CN111453920A

CN111453920A - Anodic oxidation wastewater treatment method and system

Info

Publication number: CN111453920A
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: 2020-07-28

Abstract

The invention provides an anodic oxidation wastewater treatment method and system, wherein the anodic oxidation wastewater comprises nickel-containing wastewater, inorganic wastewater, dyeing wastewater and phosphorus-containing wastewater. After the treatment by the method and the system, the anodic oxidation waste water on the production line can be fully and circularly purified, and the purified produced water can be discharged or recycled after reaching the standard. The invention solves the treatment problem of the traditional anodic oxidation wastewater treatment process and saves the treatment cost.

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

The nickel-containing wastewater contains a pollutant nickel strictly controlled by the state, the dyeing wastewater contains high-concentration chromaticity, and the phosphorus-containing wastewater contains high-concentration phosphorus and oil stain, which are main treatment difficulties of anodic oxidation wastewater. Along with the stricter and stricter discharge standard, the treatment difficulty of the anodic oxidation wastewater is increased, and the conventional method and system for treating the anodic oxidation wastewater are difficult to comprehensively treat various kinds of wastewater in the anodic oxidation wastewater and have higher treatment cost. Phosphorus-containing wastewater is generally dephosphorized by a dosing precipitation method at present, and commonly used dephosphorizing agents for the phosphorus-containing wastewater comprise iron salt, calcium salt and aluminum salt, and the subsequent membrane treatment is influenced because the calcium salt is easy to scale. Therefore, the invention provides an anodic oxidation wastewater treatment method and system which can save cost and reduce the addition of a flocculating agent.

Disclosure of Invention

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

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

an anodic oxidation wastewater treatment method comprises the following steps:

the nickel-containing wastewater treatment method comprises the following steps:

step 1a, discharging nickel-containing wastewater into a nickel-containing wastewater adjusting tank to adjust the water quality and water quantity, pumping into a first pH adjusting tank, adding NaOH, aerating and stirring, adjusting the pH value to 9-11, and separating out nickel hydroxide precipitate formed by nickel ions and hydroxyl ions in the wastewater;

step 1b, discharging the wastewater into a first rapid mixing tank, adding a coagulant polyaluminium chloride (PAC), aerating and stirring, and coagulating the precipitated precipitate into larger particles;

step 1c, then discharging the wastewater into a first slow mixing tank, adding a polymeric flocculant PAM (polyacrylamide) and stirring, wherein the particulate matters in the water form large flocs;

step 1d, discharging the sewage in the first one-to-one slow mixing tank into a first one-to-one primary settling tank for gravity settling, and discharging the settled sludge into a sludge hopper and a nickel-containing sludge concentration tank periodically;

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

step 1f, discharging the wastewater into a first and second quick mixing tank, adding a coagulant polyaluminium chloride (PAC), aerating and stirring, and coagulating the precipitated precipitate into larger particles;

step 1g, discharging the wastewater in the first and second fast mixing tanks into the first and second slow mixing tanks, adding a polymeric flocculant PAM (polyacrylamide), and stirring, wherein under the action of adsorption and net capture, large flocs are formed by particles in the water;

step 1h, discharging the wastewater in the first and second slow mixing tanks into a first inclined tube sedimentation tank for gravity sedimentation, allowing the precipitated sludge to enter a mud bucket and periodically discharge into a nickel-containing sludge concentration tank, performing pressure filtration on the sludge in the nickel-containing sludge concentration tank by using a first box filter press, transporting dry sludge outwards, and discharging the filtrate into a nickel-containing wastewater adjusting tank for secondary treatment;

step 1i, discharging the supernatant of the first 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, carrying out aeration stirring, pumping the wastewater into a first quartz sand filter for treatment, and directly discharging the effluent of the first quartz sand filter into an inorganic clean water tank in an inorganic wastewater treatment system if the nickel ion content is detected to be low; if the content of nickel ions is detected to be higher, the nickel ions are treated by an ion exchanger, and the effluent is discharged into an inorganic clear water tank in an inorganic wastewater treatment system;

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

step 2a, independently collecting inorganic wastewater, discharging the inorganic wastewater into an inorganic wastewater adjusting tank to adjust the water quality and water quantity, pumping the wastewater into a second pH adjusting tank, adding NaOH, aerating and stirring, adjusting the pH value to 8.5-9, and separating out aluminum hydroxide precipitate formed by aluminum ions and hydroxyl ions in the wastewater;

step 2b, discharging the wastewater into a second quick mixing tank, adding a coagulant polyaluminium chloride (PAC), aerating and stirring, and coagulating the precipitated precipitate into larger particles;

step 2c, discharging the wastewater into a second slow mixing tank, adding a polymeric flocculant PAM (polyacrylamide) and stirring, wherein large flocs are formed 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, allowing the precipitated sludge to enter a mud bucket and periodically discharge into a comprehensive sludge concentration tank, performing pressure filtration on the sludge in the comprehensive sludge concentration tank by using a second box-type pressure filter, transporting the dry sludge outwards, and discharging the filtrate into a phosphorus-containing wastewater regulating tank for treatment;

step 2e, discharging the supernatant 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 for treatment, then 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 into a water inlet pipeline of the UF membrane system through a first pipeline mixer to adjust the pH value, adding a reducing agent sodium bisulfite through a second pipeline mixer to adjust the oxidation-reduction potential, and 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 water body is treated by the UF membrane system, so that the oxidation-reduction potential is controlled to be +/-150 mv; after the wastewater is treated by a UF membrane system, discharging the effluent of the UF membrane system into a UF product water tank;

step 2f, discharging the effluent of the UF water production pool into a primary RO system, discharging the produced water of the primary RO system into a primary RO water production tank, and discharging the concentrated water generated by the primary RO system into a dyeing wastewater adjusting pool for treatment; one part of water in the primary RO water production tank is recycled as tap water, and the other part of the water is discharged into a secondary RO system;

step 3, the treatment method of the dyeing wastewater comprises the following steps:

step 3a, independently collecting dyeing wastewater, then feeding the dyeing wastewater into a dyeing wastewater adjusting tank to adjust the water quality and water quantity, then pumping the dyeing wastewater into a third pH adjusting tank, adding sulfuric acid to adjust the pH value to 3-4, carrying out aeration stirring, and discharging effluent into a Fenton reaction tank;

step 3b, respectively adding H2O2 and FeSO4 into the Fenton reaction tank to perform Fenton reaction, aerating and stirring, and discharging effluent after the Fenton reaction into a third pH readjustment tank;

