阅读说明：本技术 电镀废水零排放处理系统 (Electroplating effluent zero release processing system ) 是由 谭硕文 张俊惠 刘国清 谭鑫 于 2021-07-01 设计创作，主要内容包括：本发明公开了一种电镀废水零排放处理系统,属于电镀废水处理技术领域。该电镀废水零排放处理系统,包括预处理系统、膜处理系统、纯化杀菌(EDI+UV)系统和蒸发浓缩干化系统,其中,预处理系统包括气浮分离系统和还原分离系统,膜分离系统包括1#膜分离系统和2#膜分离系统；将含镍和含铬的废水分开处理,1#膜分离系统和2#膜分离系统的反渗透浓水流向蒸发浓缩干化系统,蒸发浓缩干化系统的蒸馏液返回气浮分离系统循环处理,蒸发浓缩干化系统的危废委外处理,1#膜分离系统和2#膜分离系统的反渗透淡水流向淡水储水箱,再经过纯化杀菌后流向纯水存储箱。实现了废水的大幅回收回用,稳定了产水水质,减少了污泥产生量及危废处理费用。(The invention discloses an electroplating wastewater zero-discharge treatment system, and belongs to the technical field of electroplating wastewater treatment. The electroplating wastewater zero-discharge treatment system comprises a pretreatment system, a membrane treatment system, a purification and sterilization (EDI + UV) system and an evaporation, concentration and drying system, wherein the pretreatment system comprises an air floatation separation system and a reduction separation system, and the membrane separation system comprises a No. 1 membrane separation system and a No. 2 membrane separation system; the method comprises the following steps of separately treating wastewater containing nickel and chromium, enabling reverse osmosis concentrated water of a 1# membrane separation system and a 2# membrane separation system to flow to an evaporation concentration drying system, enabling distillate of the evaporation concentration drying system to return to an air floatation separation system for cyclic treatment, enabling hazardous waste of the evaporation concentration drying system to be treated outside, enabling reverse osmosis fresh water of the 1# membrane separation system and the 2# membrane separation system to flow to a fresh water storage tank, and enabling the reverse osmosis fresh water to flow to a pure water storage tank after purification and sterilization. The waste water is greatly recycled, the quality of the produced water is stabilized, and the sludge production and the hazardous waste treatment cost are reduced.)

1. A zero-discharge treatment system for electroplating wastewater is characterized by comprising a pretreatment system, a membrane separation system, a purification and sterilization system and an evaporation, concentration and drying system, wherein the pretreatment system comprises an air flotation separation system and a reduction separation system, the air flotation separation system is adopted for nickel-containing wastewater and pretreatment wastewater, the reduction separation system is adopted for chromium-containing wastewater treatment, and the membrane separation system comprises a No. 1 membrane separation system and a No. 2 membrane separation system;

the produced water of air supporting piece-rate system flows to 1# membrane separation system, the product water of reduction piece-rate system flows to 2# membrane separation system, 1# membrane separation system and 2# membrane separation system's reverse osmosis dense rivers are to evaporation concentration mummification system, the distillate of evaporation concentration mummification system returns air supporting piece-rate system circulation and handles, the useless commission of solid-state danger of evaporation concentration mummification system is handled outward, the fresh water of 1# membrane separation system and 2# membrane separation system output flows to the fresh water storage tank, flow to the pure water storage tank after purification and sterilization again.

2. The electroplating wastewater zero-discharge treatment system as claimed in claim 1, wherein the air flotation separation system comprises a produced water storage tank (1), a plurality of PH regulation tanks, a plurality of lift pumps, an integrated air flotation machine (5), a scum storage tank (9), a # 1 sludge pump (10), a # 1 filter press (11) and a # 1 sludge collection tank (13), the produced water storage tank (1) is connected to the first PH regulation tank (3) through the first lift pump (2), and then connected to the integrated air flotation machine (5) through the second lift pump (4), the system produced water of the integrated air flotation machine (5) is connected to the second PH regulation tank (7) through the third lift pump (6), and then connected to the # 1 membrane separation system through the fourth lift pump (8); scum of the integrated air flotation machine (5) overflows to a scum storage tank (9), and is connected with a 1# pressure filter (11) through a 1# sludge pump (10), a filtrate outlet of the 1# pressure filter (11) is connected to an evaporation, concentration and drying system, and a filter residue outlet is connected to a 1# sludge collecting tank (13).

3. The electroplating wastewater zero-discharge treatment system according to claim 1, characterized in that the reduction separation system comprises a wastewater storage tank (14), a plurality of lift pumps, a reduction tank (16), a plurality of PH regulation tanks and a sedimentation separator (20), wherein the wastewater storage tank (14) is connected to the reduction tank (16) through a ninth lift pump (15), is connected to a third PH regulation tank (18) through a tenth lift pump (17), is connected to the sedimentation separator (20) through an eleventh lift pump (19), a sedimentation mixture outlet of the sedimentation separator (20) is connected to an evaporation concentration drying system, a supernatant outlet is connected to a fourth fifth PH regulation tank through a twelfth lift pump (21), and the fourth PH regulation tank (22) is connected to a # 2 membrane separation system.

