerobic tank, the oxygen-oxygen pump is connected to the outlet of the anaerobic tank, the oxygen tank is connected to the outlet of the anaerobic tank and the other outlet of the anaerobic tank is connected to the oxygen pump and the outlet of the intermediate tank and the oxygen tank respectively, the system comprises an MBR water producing tank, an inorganic wastewater treatment system, a water discharging system and a water discharging system, wherein the other outlet is connected to the MBR water producing tank;

The system comprises a discharge water pH adjusting tank, a discharge water Fenton reaction tank, a discharge water pH callback tank, a discharge water reduction reaction tank, a discharge water quick mixing tank, a discharge water slow mixing tank, a discharge water sedimentation tank, a comprehensive sludge concentration tank, a discharge water intermediate tank, a discharge water aeration biological denitrification tank, a discharge water aeration biological nitrification tank and a discharge water tank, wherein the outlet of the discharge water pH adjusting tank is connected to the discharge water Fenton reaction tank, the outlet of the discharge water Fenton reaction tank is connected to the discharge water pH callback tank, the outlet of the discharge water pH callback tank is connected to the discharge water reduction reaction tank, the outlet of the discharge water reduction reaction tank is connected to the discharge water quick mixing tank, the outlet of the discharge water quick mixing tank is connected to the discharge water slow mixing tank, the outlet of the discharge water slow mixing tank is connected to the discharge water sedimentation tank, the outlet of the discharge water sedimentation tank is connected to the comprehensive sludge concentration tank, the other outlet of the discharge water sedimentation tank is connected to the discharge water intermediate tank;

The system comprises a phosphorus-containing wastewater treatment system, a wastewater treatment system and a wastewater treatment system, wherein the phosphorus-containing wastewater treatment system comprises a phosphorus-containing wastewater regulating tank, an air floatation device, a floating slag tank, a comprehensive sludge concentration tank, a fourth second pH regulating tank, a fourth second dephosphorization reaction tank, a fourth second slow mixing tank, a fourth first primary sedimentation tank, a fourth third pH regulating tank, a fourth first fast mixing tank, a fourth slow mixing tank, a second intermediate tank, wherein the air floatation device comprises a fourth first pH regulating tank, a fourth first dephosphorization reaction tank, a fourth first slow mixing tank and an air floatation tank, the outlet of the phosphorus-containing wastewater regulating tank is connected to the fourth first pH regulating tank of the air floatation device, the outlet of the fourth first pH regulating tank is connected to the fourth first dephosphorization reaction tank, the outlet of the fourth first dephosphorization reaction tank is connected to the air floatation tank, the outlet of the fourth third fast mixing tank is connected to the scum tank, the first outlet of the fourth slag tank is connected to the comprehensive sludge concentration tank, the other outlet of the fourth slow mixing tank is connected to the fourth second intermediate tank, the outlet of the fourth second slow mixing tank is connected to the fourth slow mixing tank, the outlet of the fourth second sedimentation tank is connected to the fourth slow mixing tank, the fourth sedimentation tank is connected to the fourth slow mixing tank, the outlet of the fourth slow mixing tank is connected to the fourth slow mixing tank, the fourth outlet of the fourth mixing tank is connected to the fourth slow mixing tank;

The outlet of the comprehensive sludge concentration tank connected with the inorganic wastewater treatment system, the dyeing wastewater treatment system, the discharge water system and the phosphorus-containing wastewater treatment system is connected to a second chamber filter press by a pump, and the water outlet of the second chamber filter press is connected to a phosphorus-containing wastewater regulating tank.

Further, in order to facilitate control of the pH value and the pH precision and ensure the neutralization effect of acid and alkali, the first pH adjusting tank, the first second pH adjusting tank, the middle clean water tank, the second pH adjusting tank, the first pipeline mixer, the third pH adjusting tank, the third pH callback tank, the discharge water pH adjusting tank, the discharge water pH callback tank, the fourth pH adjusting tank, the fourth second pH adjusting tank and the fourth pH adjusting tank are all provided with pH on-line control devices.

Further, in order to facilitate automatic control and detection of oxidation-reduction potential values in the wastewater, an ORP on-line control device is arranged in each of the second pipeline mixer, the third first reduction reaction tank, the discharged water callback tank and the discharged water reduction reaction tank.

The invention will be described in more detail below with reference to the drawings and examples.

Drawings

FIG. 1 is a schematic diagram of the overall flow of an anodic oxidation wastewater treatment system according to the present invention.

FIG. 2 is a schematic flow chart of a nickel-containing wastewater treatment system in the invention.

FIG. 3 is a schematic flow chart of an inorganic wastewater treatment system in the invention.

FIG. 4 is a schematic flow chart of a dyeing wastewater treatment system in the invention.

FIG. 5 is a schematic flow chart of the effluent treatment system according to the present invention.

FIG. 6 is a schematic flow chart of a phosphorus-containing wastewater treatment system in the invention.

Detailed Description

An anodic oxidation wastewater treatment method and system as shown in fig. 1, the specific embodiment is as follows:

the waste water generated by the anodic oxidation production line is mainly divided into four types of nickel-containing waste water, inorganic waste water, dyeing waste water and phosphorus-containing waste water, and the four types of waste water are required to be treated respectively, discharged and recycled uniformly.

The nickel-containing wastewater mainly comes from hole sealing waste liquid and post-cleaning nickel-containing wastewater, and the main pollution factors are nickel acetate, aluminum, COD, SS and the like.