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

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

step 3e, adding a coagulant polyaluminium chloride PAC into the third fast mixing tank, aerating and stirring to coagulate 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, wherein the particles in the water form large flocs;

step 3g, discharging the sewage in the third slow mixing tank into a third inclined tube sedimentation tank for gravity sedimentation, allowing the precipitated sludge to enter a mud bucket and be periodically discharged into a comprehensive sludge concentration tank, performing pressure filtration on the sludge in the concentration tank by using a second box type pressure filter, transporting the dry sludge outwards, and discharging the filtrate into a phosphorus-containing wastewater adjusting tank for continuous treatment;

discharging the supernatant of the third inclined tube sedimentation tank into a third intermediate tank, adding sulfuric acid, aerating, 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 the wastewater in the anaerobic tank, then discharging anaerobic effluent into the anoxic tank for carrying out denitrification reaction and stirring, then discharging the effluent into the aerobic tank for carrying out oxidation and nitrification reaction, and pumping the mixed liquor in the aerobic tank back to the anoxic tank for continuing denitrification reaction;

step 3j, discharging the effluent of the aerobic tank into an MBR (membrane bioreactor), filtering the wastewater by using an ultrafiltration membrane assembly, pumping the wastewater into an MBR water production tank, intercepting sludge in the MBR membrane tank, and pumping the intercepted sludge back to the anaerobic tank, the anoxic tank and the aerobic tank; part of water in the MBR water producing tank is discharged into a UF water producing tank of the inorganic wastewater treatment system for reuse water treatment, and the other part of water enters a discharge water pH adjusting tank of a discharge water system for continuous treatment;

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 a discharged water Fenton reaction tank;

step 3l, respectively adding H202 and FeSO4 into a discharged water Fenton reaction tank to carry out Fenton reaction and aeration stirring, and enabling effluent after the Fenton reaction to enter a discharged water pH readjustment tank;

step 3m, adding NaOH into the discharged water pH adjusting tank, aerating and stirring, adjusting the pH value to 7-8, and then feeding the discharged water into a discharged water reduction reaction tank;

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

step 3, adding a coagulant polyaluminium chloride PAC into the discharged water fast mixing tank, aerating and stirring to coagulate suspended matters in the sewage into larger particles, and then discharging the particles into the discharged water slow mixing tank;

step 3p, adding a polymeric flocculant PAM into the slow mixing tank of the discharged water, stirring, forming large flocs by particles in the water, then discharging the water into a settling tank of the discharged water for gravity settling, feeding the settled sludge into a mud bucket, 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 box filter press, then transporting the dry sludge out, and discharging the filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment;

step 3q, discharging the supernatant of the discharge water sedimentation tank into a discharge water intermediate tank, lifting the wastewater in the discharge water intermediate tank to a discharge water aeration biological denitrification filter, then discharging the effluent into the discharge water aeration biological denitrification filter, and then discharging the effluent of the discharge water aeration biological nitrification filter into a discharge water pool;

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

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

step 4a, separately collecting the phosphorus-containing wastewater, discharging the phosphorus-containing wastewater into a phosphorus-containing wastewater adjusting tank to adjust the water quality and water quantity, and pumping the wastewater in the phosphorus-containing wastewater adjusting tank into a fourth pH adjusting tank in the air floatation device;

step 4b, adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and discharging the discharged water into a fourth phosphorus removal reaction tank in the air flotation device;

step 4c, adding a phosphorus removing agent into the fourth phosphorus removing reaction tank, stirring and reacting, and then discharging the wastewater into a fourth slow mixing tank in the air flotation 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 flotation tank in an air flotation device, discharging the scum into a scum tank, discharging the scum into a comprehensive sludge concentration tank through gravity, performing pressure filtration on the sludge in the comprehensive sludge concentration tank through a second chamber type pressure filter, transporting the dry sludge outwards, flowing the filtrate into a phosphorus-containing wastewater adjusting tank for continuous treatment, and feeding the discharged water of the air flotation tank into a fourth second pH adjusting tank for continuous dephosphorization reaction;

step 4e, adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and then discharging effluent into the fourth phosphorus removal reaction tank;

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

step 4g, adding a polymeric flocculant PAM into a fourth slow mixing tank, mechanically stirring, performing flocculation reaction, forming large flocs by particles in water, then discharging wastewater into a fourth primary settling tank for gravity settling, feeding settled sludge into a sludge hopper, periodically discharging 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 adjusting tank for continuous treatment, and discharging supernatant of the fourth primary settling tank into a fourth third pH adjusting 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 a coagulant polyaluminium chloride PAC into the fourth fast mixing tank, aerating and stirring, coagulating the precipitated precipitate into larger particles, and then discharging the wastewater into a fourth third slow mixing tank;

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

and 4k, performing gravity precipitation on the flocs in a secondary sedimentation tank, allowing the precipitated sludge to enter a sludge hopper, periodically discharging the sludge into a comprehensive sludge concentration tank, performing pressure filtration on the sludge in the comprehensive sludge concentration tank by using a second chamber type pressure filter, transporting dry sludge outwards, discharging filtrate into a phosphorus-containing wastewater adjusting tank for continuous treatment, discharging supernatant of the secondary sedimentation tank into a fourth intermediate tank for transfer, and pumping wastewater of the fourth intermediate tank into a third pH adjusting-back tank of the 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 addition amount of a coagulant polyaluminium chloride PAC is 500-800 mg/L each time, and the reaction time of stirring and mixing is 30 min.

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

Further, in order to ensure the effect of the Fenton reaction, the amount of H202 added to the Fenton reaction tank is 100-200 mg/L4 and 200-300 mg/L, and the reaction time is 1 hour by stirring and mixing.

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

Further, in order to ensure the effect of phosphorus removal reaction and reduce the cost, the phosphorus removal agents added into the fourth phosphorus removal reaction tank and the fourth phosphorus removal reaction tank are FeSO4, and the addition amount is 80-100 mg/L.

Furthermore, in order to effectively prevent the formation of scale and microorganism adhesion bodies and improve the salt rejection rate and the water yield of the system, the scale inhibitor added into the third pipeline mixer is L T L D-RO scale inhibitor, and the addition amount 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 associated with each other;

the nickel-containing wastewater treatment system comprises a nickel-containing wastewater adjusting tank, a first pH adjusting tank, a first fast mixing tank, a first slow mixing tank, a first primary settling tank, a nickel-containing sludge concentrating tank, a first chamber type filter press, a first second pH adjusting tank, a first second fast mixing tank, a first second slow mixing tank, a first inclined tube sedimentation tank, a middle clear water tank, a first quartz sand filter and an ion exchanger, wherein an outlet of the nickel-containing wastewater adjusting tank is connected to the first pH adjusting tank; one outlet of the first primary sedimentation tank is connected to a nickel-containing sludge concentration tank, the outlet of the nickel-containing sludge concentration tank is connected to a first chamber filter press by a pump, and the other outlet of the first primary sedimentation tank is connected to a first secondary pH adjusting tank; an outlet of the first and second pH adjusting pool is connected to a first and second fast mixing pool, an outlet of the first and second fast mixing pool is connected to a first and second slow mixing pool, and an outlet of the first and second slow mixing pool is connected to a first inclined tube sedimentation pool; one outlet of the first inclined tube sedimentation tank is connected to the nickel-containing sludge concentration tank, and the other outlet of the first inclined tube sedimentation tank is connected to the middle clean water tank; the outlet of the middle clean water tank is connected to the first quartz sand filter; one outlet of the first quartz sand filter is connected to an inorganic clean water tank in the inorganic wastewater treatment system, and the other outlet of the first quartz sand filter is connected with the ion exchanger; the outlet of the ion exchanger is connected to an inorganic clean water tank of an inorganic wastewater treatment system;