4. The electroplating wastewater zero-emission treatment system as claimed in claim 1, wherein the # 1 membrane separation system comprises a first circulation tank (23), a plurality of lift pumps, a first ultrafiltration system (25), a first buffer tank (29), a first reverse osmosis pump set (30), a # 1 first reverse osmosis system (31), a second buffer tank (32), a second reverse osmosis pump set (33), a # 1 second reverse osmosis system (34), a third buffer tank (36), a third reverse osmosis pump set (37), a # 1 third reverse osmosis system (38), a # 1 activated carbon filter (35), a collecting tank (26), a # 1 wastewater tank (28) and a concentrated water collecting tank (39), the air flotation separation system is connected with the first circulation tank (23) for water supply, the first circulation tank (23) is connected with the first ultrafiltration system (25) through a thirteenth lift pump (24), and a backwashing water outlet of the first ultrafiltration system (25) is connected with the collecting tank (26), A filtrate outlet is connected to a first-stage buffer tank (29), a concentrated water outlet is connected to a circulating tank, a collecting tank (26) is connected to a 1# wastewater tank (28) through a fourteenth lifting pump (27), the first-stage buffer tank (29) is connected to a first-stage reverse osmosis pump set (30) and then connected to a 1# first-stage reverse osmosis system (31), a fresh water outlet of the 1# first-stage reverse osmosis system (31) is connected to a second-stage buffer tank (32), a concentrated water outlet is connected to a third-stage buffer tank (36), the second-stage buffer tank (32) is connected to a second-stage reverse osmosis pump set (33) and then connected to a 1# second-stage reverse osmosis system (34), the third-stage buffer tank (36) is connected to a third-stage reverse osmosis pump set (37) and then connected to a 1# third-stage reverse osmosis system (38), the concentrated water outlet of the 1# second-stage reverse osmosis system (34) is connected to the first-stage buffer tank (29), and the fresh water outlet is connected to a 1# active carbon filter (35), a fresh water outlet of the No. 1 three-stage reverse osmosis system (38) is connected to the first-stage buffer tank (29), a concentrated water outlet is connected to the concentrated water collecting tank (39), and a solid waste outlet of the No. 1 activated carbon filter (35) is connected to the evaporation, concentration and drying system.

5. The electroplating wastewater zero-emission treatment system as claimed in claim 1, wherein the # 2 membrane separation system comprises a second circulation tank (40), a second ultrafiltration system (41), a # 1 buffer tank (42), a # 2 primary reverse osmosis system (43), a # 2 buffer tank (44), a # 2 secondary reverse osmosis system (45), a # 3 buffer tank (47), a # 2 tertiary reverse osmosis system (48), a # 2 activated carbon filter (46) and a # 2 wastewater tank, the reduction separation system is connected with the second circulation tank (40), the second circulation tank (40) is connected with the second ultrafiltration system (41), a concentrated water outlet of the second ultrafiltration system (41) is connected with the second circulation tank (40), a filtrate outlet is connected with the # 1 buffer tank (42) and then connected with the # 2 primary reverse osmosis system (43), a fresh water outlet of the # 2 primary reverse osmosis system (43) is connected with the # 2 buffer tank (44), The concentrated water outlet is connected to the 3# buffer tank (47), the 2# buffer tank (44) is connected to the 2# second-stage reverse osmosis system (45), the concentrated water outlet of the 2# second-stage reverse osmosis system (45) is connected to the 1# buffer tank (42), the fresh water outlet is connected to the 2# active carbon filter (46), the 3# buffer tank (47) is connected to the 2# third-stage reverse osmosis system (48), the concentrated water outlet of the 2# third-stage reverse osmosis system (48) is connected to the 2# waste water tank, the fresh water outlet is connected to the 1# buffer tank (42), the insoluble substance outlet of the 2# active carbon filter (46) is connected to the evaporation concentration drying system, the water output is connected to the purification and sterilization system, and the insoluble substance outlet of the circulating tank is connected to the evaporation concentration drying system.

6. The electroplating wastewater zero-discharge treatment system as claimed in claim 1, wherein the purification and sterilization system comprises a reverse osmosis water storage tank (49), a fifteenth lift pump (50), an ultraviolet sterilization device (51), an electrodialysis and ion exchange multi-membrane stack (52), a pure water storage tank (53) and a sixteenth lift pump (54) which are connected in sequence, incoming water of the 1# membrane separation system and the 2# membrane separation system is connected to the reverse osmosis water storage tank (49), a concentrated water outlet of the electrodialysis and ion exchange multi-membrane stack (52) is connected to a circulating tank of the 1# membrane separation system or the 2# membrane separation system, and the sixteenth lift pump (54) is connected to the electroplating line recycling production line.

7. The electroplating wastewater zero-emission treatment system according to claim 1, wherein the evaporation concentration drying system comprises a wastewater collection tank (55), a fifth PH regulation tank (57), a plurality of lift pumps, a 2# sludge pump (58), a 2# filter press (59), a filtrate collection tank (60), a concentration evaporation device (62), a concentrated solution collection tank (63), a concentration crystallization device (65), a 2# sludge collection tank (66) and a sludge drying device (68), the wastewater collection tank (55) is connected to the fifth PH regulation tank (57) through a seventeenth lift pump (56) and is connected to the 2# filter press (59) through the 2# sludge pump (58), a filtrate outlet of the 2# filter press (59) is connected to the filtrate collection tank (60) and a filter cake outlet is connected to the 2# sludge collection tank (66), the filtrate collection tank (60) is connected to the concentration evaporation device (62) through an eighteenth lift pump (61), a concentrated solution outlet of the concentrated evaporation equipment (62) is connected to a concentrated solution collecting tank (63) and then connected to concentrated crystallization equipment (65) through a nineteenth lifting pump (64); the solid matter outlet of the concentration and crystallization device (65) is connected to a No. 2 sludge collecting tank (66) and is connected to a sludge drying device (68) through a twentieth lifting pump (67).

8. The electroplating wastewater zero-emission treatment system as claimed in claim 7, wherein the distillate outlet of the concentration evaporation device (62), the distillate outlet of the concentration crystallization device (65) and the distillate outlet of the sludge drying device (68) are all connected to a distillate collection tank, and the distillate collection tank is connected to the air flotation separation system.

9. The electroplating wastewater zero-discharge treatment system according to claim 7, characterized in that the concentration evaporation equipment (62) is mechanical vapor compression type low-temperature vacuum concentration evaporation equipment (62), the concentration crystallization equipment (65) is mechanical vapor compression type low-temperature vacuum concentration crystallization equipment (65), and the sludge drying equipment (68) is low-temperature sludge drying equipment (68).