As shown in fig. 2, the treatment method of nickel-containing wastewater comprises the following steps:

Step 1a, after nickel-containing wastewater discharged from a workshop is singly collected, discharging the wastewater into a nickel-containing wastewater regulating tank to regulate the water quality and water quantity, pumping the wastewater into a first pH regulating tank by using a lifting pump, adding NaOH to regulate the pH value to 9-11 in order to ensure the optimal pH value of flocculation reaction, automatically controlling the adding quantity of the NaOH by a pH on-line control device arranged in the first pH regulating tank, carrying out aeration stirring and mixing reaction for 30 minutes, and separating nickel ions and hydroxide ions in the wastewater to form nickel hydroxide precipitates;

Step 1b, discharging the wastewater into a first quick mixing tank, adding a coagulant polyaluminium chloride (PAC), and carrying out aeration stirring for 30 minutes, wherein the addition amount of PAC is 500-800 mg/L, and carrying out aeration stirring to fully mix the wastewater for 30 minutes, so that the precipitated nickel hydroxide precipitate is coagulated into larger particles;

Step 1c, then discharging the wastewater into a first slow mixing tank, adding a polymeric flocculant PAM, mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the mixing stirring intensity controls the average speed gradient G value to be 30-60 s < -1 >, and the particles in the water form massive flocs under the adsorption net capturing action of the PAM;

Step 1d, discharging the sewage in the first primary sedimentation tank into the first primary sedimentation tank for gravity sedimentation, and periodically discharging the sedimented sludge into a nickel-containing sludge concentration tank after the sedimented sludge enters a mud bucket of the first primary sedimentation tank;

step 1e, discharging the supernatant of the first primary sedimentation tank into a first secondary pH adjustment tank, adding NaOH again to adjust the pH value to 9-11, and performing aeration stirring reaction for 30 minutes, wherein the adding amount of the NaOH is automatically controlled by a pH on-line control device arranged in the first secondary pH adjustment tank, and nickel ions and hydroxide ions in the wastewater form nickel hydroxide precipitate to be separated out;

step 1f, discharging the wastewater into a first secondary rapid mixing tank, adding a coagulant polyaluminium chloride (PAC), and carrying out aeration stirring for 30 minutes, wherein the addition amount of PAC is 500-800 mg/L, and carrying out aeration stirring to fully mix the wastewater for 30 minutes, so that the precipitated nickel hydroxide precipitate is coagulated into larger particles;

step 1G, discharging the wastewater from the first secondary rapid mixing tank into the first secondary slow mixing tank, adding a polymeric flocculant PAM, mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the mixing stirring intensity controls the average speed gradient G value to be 30-60 s < -1 >, and the particles in the water form large-block flocs under the adsorption net capturing action of the PAM;

Step 1h, discharging the wastewater of the first second slow mixing tank into a first inclined tube sedimentation tank for gravity sedimentation, enabling the sedimentated sludge to enter a sludge bucket of the first inclined tube sedimentation tank, periodically discharging the sedimentated sludge into a nickel-containing sludge concentration tank, carrying out filter pressing on the sludge in the nickel-containing sludge concentration tank through a first box filter press, carrying out outward transport on dry sludge, and discharging filtrate into a nickel-containing wastewater regulating tank for retreatment;

Step 1i, discharging the supernatant of the first inclined tube sedimentation tank into a middle clean water tank, adding sulfuric acid into the middle clean water tank to adjust the pH value to 6.5-7.5, wherein the adding amount of the sulfuric acid is automatically controlled by a pH on-line control device arranged in the middle clean water tank, and carrying out aeration stirring reaction for 30 minutes. Pumping the wastewater of the middle clean water tank into a first quartz sand filter by using a lift pump, if the content of nickel ions detected by the first quartz sand filter is lower, directly discharging the wastewater into an inorganic clean water tank in an inorganic wastewater treatment system for continuous treatment, and if the content of nickel ions detected by the first quartz sand filter is higher, discharging the wastewater into the inorganic clean water tank in the inorganic wastewater treatment system for continuous treatment after being treated by using an ion exchanger, and pumping the water of the inorganic clean water tank into a reuse water system by using the lift pump for continuous treatment.

The inorganic wastewater has low organic matter content and small aluminum content because the cleaning water source is pure water.

As shown in fig. 3, the method for treating inorganic wastewater comprises:

Step 2a, inorganic wastewater is singly collected and then discharged into an inorganic wastewater regulating tank to regulate the water quality and the water quantity, the wastewater is pumped into a second pH regulating tank by a lifting pump, naOH is added to regulate the pH value to 8.5-9 in order to ensure the optimal pH value of flocculation reaction, the adding amount of the NaOH is automatically controlled by a pH on-line control device arranged in the second pH regulating tank, aeration and stirring are carried out for 30 minutes, and aluminum ions and hydroxyl ions in the wastewater form aluminum hydroxide precipitate to be separated out;

Step 2b, discharging the wastewater of the second pH adjusting tank into a second rapid mixing tank, adding a coagulant polyaluminium chloride PAC, performing aeration stirring reaction for 30 minutes, wherein the addition amount of PAC is 500-800 mg/L, and coagulating the precipitated precipitate into larger particles;

Step 2c, then discharging the wastewater into a second slow mixing tank, adding a polymeric flocculant PAM, mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the mixing stirring intensity controls the average speed gradient G value to be 30-60 s < -1 >, and the particles in the water form massive flocs under the adsorption net capturing action of the PAM;