the inorganic wastewater treatment system comprises an inorganic wastewater adjusting tank, a second pH adjusting tank, a second first fast mixing tank, a second slow mixing tank, a second primary settling tank, a comprehensive sludge concentration tank, an inorganic clear water tank and a reuse water system, wherein the reuse water system comprises an ion exchanger, a second 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 production water tank, a primary RO system, a primary RO production water tank, a secondary RO system and a pure water production water tank, an outlet of the inorganic wastewater adjusting tank is connected to the second pH adjusting tank, an outlet of the second pH adjusting tank is connected to the second fast mixing tank, an outlet of the second fast mixing tank is connected to the second primary slow mixing tank, and an outlet of the second slow mixing tank is connected to the second primary settling tank; one 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 one inlet of an inorganic clean water tank, and the other inlet of the inorganic clean water tank is connected to an ion exchanger in the nickel-containing wastewater system; the outlet of the inorganic clean water tank is connected to a second quartz sand filter, the outlet of the second quartz sand filter is connected to an active carbon filter, the outlet of the active carbon filter is connected to an UF membrane system through a pipeline, and a first pipeline mixer, a second pipeline mixer and a third pipeline mixer are sequentially arranged on the pipeline; the outlet of the UF membrane system is connected to an inlet of an UF water producing tank, and the other inlet of the UF water producing tank is connected to an outlet of an MBR water producing tank of the dyeing wastewater treatment system; the outlet of the UF water producing pond is connected to a primary RO system; one outlet of the primary RO system is connected to a dyeing wastewater adjusting tank of the dyeing wastewater treatment system, and the other outlet of the primary RO system is connected to the secondary RO system; one outlet of the second-level RO system is connected to the first-level RO system by a pump, and the other outlet is connected to a pure aquatic product water tank;

the dyeing wastewater treatment system comprises a dyeing wastewater adjusting tank, a third pH adjusting tank, a Fenton reaction tank, a third pH adjusting-back tank, a fourth intermediate tank, a third reduction reaction tank, a third fast 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, an outlet of the dyeing wastewater adjusting tank is connected to the third pH adjusting tank, an outlet of the third pH adjusting tank is connected to the Fenton reaction tank, an outlet of the Fenton reaction tank is connected to an inlet of the third pH adjusting-back tank, another inlet of the third pH adjusting-back tank is connected to an outlet of the fourth intermediate tank of the phosphorus-containing wastewater treatment system, an outlet of the third pH adjusting-back tank is connected to the reduction reaction tank, the outlet of the reduction reaction tank is connected to a third fast mixing tank, the outlet of the third fast mixing tank is connected to a third slow mixing tank, and the outlet of the third slow mixing tank is connected to a third inclined tube sedimentation tank; one outlet of the third inclined tube sedimentation tank is connected to the comprehensive sludge concentration tank, and the other outlet of the third inclined tube sedimentation tank is connected to a third intermediate tank; the outlet of the third middle tank is connected to an anaerobic tank of a biochemical system, the outlet of the anaerobic tank is connected to an anoxic tank, the outlet of the anoxic tank is connected to an aerobic tank, one outlet of the aerobic tank is connected to the anoxic tank by a pump, and the other outlet of the aerobic tank is connected to an MBR membrane tank; an immersed ultrafiltration membrane component is arranged in the MBR membrane tank; one outlet of the MBR membrane tank is respectively connected back to the anaerobic tank, the anoxic tank and the aerobic tank by a pump, and the other outlet of the MBR membrane tank is connected to an MBR water production tank; one outlet of the MBR water producing tank is connected to a UF water producing tank of the inorganic wastewater treatment system, and the other outlet of the MBR water producing tank is connected to a discharged water pH adjusting tank of a discharged water system;

the discharged water treatment system comprises a discharged water pH adjusting tank, a discharged water Fenton reaction tank, a discharged water pH adjusting tank, a discharged water reduction reaction tank, a discharged water fast mixing tank, a discharged water slow mixing tank, a discharged water sedimentation tank, an integrated sludge concentration tank, a discharged water intermediate tank, a discharged water aeration biological denitrification filter, a discharged water aeration biological nitrification filter and a discharged water tank, wherein an outlet of the discharged water pH adjusting tank is connected to the discharged water Fenton reaction tank; one outlet of the discharged water sedimentation tank is connected to the comprehensive sludge concentration tank, and the other outlet of the discharged water sedimentation tank is connected to the discharged water intermediate tank; the outlet of the discharge water intermediate tank is connected to a discharge water aeration biological denitrification filter, the outlet of the discharge water aeration biological denitrification filter is connected to a discharge water aeration biological nitrification filter, and the outlet of the discharge water aeration biological nitrification filter is connected to a discharge water pool;

the phosphorus-containing wastewater treatment system comprises a phosphorus-containing wastewater adjusting tank, an air floatation device, a scum tank, a comprehensive sludge concentration tank, a fourth second pH adjusting tank, a fourth second phosphorus removal reaction tank, a fourth second slow mixing tank, a fourth primary sedimentation tank, a fourth third pH adjusting tank, a fourth fast mixing tank, a fourth third slow mixing tank, a secondary sedimentation tank and a fourth intermediate tank, wherein the air floatation device comprises a fourth pH adjusting tank, a fourth phosphorus removal reaction tank, a fourth slow mixing tank and an air floatation tank, an outlet of the phosphorus-containing wastewater adjusting tank is connected to the fourth pH adjusting tank of the air floatation device, an outlet of the fourth pH adjusting tank is connected to the fourth phosphorus removal reaction tank, an outlet of the fourth phosphorus removal reaction tank is connected to the air floatation tank, and an outlet of the air floatation tank is connected to the scum tank; one outlet of the scum pond is connected to the comprehensive sludge concentration pond, the other outlet of the scum pond is connected to a fourth pH adjusting pond, an outlet of the fourth pH adjusting pond is connected to a fourth phosphorus removal reaction pond, an outlet of the fourth phosphorus removal reaction pond is connected to a fourth second slow mixing pond, and an outlet of the fourth second slow mixing pond is connected to a fourth primary sedimentation pond; one outlet of the fourth primary sedimentation tank is connected to the comprehensive sludge concentration tank, and the other outlet of the fourth primary sedimentation tank is connected to the fourth pH adjusting tank; an outlet of the fourth third pH adjusting tank is connected to a fourth first fast mixing tank, an outlet of the fourth first fast mixing tank is connected to a fourth third slow mixing tank, and an outlet of the fourth third slow mixing tank is connected to a secondary sedimentation tank; one outlet of the secondary sedimentation tank is connected to the comprehensive sludge concentration tank, and the other outlet of the secondary sedimentation tank is connected to the fourth intermediate tank; the outlet of the fourth intermediate tank is connected to a third pH callback tank of the dyeing wastewater treatment system;

the outlet of the comprehensive sludge concentration tank connected with the inorganic wastewater treatment system, the dyeing wastewater treatment system, the water discharge 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 adjusting tank.