10. The zero discharge treatment system for wastewater from electroplating according to claim 7, wherein the fifth pH adjustment tank (57) is capable of adjusting the pH of the solution to be greater than 8.

Technical Field

The invention relates to the technical field of electroplating wastewater treatment, in particular to an electroplating wastewater zero-discharge treatment system.

Background

A large amount of waste water containing heavy metals, acids, alkalis and high COD organic matters is generated in the electroplating production process, the harm to the environment is large, the waste water can be discharged only after being strictly treated and reaching the standard, and a large amount of water resources are consumed in the electroplating production process.

In the traditional methods for treating electroplating wastewater by a chemical method, an electrolytic method and the like, a certain amount of chemicals are added in the treatment process, and even if the items such as heavy metal, COD (chemical demand) and the like reach the discharge standard, TDS (total dissolved solids/total salt content) in the treated wastewater hardly reaches the discharge standard which is less than 1600 specified by the state (although the index is not forcibly required in many places), so that salinization of water and soil can be caused after long-term discharge, and the consequences are also serious.

In the prior electroplating wastewater zero-discharge treatment process, the problems of high energy consumption, high operating cost, low water reuse rate, low water quality of produced water, easy generation of microorganisms for long-term recycling of water, odor and deterioration, need of regular replacement of fresh water and the like exist in different degrees.

Therefore, it is desirable to provide a zero discharge treatment system for electroplating wastewater to solve the above technical problems.

Disclosure of Invention

The invention aims to provide an electroplating wastewater zero-discharge treatment system, which realizes the large-scale recovery and reuse of wastewater, ensures that the conductivity of the produced water of the system is less than 20us/cm, has high quality of the produced water and low treatment cost, and can greatly reduce the sludge production and the treatment cost of hazardous waste.

In order to realize the purpose, the following technical scheme is provided:

the invention provides an electroplating wastewater zero-discharge treatment system which comprises a pretreatment system, a membrane separation system, a purification and sterilization system, an evaporation concentration and drying system and a purification and sterilization system, wherein the pretreatment system comprises an air flotation separation system and a reduction separation system, the air flotation separation system is adopted for nickel-containing wastewater pretreatment, the reduction separation system is adopted for chromium-containing wastewater treatment, and the membrane separation system comprises a No. 1 membrane separation system and a No. 2 membrane separation system;

the produced water of the air flotation separation system flows to the 1# membrane separation system, the produced water of the reduction separation system flows to the 2# membrane separation system, the reverse osmosis concentrated water flows of the 1# membrane separation system and the 2# membrane separation system to the evaporation concentration drying system, distillate of the evaporation concentration drying system returns to the air flotation separation system for cyclic treatment, the danger of the evaporation concentration drying system is wasted, the reverse osmosis fresh water flows of the 1# membrane separation system and the 2# membrane separation system to the fresh water storage tank, and the water flows to the pure water storage tank after purification and sterilization.

Further, the air floatation separation system comprises a produced water storage tank, a plurality of PH adjusting tanks, a plurality of lift pumps, an integrated air floatation machine, a scum storage tank, a # 1 sludge pump, a # 1 pressure filter and a # 1 sludge collecting tank, wherein the produced water storage tank is connected to the first PH adjusting tank through the first lift pump and then connected to the integrated air floatation machine through the second lift pump, and system produced water of the integrated air floatation machine is connected to the second PH adjusting tank through the third lift pump and then connected to the # 1 membrane separation system through the fourth lift pump; the scum of integration air supporting machine overflows to the scum holding tank, connects 1# pressure filter through 1# sludge pump, and the filtrating export of 1# pressure filter is connected to evaporation concentration mummification system, filter residue exit linkage to 1# sludge collecting vat.

Furthermore, the reduction separation system comprises a wastewater storage tank, a plurality of lifting pumps, a reduction tank, a plurality of PH regulation tanks and a sedimentation separator, wherein the wastewater storage tank is connected to the reduction tank through a ninth lifting pump, then connected to a third PH regulation tank through a tenth lifting pump, and then connected to the sedimentation separator through an eleventh lifting pump, a sedimentation mixture outlet of the sedimentation separator is connected to the evaporation concentration drying system, a supernatant outlet is connected to a fourth fifth PH regulation tank through a twelfth lifting pump, and the fourth PH regulation tank is connected to the No. 2 membrane separation system.

Further, the 1# membrane separation system comprises a first circulation tank, a plurality of lifting pumps, a first ultrafiltration system, a first-stage buffer tank, a first-stage reverse osmosis pump set, a 1# first-stage reverse osmosis system, a second-stage buffer tank, a second-stage reverse osmosis pump set, a 1# second-stage reverse osmosis system, a third-stage buffer tank, a third-stage reverse osmosis pump set, a 1# third-stage reverse osmosis system, a 1# active carbon filter, a collecting tank, a 1# waste water tank and a concentrated water collecting tank, wherein the incoming water of the air floatation separation system is connected to the first circulation tank, the first circulation tank is connected to the first ultrafiltration system through a thirteenth lifting pump, a reverse washing water outlet of the first ultrafiltration system is connected to the collecting tank, a filtrate outlet is connected to the first-stage buffer tank, a concentrated water outlet is connected to the circulation tank, the collecting tank is connected to the 1# waste water tank through a fourteenth lifting pump, the first-stage reverse osmosis pump set is connected to the first-stage reverse osmosis buffer tank, and then connected to the 1# first-stage reverse osmosis buffer system, 1# one-level reverse osmosis system's fresh water outlet is connected to the second grade dashpot, dense water outlet is connected to tertiary dashpot, the second grade dashpot is connected to second grade reverse osmosis pump package, reconnect to 1# second grade reverse osmosis system, tertiary dashpot is connected to tertiary reverse osmosis pump package, reconnect to 1# tertiary reverse osmosis system, 1# second grade reverse osmosis system's dense water outlet is connected to the one-level dashpot, the fresh water outlet is connected to 1# active carbon filter, 1# tertiary reverse osmosis system's fresh water outlet is connected to the one-level dashpot, dense water outlet is connected to the dense water collecting vat, 1# active carbon filter's solid waste exit linkage to evaporation concentration mummification system.