Step 2d, discharging the sewage in the second slow mixing tank into a second primary sedimentation tank for gravity sedimentation, discharging the precipitated sludge into a sludge bucket of the second primary sedimentation tank periodically, discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the concentration tank by a second box type filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment;

and 2e, discharging the supernatant fluid of the second primary sedimentation tank into an inorganic clean water tank, pumping the wastewater of the inorganic clean water tank into a second quartz sand filter of a reuse water system by a lifting pump for treatment, treating the wastewater by an activated carbon filter, and discharging the wastewater filtered by the activated carbon filter into a UF membrane system for treatment. In order to ensure the optimal pH value of membrane treatment, a first pipeline mixer for fully mixing sulfuric acid and wastewater is arranged on a water inlet pipeline of a UF membrane system, a second pipeline mixer for fully mixing sodium bisulphite and wastewater is used for adding a reducing agent, and a scale inhibitor can be used, wherein the main components of the scale inhibitor are organic dispersions, organic complexes, monoatomic oxygen hydroxyl polymers and the like, the adding amount of the scale inhibitor is 3-5 ppm, the scale inhibitor is fully mixed with the wastewater, a third pipeline mixer for ensuring the normal operation of a subsequent RO system is used for ensuring that the pH value of the third pipeline mixer before the UF membrane system is treated reaches 6.5-7.5, the oxidation-reduction potential of the reducing agent is controlled to be +/-150 mv, the adding amount of the sulfuric acid is automatically controlled by a pH on-line control device arranged on the first pipeline mixer, and the adding amount of the reducing agent is automatically controlled by an ORP on-line control device arranged on the second pipeline mixer;

Step 2f, discharging the water discharged from the UF water producing tank into a first-stage RO system, discharging the water produced by the first-stage RO system into a first-stage RO water producing tank, and discharging the concentrated water produced by the first-stage RO system into a dyeing wastewater regulating tank of a dyeing wastewater treatment system for continuous treatment;

the dyeing wastewater mainly comes from dyeing waste liquid and dyed washing wastewater, and main pollutants of the dyeing wastewater are COD, chromaticity and SS.

As shown in fig. 4 and 5, the treatment method of dyeing wastewater comprises:

And 3a, independently collecting the dyeing wastewater, then enabling the dyeing wastewater to enter a dyeing wastewater regulating tank, wherein the dyeing wastewater regulating tank is used for receiving the dyeing wastewater discharged from a production line and concentrated water generated by primary RO, and pumping the wastewater into a third pH regulating tank by using a lifting pump after fully regulating the water quality and the water quantity. In order to ensure the optimal pH value of the subsequent Fenton reaction, adding sulfuric acid into a third pH adjusting tank to adjust the pH value to 3-4, wherein the adding amount of the sulfuric acid is automatically controlled by a pH on-line control device arranged in the third pH adjusting tank, and after aeration stirring reaction is carried out for 30 minutes, discharging effluent into a Fenton reaction tank;

Step 3b, respectively adding H2O2 and FeSO4 into a Fenton reaction tank to perform Fenton reaction, wherein the addition amount of H202 is 100-200 mg/L, the addition amount of FeSO4 is 200-300 mg/L, and after the Fenton reaction tank is subjected to aeration stirring reaction for 1 hour, discharging effluent after the Fenton reaction into a third pH callback tank;

Step 3c, adding NaOH into the third pH callback tank, and adjusting the pH value to 7-8, wherein the adding amount of the NaOH is automatically controlled by a pH on-line control device arranged in the third pH callback tank, and after aeration stirring reaction is carried out for 30 minutes, discharging effluent into a third reduction reaction tank;

In step 3d, the third reduction reaction tank is used for carrying out reduction reaction on the redundant oxidant, so that the influence of the oxidant on subsequent reactions is reduced. Adding a reducing agent NaHSO3 into the third reduction reaction tank, mechanically stirring and reacting for 30min to control the oxidation-reduction potential to +/-150 mv, controlling the adding amount of the reducing agent by an ORP on-line control device arranged in the third reduction reaction tank, controlling the average speed gradient G value to be 30-60 s < -1 > by the mixing and stirring intensity, and then enabling effluent to enter a third rapid mixing tank;

Step 3e, adding coagulant polyaluminium chloride PAC with the addition amount of 500-800 mg/L into the third rapid mixing tank, performing aeration stirring reaction for 30 minutes, coagulating suspended matters in the sewage into larger particles, and then discharging the sewage into the third slow mixing tank;

Step 3f, adding a polymeric flocculant PAM into the third slow mixing tank, wherein the addition amount of the PAM is 5-8 mg/L, mechanically stirring for 30 minutes, controlling the average speed gradient G value to be 30-60 s < -1 >, and forming massive flocs by the particles in water under the adsorption net capturing action;

Step 3g, discharging the sewage of the third slow mixing tank into a third inclined tube sedimentation tank for gravity sedimentation, enabling the sedimented sludge to enter a mud bucket, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the concentration tank through a second chamber filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank of a phosphorus-containing wastewater treatment system for continuous treatment;

Step 3h, discharging the supernatant of the third inclined tube sedimentation tank into a third intermediate tank, adding sulfuric acid, aerating, stirring and reacting for 30 minutes, adjusting the pH value to 6.5-7.5, and discharging the effluent into an anaerobic tank in a biochemical system;

and 3i, the biochemical system adopts an AAO+MBR process, namely a hydrolysis acidification process, an anoxic process, an aerobic process and an MBR process, and the wastewater entering the biochemical system firstly enters an anaerobic tank for anaerobic reaction, wherein a submersible mixer is arranged in the anaerobic tank, so that sludge deposition in the anaerobic tank can be prevented. And then the anaerobic effluent is discharged into an anoxic tank for denitrification reaction, and a submersible stirrer is arranged in the anoxic tank, so that sludge deposition at the bottom can be prevented, and the denitrification efficiency can be improved. And then the effluent is discharged into an aerobic tank for oxidation and nitration, and the mixed solution in the aerobic tank is pumped back to an anoxic tank for continuous denitrification. In order to improve the treatment effect of the biochemical system, the mixed solution in the aerobic tank flows back to the anoxic tank at a reflux ratio of 100-400%.