Furthermore, in order to control the pH value and the pH precision and ensure the acid-base neutralization effect, pH online control devices are arranged in the first pH adjusting tank, the first and second pH adjusting tanks, the intermediate clear water tank, the second pH adjusting tank, the first pipeline mixer, the third pH adjusting tank, the discharge water pH adjusting tank, the fourth pH adjusting tank and the fourth pH adjusting tank.

Further, in order to facilitate automatic control and detection of the oxidation-reduction potential value in the wastewater, ORP online control devices are arranged in the second pipeline mixer, the third reduction reaction tank, the discharged water callback tank and the discharged water reduction reaction tank.

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

Drawings

FIG. 1 is a schematic view of the overall flow of an anodizing wastewater treatment system of the present invention.

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

FIG. 3 is a schematic flow diagram of an inorganic wastewater treatment system according to the present invention.

FIG. 4 is a schematic view showing a flow of the dyeing wastewater treatment system of the present invention.

FIG. 5 is a schematic flow diagram of the effluent treatment system of the present invention.

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

Detailed Description

Fig. 1 shows a method and a system for treating anodic oxidation wastewater, which specifically comprises the following steps:

the wastewater generated by the anodic oxidation production line is mainly divided into four types, namely nickel-containing wastewater, inorganic wastewater, dyeing wastewater, phosphorus-containing wastewater and the like, and the four types of wastewater need to be treated respectively and discharged and recycled in a unified manner.

The nickel-containing wastewater is mainly derived 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 figure 2, the treatment method of nickel-containing wastewater comprises the following steps:

step 1a, after nickel-containing wastewater discharged from a workshop is collected independently, discharging the wastewater into a nickel-containing wastewater adjusting tank to adjust the water quality and water quantity, pumping the wastewater into a first pH adjusting tank by using a lift pump, adding NaOH to adjust the pH value to 9-11 in order to ensure the optimal pH of a flocculation reaction, automatically controlling the adding amount of the NaOH by using a pH online control device arranged in the first pH adjusting tank, carrying out aeration stirring mixing reaction for 30 minutes, and separating out nickel hydroxide precipitate formed by nickel ions and hydroxyl ions in the wastewater;

step 1b, discharging the wastewater into a first rapid mixing tank, adding a coagulant polyaluminium chloride (PAC) and carrying out aeration stirring for 30 minutes, wherein the addition amount of the PAC is 500-800 mg/L, fully mixing and reacting for 30 minutes through aeration stirring, and coagulating the separated nickel hydroxide precipitate into larger particles;

step 1c, then discharging the wastewater into a first slow mixing tank, adding a polymeric flocculant PAM (polyacrylamide) and mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the average velocity gradient G value is controlled by the mixing and stirring strength to be 30-60 s-1, and under the adsorption and net-catching action of the PAM, the particles in the water form large floccules;

step 1d, discharging the sewage in the first one-to-one slow mixing tank into a first one-to-one primary settling tank for gravity settling, and discharging the settled sludge into a sludge hopper of the first one-to-one primary settling tank and a nickel-containing sludge concentration tank periodically;

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, aerating, stirring and reacting for 30 minutes, wherein the adding amount of the NaOH is automatically controlled by a pH online control device arranged in the first secondary pH adjustment tank, and nickel ions and hydroxyl ions in the wastewater form nickel hydroxide precipitates to be separated out;

step 1f, discharging the wastewater into a first primary and secondary quick mixing tank, adding a coagulant polyaluminium chloride (PAC) and carrying out aeration stirring for 30 minutes, wherein the addition amount of the PAC is 500-800 mg/L, fully mixing and reacting for 30 minutes through aeration stirring, and coagulating the separated nickel hydroxide precipitate into larger particles;

step 1G, discharging the wastewater in the first and second fast mixing tanks into the first and second slow mixing tanks, adding a polymeric flocculant PAM (polyacrylamide) and mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the average velocity gradient G value is controlled by the mixing and stirring strength to be 30-60 s-1, and under the adsorption and net catching effects of the PAM, the particles in the water form large flocs;

step 1h, discharging the wastewater in the first and second slow mixing tanks into a first inclined tube sedimentation tank for gravity sedimentation, feeding the precipitated sludge into a mud bucket of the first inclined tube sedimentation tank, periodically discharging the sludge into a nickel-containing sludge concentration tank, carrying out pressure filtration on the sludge in the nickel-containing sludge concentration tank by using a first box-type pressure filter, transporting the dry sludge outwards, and discharging the filtrate into a nickel-containing wastewater regulating tank for secondary treatment;

and 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, automatically controlling the adding amount of the sulfuric acid by a pH online control device arranged in the middle clean water tank, and carrying out aeration stirring reaction for 30 minutes. Pumping the wastewater of the intermediate clean water tank into a first quartz sand filter by using a lift pump for treatment, and directly discharging the effluent of the first quartz sand filter into an inorganic clean water tank in an inorganic wastewater treatment system for continuous treatment if the nickel ion content of the effluent is detected to be low; if the content of nickel ions is detected to be higher, the nickel ions are treated by the ion exchanger, the discharged water is discharged into an inorganic clean water tank in the inorganic wastewater treatment system for continuous treatment, and the water in the inorganic clean water tank is pumped into a reuse water system by a lift pump for continuous treatment.