Furthermore, the 2# membrane separation system comprises a second circulation tank, a second ultrafiltration system, a 1# buffer tank, a 2# first-stage reverse osmosis system, a 2# buffer tank, a 2# second-stage reverse osmosis system, a 3# buffer tank, a 2# third-stage reverse osmosis system, a 2# active carbon filter and a 2# waste water tank, wherein the reduction separation system is connected with the second circulation tank through water, the second circulation tank is connected with the second ultrafiltration system, a concentrated water outlet of the second ultrafiltration system is connected with the second circulation tank, a filtrate outlet is connected with the 1# buffer tank and then connected with the 2# first-stage reverse osmosis system, a fresh water outlet of the 2# first-stage reverse osmosis system is connected with the 2# buffer tank, a concentrated water outlet is connected with the 3# buffer tank, the 2# buffer tank is connected with the 2# second-stage reverse osmosis system, a concentrated water outlet of the 2# second-stage reverse osmosis system is connected with the 1# buffer tank, and a fresh water outlet is connected with the 2# active carbon filter, the 3# buffer tank is connected to the 2# tertiary reverse osmosis system, and the concentrated water outlet of the 2# tertiary reverse osmosis system is connected to the 2# waste water tank, the fresh water outlet is connected to the 1# buffer tank, and the insoluble substance export of the 2# active carbon filter and being connected to the evaporation concentration drying system, the product water outlet is connected to the purification sterilization system, and the insoluble substance export of the second circulation tank is connected to the evaporation concentration drying system.

Further, the purification and sterilization system comprises a reverse osmosis water storage tank, a fifteenth lift pump, an ultraviolet sterilization device, an electrodialysis and ion exchange multi-element membrane stack, a pure water storage tank and a sixteenth lift pump which are sequentially connected, water from the 1# membrane separation system and the 2# membrane separation system is connected to the reverse osmosis water storage tank, a concentrated water outlet of the electrodialysis and ion exchange multi-element membrane stack is connected to a circulation tank of the 1# membrane separation system or the 2# membrane separation system, and the sixteenth lift pump is connected to the electroplating line recycling production line.

Further, the evaporation concentration drying system comprises a wastewater collecting tank, a fifth PH regulating tank, a plurality of lifting pumps, a 2# sludge pump, a 2# filter press, a filtrate collecting tank, a concentration evaporation device, a concentrated solution collecting tank, a concentration crystallization device, a 2# sludge collecting tank and a sludge drying device, wherein the wastewater collecting tank is connected to the fifth PH regulating tank through a seventeenth lifting pump and then connected to the 2# filter press through the 2# sludge pump, a filtrate outlet of the 2# filter press is connected to the filtrate collecting tank, a filter cake outlet is connected to the 2# sludge collecting tank, the filtrate collecting tank is connected to the concentration evaporation device through an eighteenth lifting pump, a concentrated solution outlet of the concentration evaporation device is connected to the concentrated solution collecting tank, and then connected to the concentration crystallization device through a nineteenth lifting pump; and a solid matter outlet of the concentration and crystallization device is connected to a No. 2 sludge collecting tank and is connected to a sludge drying device through a twentieth lifting pump.

Further, a distillate outlet of the concentration evaporation equipment, a distillate outlet of the concentration crystallization equipment and a distillate outlet of the sludge drying equipment are connected to a distillate collecting tank, and the distillate collecting tank is connected to the air flotation separation system.

Furthermore, the concentration evaporation equipment is mechanical vapor compression type low-temperature vacuum concentration evaporation equipment, the concentration crystallization equipment is mechanical vapor compression type low-temperature vacuum concentration crystallization equipment, and the sludge drying equipment is low-temperature sludge drying equipment.

Further, the fifth pH adjusting tank can adjust the pH value of the solution to be more than 8.

Compared with the prior art, the electroplating wastewater zero-discharge treatment system comprises a nickel and chromium-containing heavy metal wastewater pretreatment system, a membrane separation system, a purification and sterilization system and an evaporation concentration and drying system, wherein a three-level RO (reverse osmosis) system, an MVR (mechanical vapor compression) vacuum concentration and evaporation device, an MVR vacuum crystallization device and a sludge drying device are combined in a multi-cycle manner, so that the wastewater is recycled to the maximum extent, and the cost for evaporation treatment of ton water is reduced to be below 60 yuan due to the introduction of the high-efficiency low-energy-consumption MVR vacuum concentration and evaporation device and the MVR vacuum crystallization device; an EDI membrane stack and UV sterilization equipment are introduced, so that the quality of produced water is further stabilized, and the water is ensured to be recycled for a long time without breeding bacterial microorganisms and going bad; the concentration crystallization equipment and the sludge drying equipment can control the water content of the sludge to be below 15 percent, liquid hazardous waste is not generated, the conductivity of the produced water of the system is less than 20us/cm, the quality of the produced water is high, the treatment cost is low (the comprehensive cost of wastewater treatment can be controlled to be 30-50 yuan/ton), and the sludge production and the hazardous waste treatment cost are greatly reduced. After the electroplating wastewater zero-discharge treatment system disclosed by the invention is used for treating the electroplating wastewater, the quality of produced reuse water is less than 20us/cm, the water reuse rate reaches more than 99.7%, and the electroplating wastewater is not deteriorated after being recycled for a long time. The system comprises a high-COD high-TDS (soluble total solids) wastewater concentration separation technology, a high-reuse-rate membrane separation and EDI (electrodialysis and ion exchange multi-element membrane stack), a UV (ultraviolet) combination technology and a high-efficiency drying concentration crystallization technology, more than 99.7% of treated wastewater is reused for an electroplating line, the conductivity of produced water is less than 10us/cm, and resource saving and zero discharge of electroplating wastewater are realized.