And 3j, discharging the effluent of the aerobic tank into an MBR membrane tank to stay for 30-60 min, wherein an immersed ultrafiltration membrane component is arranged in the MBR membrane tank in order to improve the membrane filtration efficiency and reduce the cost. After the wastewater is filtered by the immersed ultrafiltration membrane component, the wastewater is pumped into an MBR (Membrane biological reactor) water producing tank, sludge is trapped in the MBR membrane tank, and the trapped sludge is pumped back to an anaerobic tank, an anoxic tank and an aerobic tank, wherein one part of water in the MBR water producing tank is discharged into a UF water producing tank of an inorganic wastewater treatment system for recycling water treatment, and the other part of water in the MBR water producing tank is discharged into a discharged water pH adjusting tank of a discharged water system for continuous treatment;

Step 3k, adding sulfuric acid into the discharged water pH adjusting tank, aerating and stirring for 30 minutes, adjusting the pH value to 3-4 in order to ensure the optimal pH value of the subsequent Fenton reaction, automatically controlling the adding amount of H2S04 by a pH on-line control device arranged in the discharged water pH adjusting tank, and discharging the discharged water into the discharged water Fenton reaction tank;

Step 3L, respectively adding H202 and FeSO4 into a Fenton reaction tank for Fenton reaction, and performing aeration stirring reaction for 1 hour, wherein the addition amount of H202 is 100-200 mg/L, the addition amount of FeSO4 is 200-300 mg/L, and the effluent after Fenton reaction is discharged into a pH callback tank of the discharged water;

step 3m, adding NaOH into the discharged water pH callback tank, aerating, stirring and reacting for 30 minutes, adjusting the pH value to 7-8, automatically controlling the adding amount of the NaOH by a pH on-line control device arranged in the discharged water pH callback tank, and discharging the discharged water into a discharged water reduction reaction tank;

Step 3n, the effect of the discharged water reduction reaction tank is to carry out reduction reaction on redundant oxidant, the influence of the oxidant on subsequent reaction is reduced, a reducing agent NaHSO3 is added into the discharged water reduction reaction tank and is mechanically stirred, so that the oxidation-reduction potential is controlled to be +/-150 mv, the addition amount of the reducing agent is automatically controlled by an ORP on-line control device arranged in the discharged water reduction reaction tank, the average speed gradient G value is controlled to be 30-60 s < -1 >, and then discharged water is discharged into a discharged water rapid mixing tank;

step 3o, adding coagulant polyaluminium chloride (PAC) into the discharge water rapid mixing tank, aerating and stirring for 30 minutes, wherein the PAC addition amount is 500-800 mg/L, coagulating suspended substances in the sewage into larger particles, and then discharging the sewage into the discharge water slow mixing tank;

Step 3p, adding a polymeric flocculant PAM into the discharged water slow mixing tank, mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the mixing stirring intensity controls the average speed gradient G value to be 30-60 s < -1 >, particles in water form large-block flocs, then discharging water into a discharged water sedimentation tank for gravity sedimentation, discharging the sedimented sludge into a sludge bucket of the discharged water sedimentation tank, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the sludge concentration tank by a second chamber filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank of a phosphorus-containing wastewater treatment system for continuous treatment;

Step 3q, discharging supernatant of the discharged water sedimentation tank into a discharged water intermediate tank, wherein the main function of the discharged water intermediate tank is to transfer wastewater, pumping the wastewater in the discharged water intermediate tank into a discharged water aeration biological denitrification filter (a discharged water BAF-DN tank) by using a lifting pump, keeping the retention time for 3h, then, enabling the discharged water to enter the discharged water aeration biological nitrification filter (the discharged water BAF-CN tank), keeping the retention time for 3h, and after COD (chemical oxygen demand) removal and denitrification, enabling the discharged water of the discharged water aeration biological nitrification filter to enter a discharged water tank;

And 3r, adding NaOH or H2SO4 into the water discharge pond, performing aeration stirring reaction for 30 minutes, adjusting the pH value to 6-9, automatically controlling the adding amount of the NaOH or H2S04 by a pH on-line control device arranged in the water discharge pond, and discharging the effluent after reaching the standard.

The phosphorus-containing wastewater mainly originates from the chemical-polished cleaning wastewater, and the main pollutants of the phosphorus-containing wastewater include COD, phosphorus, SS and the like.

As shown in fig. 6, the treatment method of the phosphorus-containing wastewater comprises the following steps:

And 4a, separately collecting the phosphorus-containing wastewater, discharging the wastewater into a phosphorus-containing wastewater regulating tank to regulate the water quality and the water quantity, and pumping the wastewater in the phosphorus-containing wastewater regulating tank into a fourth pH regulating tank in an air floatation device by using a lifting pump, wherein the fourth pH regulating tank, a fourth dephosphorization reaction tank, a fourth slow mixing tank and the air floatation tank are arranged on the air floatation device.