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

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

step 2a, independently collecting inorganic wastewater, discharging the inorganic wastewater into an inorganic wastewater adjusting tank to adjust water quality and water quantity, pumping the wastewater into a second pH adjusting tank by using a lifting pump, adding NaOH to adjust the pH value to 8.5-9 in order to ensure the optimal pH value of a flocculation reaction, automatically controlling the adding amount of the NaOH by using a pH online control device arranged in the second pH adjusting tank, carrying out aeration stirring reaction for 30 minutes, and separating out an aluminum hydroxide precipitate formed by aluminum ions and hydroxyl ions in the wastewater;

step 2b, discharging the wastewater in the second pH adjusting tank into a second quick mixing tank, adding a coagulant polyaluminium chloride (PAC), carrying out aeration stirring reaction for 30 minutes, wherein the adding amount of the PAC is 500-800 mg/L, and coagulating the precipitated precipitate into larger particles;

step 2c, discharging the wastewater into a second slow mixing tank, adding a polymeric flocculant PAM (polyacrylamide) and mechanically stirring for 30 minutes, wherein the addition amount of the PAM is 5-8 mg/L, the average velocity gradient G value is controlled by the mixing and stirring strength to be 30-60 s-1, and under the adsorption and net-catching effects of the PAM, the particles in the water form large floccules;

step 2d, discharging the sewage in the second slow mixing tank into a second primary settling tank for gravity settling, feeding the settled sludge into a mud bucket of the second primary settling tank, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out pressure filtration on the sludge in the concentration tank by a second box-type pressure filter, transporting the dry sludge outwards, and discharging the filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment;

step 2e, discharging the supernatant 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 using a lift pump for treatment, treating the wastewater by using an activated carbon filter, and discharging the wastewater filtered by the activated carbon filter into an UF membrane system for treatment, wherein in order to ensure the optimal pH of the membrane treatment, a first pipeline mixer for adding sulfuric acid and fully mixing with the wastewater, a second pipeline mixer for adding a reducing agent sodium bisulfite and fully mixing with the wastewater and a scale inhibitor are arranged on a water inlet pipeline of the UF membrane system, the scale inhibitor can use L T L D-RO scale inhibitor, the main components of the scale inhibitor are organic dispersion, organic complex, monatomic oxyhydrogen-based polymer and the like, the adding amount is 3-5 ppm, the scale inhibitor and the like and 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 before the UF membrane system treatment reaches 6.5-7.5, adjusting the reducing agent to control the oxidation-reduction potential to be 150mv, the adding amount of the ORP of the reducing agent into an online mixing device, and automatically controlling the UF membrane system by adding a second pipeline mixing device for controlling the amount of the wastewater after the ORP production device;

step 2f, discharging the effluent of the UF water production pool into a primary RO system, discharging the produced water of the primary RO system into a primary RO water production tank, and discharging the concentrated water generated by the primary RO system into a dyeing wastewater adjusting pool of a dyeing wastewater treatment system for continuous treatment; one part of water in the primary RO water production tank is recycled as tap water, and the other part of the water is discharged into a secondary RO system;

the dyeing wastewater is mainly derived from dyeing waste liquid and dyed cleaning wastewater, and the main pollutants of the dyeing wastewater are COD, chroma and SS.

As shown in fig. 4 and 5, the method for treating dyeing wastewater comprises:

and 3a, independently collecting the dyeing wastewater, then feeding the dyeing wastewater into a dyeing wastewater adjusting tank, wherein the dyeing wastewater adjusting tank is used for receiving the dyeing wastewater discharged from the production line and concentrated water generated by the first-stage RO, and pumping the wastewater into a third pH adjusting tank by using a lifting pump after the water quality and the water quantity are fully adjusted. In order to ensure the optimal pH value of the subsequent Fenton reaction, adding sulfuric acid into the 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 online control device arranged in the third pH adjusting tank, and discharging the discharged water into the Fenton reaction tank after the aeration stirring reaction is carried out for 30 minutes;

step 3b, respectively adding H2O2 and FeSO4 into the Fenton reaction tank to carry out Fenton reaction, wherein the addition of H202 is 100-200 mg/L4 and the addition of H202 is 200-300 mg/L, and discharging effluent after the Fenton reaction into a third pH callback tank after the aeration stirring reaction is carried out for 1 hour;

step 3c, adding NaOH into the third pH readjustment tank, adjusting the pH value to 7-8, automatically controlling the adding amount of the NaOH by using a pH online control device arranged in the third pH readjustment tank, and discharging effluent into the third reduction reaction tank after aeration stirring reaction for 30 minutes;

and 3d, performing reduction reaction on the redundant oxidant by using the third reduction reaction tank, and reducing the influence of the oxidant on the subsequent reaction. Adding a reducing agent NaHSO3 into the third reduction reaction tank, carrying out mechanical stirring reaction for 30min to control the oxidation-reduction potential to be +/-150 mv, controlling the average speed gradient G value to be 30-60 s < -1 > by the aid of an ORP (oxidation-reduction potential) online control device arranged in the third reduction reaction tank according to the adding amount of the reducing agent, and then enabling the discharged water to enter a third quick mixing tank;

step 3e, adding a coagulant polyaluminium chloride PAC (polyaluminium chloride) into the third fast mixing tank, wherein the adding amount of the PAC is 500-800 mg/L, carrying out 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 (polyacrylamide) into the third slow mixing tank, wherein the adding amount of the PAM is 5-8 mg/L, mechanically stirring for 30 minutes, controlling the average velocity gradient G value to be 30-60 s < -1 > by the mixing and stirring strength, and forming large flocs by the particles in the water under the adsorption and net-trapping effects of the particles;

step 3g, discharging the sewage in the third slow mixing tank into a third inclined tube sedimentation tank for gravity sedimentation, discharging the precipitated sludge into a mud bucket and periodically into a comprehensive sludge concentration tank, carrying out pressure filtration on the sludge in the concentration tank by a second box type pressure filter, transporting dry sludge outwards, and discharging the filtrate into a phosphorus-containing wastewater regulating tank of a phosphorus-containing wastewater treatment system for continuous treatment;

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 then discharging the effluent into an anaerobic tank in a biochemical system;

and 3i, adopting an AAO + MBR process, namely a hydrolytic acidification + anoxic + aerobic + MBR process, wherein the wastewater entering the biochemical system firstly enters an anaerobic tank for anaerobic reaction, and the anaerobic tank is internally provided with a submersible stirrer so as to prevent sludge from being deposited in the anaerobic tank. Anaerobic effluent is discharged into an anoxic tank for denitrification reaction, and a submersible stirrer is arranged in the anoxic tank, so that sludge can be prevented from being deposited at the bottom, and the denitrification efficiency can be improved. Then the effluent is discharged into an aerobic tank for oxidation and nitration reaction, and the mixed liquid in the aerobic tank is pumped back to the anoxic tank for denitrification reaction. In order to improve the treatment effect of the biochemical system, the mixed liquid 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, and staying 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. Filtering the wastewater by using an immersed ultrafiltration membrane assembly, pumping the wastewater into an MBR water production 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; part of water in the MBR water producing tank is discharged into a UF water producing tank of the inorganic wastewater treatment system for reuse water treatment, and the other part of water enters a discharge water pH adjusting tank of a discharge water system for continuous treatment;

step 3k, adding sulfuric acid into the discharged water pH adjusting tank, carrying out aeration 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 using a pH online control device arranged in the discharged water pH adjusting tank, and then discharging the discharged water into the discharged water Fenton reaction tank;

step 3l, respectively adding H202 and FeSO4 into a discharged water Fenton reaction tank to carry out Fenton reaction, carrying out aeration stirring reaction for 1 hour, wherein the addition of the H202 is 100-200 mg/L4 and the addition of the H202 is 200-300 mg/L, and discharging discharged water after the Fenton reaction into a discharged water pH readjustment tank;