Drawings

FIG. 1 is a schematic view of a zero discharge treatment system for electroplating wastewater in an embodiment of the invention;

FIG. 2 is a schematic view of an air flotation separation system in an embodiment of the invention;

FIG. 3 is a schematic view of a reduction separation system according to an embodiment of the present invention;

FIG. 4 is a schematic view of a 1# membrane separation system in an example of the present invention;

FIG. 5 is a schematic diagram of a # 2 membrane separation system in an example of the present invention;

FIG. 6 is a schematic view of a purification and sterilization system in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of an evaporation, concentration and drying system according to an embodiment of the present invention.

Reference numerals:

1-a water producing storage tank; 2-a first lift pump; 3-a first PH adjustment tank; 4-a second lift pump; 5-integrated air flotation machine; 6-a third lift pump; 7-a second pH adjusting tank; 8-a fourth lift pump; 9-a scum storage tank; 10-1# sludge pump; 11-1# filter press; 12-a fifth lift pump; 13-1# sludge collection tank;

14-a wastewater holding tank; 15-a ninth lift pump; 16-a reduction tank; 17-a tenth lift pump; 18-third PH adjustment tank; 19-an eleventh lift pump; 20-a settling separator; 21-a twelfth lift pump; 22-fourth PH adjustment tank;

23-a first circulation tank; 24-a thirteenth lift pump; 25-a first ultrafiltration system; 26-a collection tank; 27-a fourteenth lift pump; 28-1# wastewater tank; 29-primary buffer tank; 30-first-stage reverse osmosis pump set; 31-1# first-stage reverse osmosis system; 32-a secondary buffer tank; 33-a secondary reverse osmosis pump set; 34-1# second stage reverse osmosis system; 35-1# activated carbon filter; 36-a tertiary buffer tank; 37-three-stage reverse osmosis pump set; 38-1# three-stage reverse osmosis system; 39-concentrated water collecting tank;

40-a second circulation tank; 41-a second ultrafiltration system; 42-1# buffer tank; 43-2# first-stage reverse osmosis system; 44-2# buffer tank; 45-2# second-stage reverse osmosis system; 46-2# activated carbon filter; 47-3# buffer tank; 48-2# three-stage reverse osmosis system;

49-reverse osmosis water storage tank; 50-a fifteenth lift pump; 51-ultraviolet sterilization equipment; 52-electrodialysis and ion exchange multi-element membrane stack; 53-pure water storage tank; 54-a sixteenth lift pump;

55-a wastewater collection tank; 56-a seventeenth lift pump; 57-fifth PH adjustment tank; 58-2# sludge pump; 59-2# filter press; 60-filtrate collection tank; 61-eighteenth lift pump; 62-concentration and evaporation equipment; 63-concentrated solution collecting tank; 64-a nineteenth lift pump; 65-a concentration crystallization device; 66-2# sludge collection tank; 67-twentieth lift pump; 68-sludge drying equipment.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the embodiment provides an electroplating wastewater zero-discharge treatment system, which includes a pretreatment system, a membrane treatment system, a purification and sterilization (EDI + UV) system, and an evaporation, concentration and drying system, wherein the pretreatment system includes an air flotation separation system and a reduction separation system, the nickel-containing wastewater is pretreated by the air flotation separation system, the chromium-containing wastewater is treated by the reduction separation system, and the membrane separation system includes a # 1 membrane separation system and a # 2 membrane separation system; the produced water of the air flotation separation system flows to the No. 1 membrane separation system, the produced water of the reduction separation system flows to the No. 2 membrane separation system, the reverse osmosis concentrated water flows to the evaporation concentration drying system of the No. 1 membrane separation system and the No. 2 membrane separation system, the distillate of the evaporation concentration drying system returns to the air flotation separation system for circular treatment, the danger of the evaporation concentration drying system is wasted, the reverse osmosis fresh water flows to the fresh water storage tank of the No. 1 membrane separation system and the No. 2 membrane separation system, and the water flows to the pure water storage tank 53 after being purified and sterilized.

Further, as shown in fig. 2, the air flotation separation system comprises a produced water storage tank 1, a plurality of PH adjustment tanks, a plurality of lift pumps, an integrated air flotation machine 5, a scum storage tank 9, a # 1 sludge pump 10, a # 1 filter press 11 and a # 1 sludge collection tank 13, wherein the produced water storage tank 1 is connected to the first PH adjustment tank 3 through the first lift pump 2 and then connected to the integrated air flotation machine 5 through the second lift pump 4, and the system produced water of the integrated air flotation machine 5 is connected to the second PH adjustment tank 7 through the third lift pump 6 and then connected to the # 1 membrane separation system through the fourth lift pump 8; scum of the integrated air flotation machine 5 overflows to a scum storage tank 9, and is connected with a 1# filter press 11 through a 1# sludge pump 10, and a filtrate outlet of the 1# filter press 11 is connected to an evaporation concentration drying system and a filter residue outlet is connected to a 1# sludge collecting tank 13.

The integrated air floatation system realizes the large-scale recovery and reuse of waste water, stabilizes the quality of produced water and greatly reduces the sludge production amount and the treatment cost of hazardous waste.

Wherein, the liquid in the integrated air flotation machine 5 contains a flocculating agent to continuously remove scum. The No. 1 sludge collecting tank 13 is connected to an evaporation, concentration and drying system. The integrated air flotation machine 5 adjusts the PH value through a sodium hydroxide solution and polyaluminium chloride and keeps the PH value at 8-10. The second pH adjusting tank 7 adjusts pH by using sulfuric acid and sodium hydroxide, and the pH stable value of the second pH adjusting tank 7 is in the range of 6 to 9. The filtrate outlet of the No. 1 filter press 11 is connected to an evaporation, concentration and drying system through a fifth lift pump 12. Specifically, the filtrate outlet of the # 1 filter press 11 is connected to the wastewater recovery tank of the evaporation, concentration and drying system through a fifth lift pump 12. The No. 1 sludge collecting tank 13 is connected to a sludge recovery tank of the evaporation, concentration and drying system.