Step 4b, adding NaOH into the fourth pH adjusting tank, aerating and stirring for 30 minutes, adjusting the pH value to 9-10, automatically controlling the adding amount of the NaOH by a pH on-line control device arranged in the fourth pH adjusting tank, and discharging the effluent into a fourth dephosphorization reaction tank in the air floatation device;

Step 4c, adding a dephosphorizing agent into the fourth dephosphorizing reaction tank, mixing and stirring for 30 minutes, wherein in order to ensure the effect of dephosphorizing reaction and reduce the cost, the dephosphorizing agent added into the fourth dephosphorizing reaction tank is FeSO4, the adding amount of the dephosphorizing agent is 80-100 mg/L, the FeSO4 has the functions of coagulation and dephosphorization, ferrous phosphate precipitation is formed in the fourth dephosphorizing reaction tank after the reaction, and then the wastewater is discharged into a fourth slow mixing tank in an air floatation device;

And 4d, adding a polymeric flocculant PAM into the fourth slow mixing pool, mechanically stirring for 30 minutes, performing flocculation reaction, wherein the addition amount of the PAM is 5-8 mg/L, the average speed gradient G value is controlled to be 30-60 s < -1 >, under the adsorption net capturing action of the PAM, the particles in the water form massive flocs, then discharging the wastewater into an air floatation pool in an air floatation device, and air is introduced into the water by adopting dissolved air floatation to generate fine bubbles, so that fine phosphorus-containing suspended matters in the water adhere to the air bubbles and float to the water surface together with the bubbles to form scum. Scraping scum into a scum pool by using a scum scraper, discharging sludge into a comprehensive sludge concentration pool by gravity, carrying out filter pressing on sludge in the comprehensive sludge concentration pool by using a second chamber filter press, carrying out outward transportation on dry sludge, enabling filtrate to flow into a phosphorus-containing wastewater regulating pool for continuous treatment, and discharging effluent of an air floatation pool into a fourth pH regulating pool for continuous phosphorus removal reaction;

Step 4e, in order to ensure the optimal pH value of the dephosphorization reaction, naOH is added into a fourth pH adjusting tank and is aerated and stirred for 30 minutes, the pH value is adjusted to 9-10, the addition amount of the NaOH is automatically controlled by a pH on-line control device arranged in the fourth pH adjusting tank, and then effluent is discharged into the fourth dephosphorization reaction tank;

Step 4f, adding a dephosphorizing agent into a fourth dephosphorizing reaction tank, wherein in order to ensure the effect of dephosphorizing reaction and reduce the cost, the dephosphorizing agent added into the fourth dephosphorizing reaction tank is FeSO4, the adding amount of the dephosphorizing agent is 80-100 mg/L, the FeSO4 has the functions of coagulation and dephosphorizing, ferrous phosphate precipitation is formed in the fourth dephosphorizing reaction tank after the reaction, and then the wastewater is discharged into a fourth slow mixing tank;

Step 4G, adding a polymeric flocculant PAM into a fourth slow mixing tank, mechanically stirring and reacting for 30 minutes to perform flocculation reaction, wherein the addition amount of the PAM is 5-8 mg/L, the mixing and stirring intensity controls the average speed gradient G value to be 30-60 s < -1 >, particles in water form large-block flocs, then, discharging wastewater into a fourth primary sedimentation tank to perform gravity sedimentation, discharging the settled sludge into a fourth primary sedimentation tank mud bucket periodically, discharging the sludge in the sludge concentration tank into a comprehensive sludge concentration tank, performing filter pressing through a second box filter press, performing outward transport of dry sludge, discharging filtrate into a phosphorus-containing wastewater regulating tank of a phosphorus-containing wastewater treatment system, and continuously performing dephosphorization reaction on supernatant fluid of the fourth primary sedimentation tank;

Step 4h, in order to ensure the optimal pH value of flocculation reaction, naOH is added into a fourth pH adjusting tank, aeration stirring is carried out for 30 minutes, the pH value is adjusted to 9-10, the adding amount of the NaOH is automatically controlled by a pH on-line control device arranged in the fourth pH adjusting tank, and then wastewater is discharged into a fourth quick mixing tank;

Step 4i, adding a coagulant polyaluminium chloride (PAC) into the fourth rapid mixing tank, aerating and stirring for 30 minutes, wherein the addition amount of the PAC is 500-800 mg/L, coagulating the precipitated precipitate into larger particles, and then discharging the wastewater into a fourth slow mixing tank;

step 4j, adding a polymeric flocculant PAM into the fourth slow mixing tank, mechanically stirring and reacting for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the mixing and stirring intensity controls the average speed gradient G value to be 30-60 s < -1 >, particles in water form large-block flocs, and then discharging the wastewater into a secondary sedimentation tank;

and 4k, carrying out gravity precipitation on the flocs in a secondary sedimentation tank, enabling the precipitated sludge to enter a sludge hopper of the secondary sedimentation tank, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the comprehensive sludge concentration tank through a second box type filter press, carrying out outward transportation on dry sludge, discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment, transferring supernatant of the secondary sedimentation tank into a fourth intermediate tank, keeping the residence time for 1h, and then pumping wastewater of the fourth intermediate tank into a third pH callback tank of a dyeing wastewater treatment system for treatment through a lifting pump.

After the nickel-containing wastewater treatment system, the inorganic wastewater treatment system, the dyeing wastewater treatment system, the discharge water system and the phosphorus-containing wastewater treatment system are mutually related, anodic oxidation wastewater on a production line can be fully circulated and purified, purified produced water can be discharged up to standard or recycled, and meanwhile, the phosphorus-removing agent FeSO4 added in the phosphorus-containing wastewater treatment step has the functions of coagulation and phosphorus removal, so that the problem that the subsequent membrane treatment is affected by scaling of produced water calcium salt is avoided, and the cost is saved.