step 3m, adding NaOH into the discharged water pH adjusting tank, carrying out aeration stirring reaction for 30 minutes, adjusting the pH value to 7-8, automatically controlling the adding amount of the NaOH by using a pH online control device arranged in the discharged water pH adjusting tank, and then discharging the discharged water into a discharged water reduction reaction tank;

step 3n, the discharged water reduction reaction tank is used for carrying out reduction reaction on redundant oxidant and reducing the influence of the oxidant on subsequent reaction, 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 dosing amount of the reducing agent is automatically controlled by an ORP online control device arranged in the discharged water reduction reaction tank, the average speed gradient G value is controlled by the mixing stirring intensity to be 30-60 s < -1 >, and then the discharged water is discharged into a discharged water rapid mixing tank;

step 3, adding a coagulant polyaluminium chloride PAC into the discharged water fast mixing tank, aerating and stirring for 30 minutes, wherein the adding amount of the PAC is 500-800 mg/L, coagulating suspended matters in the sewage into larger particles, and then discharging the sewage into the discharged water slow mixing tank;

step 3p, adding a polymeric flocculant PAM into the slow mixing tank of the discharged water, mechanically stirring for 30 minutes, wherein the adding amount of the PAM is 5-8 mg/L, the mixing and stirring strength controls the average velocity gradient G value to be 30-60 s < -1 >, particles in the water form large flocs, then discharging the water into the settling tank of the discharged water for gravity settling, feeding the settled sludge into a mud bucket of the settling tank of the discharged water, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out outward transportation on dry sludge after the sludge in the sludge concentration tank is subjected to pressure filtration by a second chamber type pressure filter, and discharging the filtrate into a phosphorus-containing wastewater adjusting 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 discharged water intermediate tank is mainly used for transferring wastewater, pumping the wastewater in the discharged water intermediate tank into a discharged water aeration biological denitrification filter tank (a discharged water BAF-DN tank) by using a lift pump, enabling the retention time to be 3 hours, enabling the discharged water to enter a discharged water aeration biological nitrification filter tank (a discharged water BAF-CN tank), enabling the retention time to be 3 hours, removing COD (chemical oxygen demand) and denitrifying, and enabling the discharged water of the discharged water aeration biological nitrification filter tank to enter a discharged water tank;

and 3r, adding NaOH or H2SO4 into the discharged water pool, carrying out aeration stirring reaction for 30 minutes, adjusting the pH value to 6-9, automatically controlling the adding amount of the NaOH or H2S04 by using a pH online control device arranged in the discharged water pool, and discharging the discharged water after reaching the standard.

The phosphorus-containing wastewater is mainly derived from the cleaning wastewater after chemical polishing, and the main pollutants of the phosphorus-containing wastewater comprise COD, phosphorus, SS and the like.

As shown in FIG. 6, the method for treating phosphorus-containing wastewater comprises the following steps:

step 4a, separately collecting the phosphorus-containing wastewater, discharging the phosphorus-containing wastewater into a phosphorus-containing wastewater adjusting tank to adjust the water quality and water quantity, and pumping the wastewater in the phosphorus-containing wastewater adjusting tank into a fourth pH adjusting tank in the air floatation device by using a lift pump; the air floatation device is provided with a fourth pH adjusting tank, a fourth phosphorus removal reaction tank, a fourth slow mixing tank and an air floatation tank.

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 online control device arranged in the fourth pH adjusting tank, and discharging discharged water into a fourth phosphorus removal reaction tank in the air floatation device;

step 4c, adding a phosphorus removing agent into the fourth phosphorus removing reaction tank, mixing and stirring for 30 minutes, in order to ensure the effect of phosphorus removing reaction and reduce the cost, adding the phosphorus removing agent FeSO4 into the fourth phosphorus removing reaction tank, wherein the addition amount of the phosphorus removing agent FeSO4 is 80-100 mg/L4, the phosphorus removing agent has the functions of coagulation and phosphorus removing, forming ferrous phosphate precipitate in the fourth phosphorus removing reaction tank after reaction, and then discharging the wastewater into a fourth slow mixing tank in an air flotation device;

step 4d, adding a polymeric flocculant PAM into a fourth slow mixing tank, mechanically stirring for 30 minutes, performing flocculation reaction, wherein the adding amount of the PAM is 5-8 mg/L, the mixing and stirring strength controls the average velocity gradient G value to be 30-60 s < -1 >, under the action of adsorption net capture of the PAM, particles in water form large flocs, then discharging the wastewater into an air flotation tank in an air flotation device, adopting dissolved air flotation for air flotation, introducing air into the water, generating fine bubbles, enabling the fine phosphorus-containing suspended matters in the water to adhere to the air bubbles, floating to the water surface along with the bubbles, forming floating slag, scraping the floating slag into a floating slag tank by using a slag scraper, discharging the sludge into a comprehensive sludge concentration tank through gravity, performing pressure filtration on the sludge in the comprehensive sludge concentration tank through a second chamber type pressure filter, transporting the dry sludge, allowing filtrate to flow into a phosphorus-containing wastewater adjusting tank for continuous treatment, and discharging the effluent of the air flotation tank into a fourth pH adjusting tank for continuous phosphorus removal reaction;

step 4e, in order to ensure the optimal pH value of the phosphorus removal reaction, adding NaOH into the fourth pH adjusting tank, carrying out aeration stirring for 30 minutes, adjusting the pH value to 9-10, automatically controlling the adding amount of the NaOH by using a pH online control device arranged in the fourth pH adjusting tank, and then discharging the discharged water into the fourth phosphorus removal reaction tank;

step 4f, adding a phosphorus removal agent into the fourth second phosphorus removal reaction tank, wherein in order to ensure the effect of phosphorus removal reaction and reduce the cost, the phosphorus removal agent added into the fourth phosphorus removal reaction tank is FeSO4, the addition amount of the phosphorus removal agent is 80-100 mg/L4, the phosphorus removal agent has the functions of coagulation and phosphorus removal, ferrous phosphate is formed in the fourth second phosphorus removal reaction tank after reaction and precipitated, and then the wastewater is discharged into a fourth second slow mixing tank;

step 4G, adding a polymeric flocculant PAM into a fourth slow mixing tank, mechanically stirring for 30 minutes to perform flocculation reaction, wherein the adding amount of the PAM is 5-8 mg/L, the mixing and stirring strength controls the average velocity gradient G value to be 30-60 s < -1 >, particles in water form large flocs, then discharging the wastewater into a fourth primary settling tank for gravity precipitation, feeding the precipitated sludge into a mud bucket of the fourth primary settling tank, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out external transportation on dry sludge after the sludge in the sludge concentration tank is subjected to pressure filtration by a second chamber filter press, discharging the filtrate into a phosphorus-containing wastewater adjusting tank of a phosphorus-containing wastewater treatment system for continuous treatment, and discharging the supernatant of the fourth primary settling tank into a fourth pH adjusting tank for continuous phosphorus removal reaction;

step 4h, in order to ensure the optimal pH value of the flocculation reaction, adding NaOH into a fourth pH adjusting tank, carrying out aeration stirring reaction for 30 minutes, adjusting the pH to 9-10, automatically controlling the adding amount of the NaOH by a pH online control device arranged in the fourth pH adjusting tank, and then discharging the wastewater into a fourth fast mixing tank;