The produced water storage tank 1 of the embodiment receives nickel recovery produced water and pre-plating treatment rinsing wastewater, and specifically, the technological process of the air flotation separation system is as follows:

the method comprises the following steps that the produced water of a nickel recovery system and the rinsing wastewater before plating flow into a produced water storage tank 1, the produced water is sequentially pumped into a first PH adjusting tank 3 through a first lifting pump 2, the PH is adjusted to be up, the produced water flows into an integrated air floatation machine 5 through a second lifting pump 4, the PH is adjusted through sodium hydroxide and polyaluminium chloride and is kept at 8-10, the produced water of the integrated air floatation machine 5 is pumped into a second PH adjusting tank 7 through a third lifting pump 6, the PH is adjusted to be 6-9 through sulfuric acid and sodium hydroxide, and the produced water is pumped into a membrane separation system storage tank through a fourth lifting pump 8; scum generated by the integrated air flotation machine 5 overflows to a scum storage tank 9, is pumped into a filter press by a 1# sludge pump 10 for solid-liquid separation, separated filtrate is pumped into a wastewater recovery tank of the evaporation concentration drying system by a fifth lift pump 12 for further treatment, and separated sludge is collected in a 1# sludge collecting tank 13 and then is further treated in a 2# sludge collecting tank 66 of the evaporation concentration drying system.

Further, referring to fig. 3, the reduction separation system includes a wastewater storage tank 14, a plurality of lift pumps, a reduction tank 16, a plurality of PH adjustment tanks, and a settling separator 20, the wastewater storage tank 14 is connected to the reduction tank 16 by a ninth lift pump 15, is connected to a third PH adjustment tank 18 by a tenth lift pump 17, is connected to the settling separator 20 by an eleventh lift pump 19, a settled mixture outlet of the settling separator 20 is connected to an evaporation concentration drying system, a supernatant outlet is connected to a fourth PH adjustment tank 22 by a twelfth lift pump 21, and the fourth PH adjustment tank 22 is connected to a # 2 membrane separation system.

The wastewater storage tank 14 of the embodiment receives the chromium-containing wastewater, and specifically, the technological process of the reduction separation system is as follows:

the chromium-containing wastewater flows into a wastewater storage tank 14, is pumped to a reduction tank 16 by a ninth lift pump 15, is completely reduced into trivalent chromium by pH value adjustment by sulfuric acid and sodium metabisulfite, is connected to a third pH adjusting tank 18 by a tenth lift pump 17, is pumped to a sedimentation separator 20 by an eleventh lift pump 19 after pH adjustment by sodium hydroxide and sulfuric acid reaches 10.4, flows to a 2# membrane separation system for treatment after pH adjustment by a twelfth lift pump 21 to a fourth pH adjusting tank 22, and is removed from a 2# sludge collecting tank 66 of an evaporation concentration drying system.

Further, as shown in FIG. 4, the # 1 membrane separation system includes a first circulation tank 23, a plurality of lift pumps, a first ultrafiltration system 25, a first stage buffer tank 29, a first stage reverse osmosis pump set 30, a # 1 first stage reverse osmosis system 31, a second stage buffer tank 32, a second stage reverse osmosis pump set 33, a # 1 second stage reverse osmosis system 34, a third stage buffer tank 36, a third stage reverse osmosis pump set 37, a # 1 third stage reverse osmosis system 38, a # 1 activated carbon filter 35, a collection tank 26, a # 1 waste water tank 28, and a concentrate collection tank 39, the air flotation separation system is connected to the first circulation tank 23 for water, the first circulation tank 23 is connected to the first ultrafiltration system 25 through a thirteenth lift pump 24, a reverse osmosis outlet of the first ultrafiltration system 25 is connected to the collection tank 26, a filtrate outlet is connected to the first stage buffer tank 29, a concentrate outlet is connected to the first circulation tank 23, the rinse water 26 is connected to the # 1 waste water tank 28 through a fourteenth lift pump 27, the first-stage buffer tank 29 is connected to the first-stage reverse osmosis pump set 30 and then connected to the first-stage reverse osmosis system 31 No. 1, a fresh water outlet of the first-stage reverse osmosis system 31 No. 1 is connected to the second-stage buffer tank 32, a concentrated water outlet of the concentrated water outlet is connected to the third-stage buffer tank 36, the second-stage buffer tank 32 is connected to the second-stage reverse osmosis pump set 33 and then connected to the second-stage reverse osmosis system 34, the third-stage buffer tank 36 is connected to the third-stage reverse osmosis pump set 37 and then connected to the third-stage reverse osmosis system 38 No. 1, a concentrated water outlet of the second-stage reverse osmosis system 34 is connected to the first-stage buffer tank 29, a fresh water outlet of the fresh water outlet is connected to the activated carbon filter 35 No. 1, a fresh water outlet of the third-stage reverse osmosis system 38 is connected to the first-stage buffer tank 29, a concentrated water outlet of the concentrated water outlet is connected to the concentrated water 39, and solid waste outlet of the activated carbon filter collecting tank 35 No. 1 is connected to the evaporation, concentration and drying system.

The ultrafiltration is a highly standardized and highly integrated ultrafiltration membrane filtration system, the first ultrafiltration system 25 is a TFS-OF system, the 1# first-stage reverse osmosis system 31 is a first-stage ultrahigh pressure special reverse osmosis (TFS-SIRO) membrane group, the 1# second-stage reverse osmosis system 34 is a second-stage ultrahigh pressure special reverse osmosis (TFS-SIRO) membrane group, and the 1# third-stage reverse osmosis system 38 is a third-stage ultrahigh pressure special reverse osmosis (TFS-SIRO) membrane group.