While the invention has been described above with reference to the accompanying drawings, it is to be understood that the invention is not limited to the details of the foregoing description, but is intended to cover various modifications of the invention, including the principles and teachings of the invention, as defined in the appended claims, or any other application of such modifications and variations, as may be desired.

Claims

1. The anodic oxidation wastewater treatment method comprises nickel-containing wastewater, inorganic wastewater, dyeing wastewater and phosphorus-containing wastewater, and is characterized by comprising the following steps:

(1) The method for treating nickel-containing wastewater comprises the following steps:

(1a) Discharging nickel-containing wastewater into a nickel-containing wastewater regulating tank to regulate the water quality and the water quantity, pumping into a first pH regulating tank, adding NaOH, aerating and stirring, regulating the pH value to 9-11, and separating nickel ions and hydroxide ions in the wastewater to form nickel hydroxide precipitate;

(1b) Discharging the wastewater into a first quick mixing tank, adding a coagulant polyaluminium chloride PAC, performing aeration stirring, and coagulating the separated precipitate into larger particles;

(1c) Then the wastewater is discharged into a first slow mixing tank, a polymeric flocculant PAM is added for stirring, and particles in the water form large-scale flocs;

(1d) Discharging sewage in the first primary sedimentation tank into a first slow mixing tank for gravity sedimentation, and periodically discharging the sedimented sludge into a sludge bucket into a nickel-containing sludge concentration tank;

(1e) Discharging the supernatant of the first primary sedimentation tank into a first pH adjusting tank, adding NaOH again, aerating and stirring, adjusting the pH value to 9-11, and separating nickel ions and hydroxyl ions in the wastewater to form nickel hydroxide precipitate;

(1f) Discharging the wastewater into a first secondary rapid mixing tank, adding a coagulant polyaluminium chloride PAC, and performing aeration stirring to coagulate the separated precipitate into larger particles;

(1g) Discharging the wastewater from the first secondary rapid mixing tank into the first secondary slow mixing tank, adding a polymeric flocculant PAM, stirring, and forming massive flocs by particles in the water under the action of adsorption net capturing;

(1h) Discharging the wastewater of the first secondary mixing tank into a first inclined tube sedimentation tank for gravity sedimentation, enabling the precipitated sludge to enter a sludge bucket, discharging the sludge into a nickel-containing sludge concentration tank periodically, carrying out filter pressing on the sludge in the nickel-containing sludge concentration tank through a first box filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a nickel-containing wastewater regulating tank for retreatment;

(1i) Discharging supernatant of the first one-to-one inclined tube sedimentation tank into an intermediate clean water tank, adding sulfuric acid into the intermediate clean water tank to adjust the pH value to 6.5-7.5, aerating and stirring, pumping wastewater into a first one-to-one quartz sand filter for treatment, and directly discharging effluent of the first one-to-one quartz sand filter into an inorganic clean water tank in an inorganic wastewater treatment system if the content of detected nickel ions is lower;

(2) The method for treating the inorganic wastewater comprises the following steps:

(2a) The inorganic wastewater is singly collected and discharged into an inorganic wastewater regulating tank to regulate the water quality and the water quantity, then the wastewater is pumped into a second pH regulating tank, naOH is added for aeration and stirring, the pH value is regulated to 8.5-9, and aluminum ions and hydroxide ions in the wastewater form aluminum hydroxide precipitate to be separated out;

(2b) Discharging the wastewater into a second rapid mixing tank, adding a coagulant polyaluminium chloride PAC, performing aeration stirring, and coagulating the separated precipitate into larger particles;

(2c) Then discharging the wastewater into a second slow mixing pool, adding a polymeric flocculant PAM, stirring, and forming large-block flocs by particles in the water;

(2d) Discharging sewage in the second slow mixing tank into a second primary sedimentation tank for gravity sedimentation, discharging the precipitated sludge into a sludge bucket periodically, discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the comprehensive sludge concentration tank by a second chamber filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank for treatment;

(2e) Discharging supernatant of the second primary sedimentation tank into an inorganic clean water tank, pumping wastewater of the inorganic clean water tank into a second quartz sand filter of a reuse water system for treatment, treating the wastewater through an activated carbon filter, and discharging the filtered wastewater into a UF membrane system for treatment through a pipeline; adding sulfuric acid to a water inlet pipeline of a UF membrane system to adjust the pH value through a first pipeline mixer, adding a reducing agent sodium bisulphite to adjust the oxidation-reduction potential through a second pipeline mixer, adding a scale inhibitor through a third pipeline mixer to enable the pH value of a water body to reach 6.5-7.5 before the UF membrane system is treated, and controlling the oxidation-reduction potential to be +/-150 mv;

(2f) Discharging the water discharged from the UF water producing tank into a first-stage RO system, discharging the water produced by the first-stage RO system into a first-stage RO water producing tank, and discharging the concentrated water produced by the first-stage RO system into a dyeing wastewater regulating tank for treatment;

(3) The method for treating dyeing wastewater comprises the following steps:

(3a) The dyeing wastewater is singly collected and then enters a dyeing wastewater regulating tank to regulate the water quality and the water quantity, then is pumped into a third pH regulating tank, sulfuric acid is added to regulate the pH value to 3-4, aeration and stirring are carried out, and effluent is discharged into a Fenton reaction tank;

(3b) H ₂O₂ and FeSO ₄ are respectively added into the Fenton reaction tank to carry out Fenton reaction, aeration and stirring are carried out, and effluent after Fenton reaction is discharged into a third pH callback tank;