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

step 4j, adding a polymeric flocculant PAM into a fourth third slow mixing tank, mechanically stirring and reacting for 30 minutes, wherein the adding amount of the PAM is 5-8 mg/L, the average velocity gradient G value is controlled by the mixing and stirring strength to be 30-60 s < -1 >, particles in water form large flocs, and then discharging the wastewater into a second settling tank;

and 4k, performing gravity precipitation on the flocs in a secondary sedimentation tank, allowing the precipitated sludge to enter a sludge hopper of the secondary sedimentation tank, periodically discharging the sludge into a comprehensive sludge concentration tank, performing pressure filtration on the sludge in the comprehensive sludge concentration tank by using a second chamber filter press, transporting dry sludge, discharging filtrate into a phosphorus-containing wastewater adjusting tank for continuous treatment, allowing supernatant of the secondary sedimentation tank to enter a fourth intermediate tank for transfer, allowing the supernatant to stay for 1h, and pumping the wastewater in the fourth intermediate tank into a third pH adjusting-back tank of the dyeing wastewater treatment system by using a lift pump for treatment.

After the treatment of the nickel-containing wastewater treatment system, the inorganic wastewater treatment system, the dyeing wastewater treatment system, the water discharge system and the phosphorus-containing wastewater treatment system which are mutually associated, the anodic oxidation wastewater on the production line can be sufficiently and circularly purified, and the purified produced water can be discharged or recycled after reaching the standard.

The method and system for treating waste water by anodic oxidation according to the present invention are described above with reference to the accompanying drawings, and it is obvious that the present invention is not limited to the above-mentioned embodiments, and it falls within the scope of the present invention if various modifications are made by the method concept and technical solution of the present invention, or if the method is directly applied to other fields without modification.

Claims

1. An anodic oxidation wastewater treatment method is characterized by comprising the following steps of:

(1) the nickel-containing wastewater treatment method comprises the following steps:

(1a) discharging the nickel-containing wastewater into a nickel-containing wastewater adjusting tank to adjust the water quality and water quantity, pumping into a first pH adjusting tank, adding NaOH, aerating and stirring, adjusting the pH value to 9-11, and separating out 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), aerating and stirring, and coagulating the precipitated precipitate into larger particles;

(1c) then discharging the wastewater into a first slow mixing tank, adding a polymeric flocculant PAM (polyacrylamide) and stirring, wherein the particulate matters in the water form large flocs;

(1d) discharging the sewage in the first one-to-one slow mixing tank into a first one-to-one primary settling tank for gravity settling, and discharging the settled sludge into a sludge hopper and a nickel-containing sludge concentration tank periodically;

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

(1f) discharging the wastewater into a first and second quick mixing tank, adding a coagulant polyaluminium chloride (PAC), aerating and stirring, and coagulating the precipitated precipitate into larger particles;

(1g) discharging the wastewater in the first and second fast mixing tanks into the first and second slow mixing tanks, adding a polymeric flocculant PAM (polyacrylamide), and stirring, wherein under the action of adsorption and net-capturing, the particulate matters in the water form large flocs;

(1h) discharging the wastewater in the first and second slow mixing tanks into a first inclined tube sedimentation tank for gravity sedimentation, allowing the precipitated sludge to enter a sludge hopper and periodically discharge into a nickel-containing sludge concentration tank, performing pressure filtration on the sludge in the nickel-containing sludge concentration tank by using a first box type pressure filter, transporting the dry sludge outwards, and discharging the filtrate into a nickel-containing wastewater adjusting tank for secondary treatment;

(1i) discharging the supernatant of the first 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 the wastewater into a first quartz sand filter for treatment, and directly discharging the effluent of the first 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; if the content of nickel ions is detected to be higher, the nickel ions are treated by an ion exchanger, and the effluent is discharged into an inorganic clear water tank in an inorganic wastewater treatment system;

(2) the inorganic wastewater treatment method comprises the following steps:

(2a) independently collecting inorganic wastewater, discharging the inorganic wastewater into an inorganic wastewater adjusting tank to adjust the water quality and water quantity, pumping the wastewater into a second pH adjusting tank, adding NaOH, aerating and stirring, adjusting the pH value to 8.5-9, and separating out aluminum hydroxide precipitate formed by aluminum ions and hydroxyl ions in the wastewater;

(2b) discharging the wastewater into a second quick mixing tank, adding a coagulant polyaluminium chloride (PAC), aerating and stirring, and coagulating the precipitated precipitate into larger particles;

(2c) then discharging the wastewater into a second slow mixing tank, adding a polymeric flocculant PAM (polyacrylamide) and stirring, wherein large blocks of flocs are formed by particles in the water;

(2d) discharging the sewage in the second slow mixing tank into a second primary settling tank for gravity settling, allowing the settled sludge to enter a sludge hopper and periodically discharge into a comprehensive sludge concentration tank, performing pressure filtration on the sludge in the comprehensive sludge concentration tank by using a second box-type pressure filter, transporting dry sludge outwards, and discharging the filtrate into a phosphorus-containing wastewater adjusting tank for treatment;

(2e) discharging the supernatant 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 for treatment, treating the wastewater by an activated carbon filter, and discharging the filtered wastewater into an UF membrane system for treatment by a pipeline; adding sulfuric acid into a water inlet pipeline of the UF membrane system through a first pipeline mixer to adjust the pH value, adding a reducing agent sodium bisulfite through a second pipeline mixer to adjust the oxidation-reduction potential, and 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 water body is treated by the UF membrane system, so that the oxidation-reduction potential is controlled to be +/-150 mv; after the wastewater is treated by a UF membrane system, discharging the effluent of the UF membrane system into a UF product water tank;

(2f) discharging the effluent of the UF water production tank into a primary RO system, discharging the effluent of the primary RO system into a primary RO water production tank, and discharging the concentrated water generated by the primary RO system into a dyeing wastewater adjusting tank for treatment; one part of water in the primary RO water production tank is recycled as tap water, and the other part of the water is discharged into a secondary RO system;

(3) the treatment method of the dyeing wastewater comprises the following steps:

(3a) independently collecting dyeing wastewater, then feeding the dyeing wastewater into a dyeing wastewater adjusting tank to adjust the water quality and water quantity, then pumping the dyeing wastewater into a third pH adjusting tank, adding sulfuric acid to adjust the pH value to 3-4, carrying out aeration stirring, and discharging effluent into a Fenton reaction tank;