The first circulation tank 23 of the present embodiment receives the nickel-containing wastewater, and specifically, the process of the # 1 membrane separation system is as follows:

the nickel-containing wastewater pretreated by the air floatation separation system enters a first TFS-OF ultrafiltration system from a first circulation tank 23 through a thirteenth lift pump 24, the produced water OF the first TFS-OF ultrafiltration system enters a first-stage buffer tank 29, concentrated water is returned to the circulation tank for circulation treatment, and ultrafiltration membrane backwashing water is returned to a wastewater tank No. 1 28 for circulation treatment through a collection tank 26 and a fourteenth lift pump 27. The ultrafiltration produced water enters a No. 1 first-level reverse osmosis system 31 through a first-level reverse osmosis pump set 30, the first-level produced water enters a second-level buffer tank 32, and the first-level concentrated water enters a third-level buffer tank 36. The first-stage produced water enters a No. 1 second-stage reverse osmosis system 34 through a second-stage reverse osmosis pump set 33, organic substances in the second-stage produced water are further removed through a No. 1 active carbon filter 35, the second-stage produced water enters an RO water storage tank and then goes to a purification and sterilization system, and solid waste filtered by the No. 1 active carbon filter 35 goes to an evaporation, concentration and drying system; the second-level concentrated water returns to the first-level buffer tank 29 for circular treatment. The first-level concentrated water enters a No. 1 third-level reverse osmosis system 38 through a third-level reverse osmosis pump set 37, third-level produced water returns to the first-level buffer tank 29 for circular treatment, and the third-level concentrated water is collected by a concentrated water collecting tank 39 and then is further treated by an evaporation concentration drying system.

Further, referring to fig. 5, the # 2 membrane separation system includes a second circulation tank 40, a second ultrafiltration system 41, a # 1 buffer tank 42, a # 2 primary reverse osmosis system 43, a # 2 buffer tank 44, a # 2 secondary reverse osmosis system 45, a # 3 buffer tank 47, a # 2 tertiary reverse osmosis system 48, a # 2 activated carbon filter 46 and a # 2 waste water tank, the reduction separation system is connected with the second circulation tank 40 for incoming water, the second circulation tank 40 is connected to the second ultrafiltration system 41, a concentrate outlet of the second ultrafiltration system 41 is connected to the second circulation tank 40, a filtrate outlet is connected to the # 1 buffer tank 42 and is further connected to the # 2 primary reverse osmosis system 43, a fresh water outlet of the # 2 primary reverse osmosis system 43 is connected to the # 2 buffer tank 44, a concentrate outlet is connected to the # 3 buffer tank 47, the # 2 buffer tank 44 is connected to the # 2 secondary reverse osmosis system 45, a concentrate outlet of the # 2 secondary reverse osmosis system 45 is connected to the # 1 buffer tank 42, a concentrate outlet of the # 2 secondary reverse osmosis system 45 is connected to the # buffer tank 42, The fresh water outlet is connected to the # 2 activated carbon filter 46, the # 3 buffer tank 47 is connected to the # 2 three-stage reverse osmosis system 48, the concentrated water outlet of the # 2 three-stage reverse osmosis system 48 is connected to the # 2 waste water tank, the fresh water outlet is connected to the # 1 buffer tank 42, the insoluble substance outlet of the # 2 activated carbon filter 46 is connected to the evaporation concentration drying system, the produced water outlet is connected to the purification sterilization system, and the insoluble substance outlet of the circulating tank is connected to the evaporation concentration drying system.

Similarly, the second ultrafiltration system 41 is a TFS-OF system, the 2# first-stage reverse osmosis system 43 is a first-stage ultrahigh pressure special reverse osmosis (TFS-SIRO) membrane module, the 2# second-stage reverse osmosis system 45 is a second-stage ultrahigh pressure special reverse osmosis (TFS-SIRO) membrane module, and the 2# third-stage reverse osmosis system 48 is a third-stage ultrahigh pressure special reverse osmosis (TFS-SIRO) membrane module.

The second circulation tank 40 of this embodiment receives the chromium-containing wastewater, and specifically, the process of the # 2 membrane separation system is as follows:

the water produced by the second circulation tank 40 of the chromium-containing wastewater pretreated by the reduction separation system enters a second ultrafiltration system 41, suspended insoluble substances are evaporated, concentrated and dried, the water produced by the second ultrafiltration system 41 enters a No. 1 buffer tank 42, and concentrated water returns to the circulation tank for circulation treatment. The ultrafiltration produced water enters a No. 2 first-stage reverse osmosis system 43, the permeated first-stage fresh water enters a No. 2 buffer tank 44, and the first-stage concentrated water enters a No. 3 buffer tank 47. The water produced by the No. 2 buffer tank 44 enters a No. 2 secondary reverse osmosis system 45, the permeated secondary fresh water is further subjected to organic matter removal through a No. 2 activated carbon filter 46, then enters an RO water storage tank and then enters a purification and sterilization system, and insoluble substances filtered by the No. 2 activated carbon filter 46 enter an evaporation, concentration and drying system; the second concentrated water is returned to the 1# buffer tank 42 for circular treatment. The water produced by the 3# buffer tank 47 enters a 2# three-stage reverse osmosis system 48, the three-stage fresh water after permeation returns to the 1# buffer tank 42 for circular treatment, and the three-stage concentrated water goes to a 2# waste water tank for collection.

Further, as shown in fig. 6, the purification and sterilization system includes a reverse osmosis water storage tank 49, a fifteenth lift pump 50, an Ultraviolet (UV) sterilization device, an electrodialysis and ion exchange multi-membrane stack 52(EDI membrane stack), a pure water storage tank 53 and a sixteenth lift pump 54 which are connected in sequence, the incoming water of the 1# membrane separation system and the 2# membrane separation system is connected to the reverse osmosis water storage tank 49, the concentrated water outlet of the electrodialysis and ion exchange multi-membrane stack 52 is connected to the circulation tank of the 1# membrane separation system or the 2# membrane separation system, and the sixteenth lift pump 54 is connected to the plating line recycling production line.