(3c) Adding NaOH into the third pH callback tank for aeration stirring, adjusting the pH value to 7-8, and discharging effluent into the third reduction reaction tank;

(3d) Adding a reducing agent NaHSO ₃ into the third reduction reaction tank, stirring to control the oxidation-reduction potential to +/-150 mv, and enabling the effluent to enter a third rapid mixing tank;

(3e) Adding coagulant polyaluminium chloride PAC into the third rapid mixing tank, aerating and stirring, coagulating suspended matters in the sewage into larger particles, and then discharging the sewage into the third slow mixing tank;

(3f) Adding a polymeric flocculant PAM into the third slow mixing tank, and stirring to form large-block flocs by particles in water;

(3g) Discharging the sewage of the third slow mixing tank into a third inclined tube sedimentation tank for gravity sedimentation, enabling the sedimented sludge to enter a mud bucket, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the concentration tank by a second chamber filter press, carrying out outward transportation on dry sludge, and discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment;

(3h) Discharging the supernatant of the third inclined tube sedimentation tank into a third intermediate tank, adding sulfuric acid, aerating and stirring, adjusting the pH value to 6.5-7.5, and discharging the effluent into an anaerobic tank in a biochemical system;

(3i) Carrying out anaerobic reaction and stirring on wastewater in an anaerobic tank, then discharging anaerobic effluent into an anoxic tank for denitrification reaction and stirring, discharging effluent into an aerobic tank for oxidation and nitrification reaction, and pumping mixed liquor in the aerobic tank back to the anoxic tank for denitrification reaction;

(3j) The effluent of the aerobic tank is discharged into an MBR membrane tank, the wastewater is pumped into an MBR water producing tank after being filtered by an ultrafiltration membrane component, and the sludge is trapped in the MBR membrane tank, and the trapped sludge is pumped back to an anaerobic tank, an anoxic tank and an aerobic tank;

(3k) Adding sulfuric acid into a pH adjusting tank of the discharged water, aerating and stirring, adjusting the pH value to 3-4, and discharging the discharged water into a Fenton reaction tank of the discharged water;

(3 l) respectively adding H ₂O₂ and FeSO ₄ into a discharged water Fenton reaction tank to perform Fenton reaction, and performing aeration stirring, wherein discharged water after Fenton reaction enters a discharged water pH callback tank;

(3 m) adding NaOH into a discharged water pH callback tank, stirring by aeration, adjusting the pH value to 7-8, and then enabling the discharged water to enter a discharged water reduction reaction tank;

(3 n) adding a reducing agent NaHSO ₃ into the discharged water reduction reaction tank, stirring to control the oxidation-reduction potential to +/-150 mV, and enabling the discharged water to enter a discharged water rapid mixing tank;

(3 o) adding coagulant polyaluminium chloride PAC into the discharge water rapid mixing tank, aerating and stirring, coagulating suspended matters in the sewage into larger particles, and then discharging into the discharge water slow mixing tank;

(3 p) adding a polymeric flocculant PAM into the discharged water slow mixing tank, stirring, forming large-block flocs by particles in the water, discharging the water into a discharged water sedimentation tank for gravity sedimentation, periodically discharging the sedimented sludge into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the sludge concentration tank by a second box filter press, and carrying out outward transportation on dry sludge, wherein the filtrate is discharged into a phosphorus-containing wastewater regulating tank for continuous treatment;

(3 q) discharging the supernatant of the discharged water sedimentation tank into a discharged water intermediate tank, lifting the wastewater in the discharged water intermediate tank to a discharged water aeration biological denitrification filter, then feeding the discharged water into the discharged water aeration biological denitrification filter, and then feeding the discharged water of the discharged water aeration biological denitrification filter into a discharged water tank;

(3 r) adding NaOH or H ₂SO₄ into a water discharge pool, aerating and stirring, adjusting the pH value to 6-9, and discharging the effluent after reaching the standard;

(4) The method for treating the phosphorus-containing wastewater comprises the following steps:

(4a) The phosphorus-containing wastewater is singly collected and then discharged into a phosphorus-containing wastewater regulating tank to regulate the water quality and the water quantity, and then the wastewater in the phosphorus-containing wastewater regulating tank is pumped into a fourth pH regulating tank in an air floatation device;

(4b) Adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and discharging effluent into a fourth dephosphorizing reaction tank in the air floatation device;

(4c) Adding 80-100 mg/L of dephosphorizing agent FeSO ₄ into a fourth dephosphorizing reaction tank, stirring and reacting, and then discharging the wastewater into a fourth slow mixing tank in an air floatation device;

(4d) Adding a polymeric flocculant PAM into the fourth slow mixing tank, stirring to perform flocculation reaction, forming large-block flocs by particles in water, discharging the wastewater into an air floatation tank in an air floatation device, forming scum by the flocs, scraping the scum into a scum tank, discharging mud into a comprehensive mud concentration tank by gravity, filtering the mud in the comprehensive mud concentration tank by a second chamber filter press, transporting dry mud outwards, continuously treating the filtrate, and continuously performing dephosphorization reaction by the discharged water of the air floatation tank into a fourth pH value adjustment tank;

(4e) Adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and discharging effluent into a fourth dephosphorization reaction tank;

(4f) Adding 80-100 mg/L of phosphorus removal agent FeSO ₄ into a fourth phosphorus removal reaction tank, stirring and reacting, and then discharging wastewater into a fourth slow mixing tank;