(3b) respectively adding H2O2 and FeSO4 into the Fenton reaction tank to carry out Fenton reaction and aeration stirring, and discharging effluent after the Fenton reaction into a third pH callback tank;

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

(3d) adding a reducing agent NaHSO3 into the third reduction reaction tank, stirring to control the oxidation-reduction potential to be +/-150 mv, and feeding effluent into a third quick mixing tank;

(3e) adding a coagulant polyaluminium chloride PAC into the third fast mixing tank, aerating and stirring to coagulate 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, wherein the particulate matters in the water form large flocs;

(3g) discharging the sewage in the third slow mixing tank into a third inclined tube sedimentation tank for gravity sedimentation, allowing the precipitated sludge to enter a mud bucket and be discharged into a comprehensive sludge concentration tank periodically, performing pressure filtration on the sludge in the concentration tank by using a second box-type pressure filter, transporting the dry sludge outwards, and discharging the filtrate into a phosphorus-containing wastewater adjusting 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 then discharging the effluent into an anaerobic tank in a biochemical system;

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

(3j) discharging the effluent of the aerobic tank into an MBR (membrane bioreactor) membrane tank, filtering the wastewater by using an ultrafiltration membrane assembly, pumping the wastewater into an MBR water production tank, intercepting sludge in the MBR membrane tank, and pumping the intercepted sludge back to the anaerobic tank, the anoxic tank and the aerobic tank; part of water in the MBR water producing tank is discharged into a UF water producing tank of the inorganic wastewater treatment system for reuse water treatment, and the other part of water enters a discharge water pH adjusting tank of a discharge water system for continuous treatment;

(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 a Fenton reaction tank of the discharged water;

(3l) respectively adding H202 and FeSO4 into a discharged water Fenton reaction tank to carry out Fenton reaction and aeration stirring, and enabling the effluent after the Fenton reaction to enter a discharged water pH readjustment tank;

(3m) adding NaOH into the discharged water pH adjusting tank, aerating and stirring, adjusting the pH value to 7-8, and then feeding the discharged water into a discharged water reduction reaction tank;

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

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

(3p) adding a polymeric flocculant PAM into the slow mixing tank of the discharged water, stirring, forming large flocs by particles in the water, discharging the water into a settling tank of the discharged water for gravity settling, allowing the settled sludge to enter a mud bucket, periodically discharging the sludge into a comprehensive sludge concentration tank, carrying out pressure filtration on the sludge in the sludge concentration tank by a second box filter press, then transporting the dry sludge out, and discharging the filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment;

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

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

(4) The treatment method of the phosphorus-containing wastewater comprises the following steps:

(4a) the phosphorus-containing wastewater is separately collected and discharged into a phosphorus-containing wastewater adjusting tank to adjust the water quality and the water quantity, and then the wastewater in the phosphorus-containing wastewater adjusting tank is pumped into a fourth pH adjusting tank in the air floatation device;

(4b) adding NaOH into the fourth pH adjusting tank, aerating and stirring, adjusting the pH value to 9-10, and discharging the discharged water into a fourth phosphorus removal reaction tank in the air flotation device;

(4c) adding a phosphorus removing agent into the fourth phosphorus removing reaction tank, stirring for reaction, and then discharging the wastewater into a fourth slow mixing tank in the air flotation device;

(4d) adding a polymeric flocculant PAM into a fourth slow mixing tank, stirring for flocculation reaction, forming large flocs by particles in water, then discharging wastewater into an air flotation tank in an air flotation device, forming scum by the flocs, scraping the scum into a scum tank, discharging sludge by gravity 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, transporting dry sludge outwards, flowing filtrate into a phosphorus-containing wastewater adjusting tank for continuous treatment, and feeding the discharged water of the air flotation tank into a fourth second pH adjusting tank for continuous dephosphorization reaction;

(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 phosphorus removal reaction tank;

(4f) adding a phosphorus removing agent into the fourth phosphorus removing reaction tank, stirring for reaction, and then discharging the wastewater into a fourth slow mixing tank;

(4g) adding a polymeric flocculant PAM into a fourth second slow mixing tank, mechanically stirring to perform flocculation reaction, forming large flocs by particles in water, then discharging the wastewater into a fourth first primary settling tank for gravity settling, feeding the settled sludge into a sludge hopper, periodically discharging into a comprehensive sludge concentration tank, carrying out filter pressing on the sludge in the sludge concentration tank by a second chamber filter press, transporting dry sludge outwards, discharging the filtrate into a phosphorus-containing wastewater regulating tank for continuous treatment, and discharging the supernatant of the fourth first primary settling tank into a fourth third 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 a coagulant polyaluminium chloride PAC into the fourth fast mixing tank, aerating and stirring, coagulating the precipitated precipitate into larger particles, and discharging the wastewater into a fourth third slow mixing tank;

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

(4k) and performing gravity precipitation on the flocs in a secondary sedimentation tank, allowing the precipitated sludge to enter a sludge hopper and periodically discharge into a comprehensive sludge concentration tank, performing filter pressing on the sludge in the comprehensive sludge concentration tank by using a second box-type filter press, transporting dry sludge outwards, discharging filtrate into a phosphorus-containing wastewater adjusting tank for continuous treatment, discharging supernatant of the secondary sedimentation tank into a fourth intermediate tank for transfer, and pumping wastewater in the fourth intermediate tank into a third pH readjustment tank of the dyeing wastewater treatment system for continuous treatment.

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

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

4. The method for treating anodic oxidation wastewater according to claim 1, wherein the amount of H202 added to the Fenton reaction tank is 100 to 200 mg/L4 and 200 to 300 mg/L, and the stirring and mixing reaction time is 1 hour.

5. The anodic oxidation wastewater treatment method according to claim 1, wherein the mixed solution in the aerobic tank is refluxed to the anoxic tank at a reflux ratio of 100 to 400%.

6. The anodic oxidation wastewater treatment method of claim 1, wherein the phosphorus removal agents added to the fourth phosphorus removal reaction tank and the fourth phosphorus removal reaction tank are FeSO4, and the addition amount is 80-100 mg/L.

7. The method for treating anodic oxidation wastewater according to claim 1, wherein the scale inhibitor added to the third line mixer is L T L D-RO scale inhibitor in an amount of 3 to 5 ppm.

8. An anodizing wastewater treatment system 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,

9. The anodic oxidation wastewater treatment system according to claim 8, wherein the first pH adjustment tank, the first and second pH adjustment tanks, the intermediate clean water tank, the second pH adjustment tank, the first pipeline mixer, the third pH adjustment tank, the third pH adjustment tank, the discharge water pH adjustment tank, the fourth pH adjustment tank, and the fourth pH adjustment tank are all provided with pH on-line control devices.

10. The anodic oxidation wastewater treatment system according to claim 8, wherein ORP on-line control devices are provided in the second line mixer, the third reduction reaction tank, the discharge water recycling tank and the discharge water reduction reaction tank.