(4g) Adding a polymeric flocculant PAM into the fourth slow mixing tank, mechanically stirring, performing flocculation reaction, forming large-block flocs by particles in water, discharging wastewater into a fourth primary sedimentation tank for gravity sedimentation, periodically discharging the precipitated sludge into a sludge bucket, performing filter pressing on the sludge in the sludge concentration tank by a second box filter press, performing outward transportation on dry sludge, discharging filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment, and discharging supernatant of the fourth primary sedimentation tank into a fourth pH regulating tank for continuous dephosphorization reaction;

(4h) Adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH to 9-10, and discharging the wastewater into a fourth quick mixing tank;

(4i) Adding coagulant polyaluminium chloride PAC into the fourth rapid mixing tank, aerating and stirring, coagulating the precipitated precipitate into larger particles, and then discharging the wastewater into a fourth slow mixing tank;

(4j) Adding a polymeric flocculant PAM into the fourth slow mixing tank, stirring, forming large-block flocs by particles in water, and then discharging the wastewater into a secondary sedimentation tank;

(4k) The flocs are subjected to gravity precipitation in a secondary sedimentation tank, the precipitated sludge enters a sludge bucket, the sludge is periodically discharged into a comprehensive sludge concentration tank, the sludge in the comprehensive sludge concentration tank is subjected to filter pressing through a second box type filter press, dry sludge is transported outwards, filtrate is discharged into a phosphorus-containing wastewater regulating tank for continuous treatment, supernatant fluid of the secondary sedimentation tank is discharged into a fourth intermediate tank for transfer, and then wastewater of the fourth intermediate tank is pumped into a third pH callback tank of a dyeing wastewater treatment system for continuous treatment.

2. The method according to claim 1, wherein in the steps (1 b) and (1 f) of the method for treating nickel-containing wastewater, the step (2 b) of the method for treating inorganic wastewater, the steps (3 e) and (3 o) of the method for treating dyeing wastewater, and the step (4 i) of the method for treating phosphorus-containing wastewater, the addition amount of the coagulant polyaluminum chloride PAC is 500-800 mg/L each time, and the stirring and mixing reaction time is 30 minutes.

3. The method according to claim 1, wherein in the steps (1 c) and (1G) of the nickel-containing wastewater treatment method, the step (2 c) of the inorganic wastewater treatment method, the steps (3 f) and (3 p) of the dyeing wastewater treatment method, and the steps (4 d), (4G) and (4 j) of the phosphorus-containing wastewater treatment method, the addition amount of the polymeric flocculant PAM is 5 to 8mg/L each time, the stirring and mixing reaction time is 30 minutes, and the average speed gradient G value is controlled to be 30 to 60s ^-1.

4. The method for treating anodized waste water according to claim 1 wherein the amount of H ₂O₂ added in the Fenton reaction tank is 100-200 mg/L, the amount of FeSO ₄ added is 200-300 mg/L, and the stirring and mixing reaction time is 1H.

5. The method for treating anodized wastewater according to claim 1, characterized in that the mixed solution in the aerobic tank is refluxed to the anoxic tank at a reflux ratio of 100 to 400%.

6. The method for treating anodized wastewater according to claim 1, characterized in that the scale inhibitor added in the third pipe mixer is LTLD-RO scale inhibitor, and the addition amount is 3-5 ppm.

7. An anodic oxidation wastewater treatment system for implementing the method of claim 1, comprising an associated nickel-containing wastewater treatment system, inorganic wastewater treatment system, dyeing wastewater treatment system, discharge water system, phosphorus-containing wastewater treatment system,

The system comprises a discharge water pH adjusting tank, a discharge water Fenton reaction tank, a discharge water pH callback tank, a discharge water reduction reaction tank, a discharge water quick mixing tank, a discharge water slow mixing tank, a discharge water sedimentation tank, a comprehensive sludge concentration tank, a discharge water intermediate tank, a discharge water biological aerated denitrification tank and a discharge water tank, wherein the outlet of the discharge water pH adjusting tank is connected to the discharge water Fenton reaction tank, the outlet of the discharge water Fenton reaction tank is connected to the discharge water pH callback tank, the outlet of the discharge water pH callback tank is connected to the discharge water reduction reaction tank, the outlet of the discharge water reduction reaction tank is connected to the discharge water quick mixing tank, the outlet of the discharge water quick mixing tank is connected to the discharge water slow mixing tank, the outlet of the discharge water slow mixing tank is connected to the discharge water sedimentation tank, the outlet of the discharge water sedimentation tank is connected to the comprehensive sludge concentration tank, the other outlet of the discharge water sedimentation tank is connected to the discharge water intermediate tank, the outlet of the discharge water intermediate tank is connected to the discharge biological aerated denitrification tank, the outlet of the discharge water biological aerated denitrification tank is connected to the discharge water biological aerated denitrification tank, and the discharge water biological aerated denitrification tank is connected to the discharge water outlet of the discharge water biological aerated denitrification tank;

8. The anodizing wastewater treatment system according to claim 7, wherein the first one-to-one pH adjusting tank, the first two-pH adjusting tank, the middle clean water tank, the second one-to-one pH adjusting tank, the first pipeline mixer, the third one-to-one pH adjusting tank, the discharged water pH adjusting tank, the fourth one-to-one pH adjusting tank, the fourth two-to-one pH adjusting tank and the fourth three-pH adjusting tank are all provided with pH on-line control devices.

9. The anodizing wastewater treatment system according to claim 7, wherein the second pipeline mixer, the third reduction reaction tank, the discharged water callback tank and the discharged water reduction reaction tank are all provided with ORP on-line control devices.