Wherein the reverse osmosis water storage tank 49 is the above RO water storage tank, and the sixteenth lift pump 54 is a constant pressure lift pump.

The process of the purification and sterilization system of the embodiment is as follows:

the water produced by the 1# membrane separation system and the 2# membrane separation system enters ultraviolet sterilization equipment 51 through a reverse osmosis water storage tank 49 and a fifteenth lift pump 50, the sterilized water produced enters an EDI membrane stack for further purification, the water produced by the EDI membrane stack enters a pure water storage tank 53, the water is recycled to an electroplating line through a sixteenth lift pump 54, and the concentrated water of the EDI membrane stack is collected and then enters a membrane system circulation tank again for circulation treatment.

Further, referring to FIG. 7, the evaporation, concentration and drying system comprises a wastewater collection tank 55, a fifth pH adjustment tank 57, a plurality of lift pumps, a # 2 sludge pump 58, a # 2 filter press 59, and a filtrate collection tank 60, the concentrated evaporation device 62, the concentrated solution collecting tank 63, the concentrated crystallization device 65, the # 2 sludge collecting tank 66 and the sludge drying device 68, the wastewater collecting tank 55 is connected to the fifth PH adjusting tank 57 through the seventeenth lift pump 56, and then connected to the # 2 filter press 59 through the # 2 sludge pump 58, the filtrate outlet of the # 2 filter press 59 is connected to the filtrate collecting tank 60, the filter cake outlet is connected to the # 2 sludge collecting tank 66, the filtrate collecting tank 60 is connected to the concentrated evaporation device 62 through the eighteenth lift pump 61, the concentrated solution outlet of the concentrated evaporation device 62 is connected to the concentrated solution collecting tank 63, and then connected to the concentrated crystallization device 65 through the nineteenth lift pump 64; the solid outlet of the concentration and crystallization device 65 is connected to a No. 2 sludge collecting tank 66 and is connected to a sludge drying device 68 through a twentieth lifting pump 67.

Preferably, a distillate outlet of the concentration evaporation equipment 62, a distillate outlet of the concentration crystallization equipment 65 and a distillate outlet of the sludge drying equipment 68 are connected to a distillate collecting tank, and the distillate collecting tank is connected to the air flotation separation system. Specifically, the distillate collecting tank returns to the wastewater collecting tank 55 of the air floatation separation system through the lift pump for cyclic treatment, and the heavy solid-liquid separation treatment greatly improves the recovery and reuse rate of wastewater of the electroplating wastewater zero-discharge treatment system, and stabilizes the quality of produced water.

Optionally, a sludge outlet of the sludge drying device 68 is connected to a sludge outsourcing treatment system outside the system, and the finally discharged sludge is solid hazardous waste with the water content of about 9-14% after heavy dehydration and drying treatment of the concentration evaporation device 62, the concentration crystallization device 65 and the sludge drying device 68, and then is discharged for external treatment, so that the hazard is low, and the sludge production and hazardous waste treatment cost are greatly reduced.

Preferably, the fifth PH adjusting tank 57 adjusts the PH of the wastewater liquid entering the concentration and evaporation equipment 62 to be more than 8 in order to avoid corrosion of the concentration and evaporation equipment 62. Optionally, in order to improve the effect of concentration and dehydration, the concentration and evaporation equipment 62 is a mechanical vapor compression type low-temperature vacuum concentration and evaporation equipment which has the characteristics of low operation cost, high efficiency, high concentration ratio and the like, the operation cost of distilling 1 ton of wastewater is only about 60 yuan, and the concentration ratio can reach 95%. The concentration and crystallization device 65 is a mechanical vapor compression type low-temperature vacuum concentration and crystallization device 65, and the sludge drying device 68 is a low-temperature sludge drying device.

The technological process of the evaporation, concentration and drying system of the embodiment is as follows:

all high COD's such as plating line deoiling degreasing solution concentrated waste water, laboratory waste water, other thick waste water of synthesizing collect waste water collecting vat 55, get into fifth PH adjusting tank 57 through seventeenth elevator pump 56, for avoiding causing the corruption to concentrated evaporation equipment 62, adjustment solution pH value is greater than 8, then gets into 2# pressure filter 59 solid-liquid separation through 2# sludge pump 58, and filtrating gets into filtrating collecting vat 60, and the solid-state thing in filtrating collecting vat 60 is collected and is sent to 2# sludge collecting vat 66 and continue the processing. And the filtrate in the filtrate collecting tank 60 enters a concentration and evaporation device 62 through an eighteenth lifting pump 61, the evaporated concentrated solution enters a concentration and crystallization device 65 through a concentrated solution collecting tank 63 and a nineteenth lifting pump 64 for further concentration treatment, and the concentrated solid enters a # 2 sludge collecting tank 66. In order to reduce the water content of solid waste, the solid waste such as sludge in the No. 2 sludge collecting tank 66 is conveyed into a sludge drying device 68 through a twentieth lift pump 67 to be further dried and dehydrated, and finally the produced sludge (solid dangerous waste) with the water content of about 9-14% is subjected to outsourcing treatment. And the distillate generated by the concentration evaporation equipment 62, the concentration crystallization equipment 65 and the sludge drying equipment 68 is uniformly collected and then returned to the wastewater collection tank 55 of the air flotation separation system through a lift pump for circular treatment.

The electroplating wastewater zero-discharge treatment system provided by the embodiment comprises a nickel and chromium-containing heavy metal wastewater pretreatment system, a membrane separation system, a purification and sterilization system and an evaporation concentration and drying system, wherein a three-level RO (reverse osmosis) system, an MVR (mechanical vapor compression) vacuum concentration and evaporation device, an MVR vacuum crystallization device and a sludge drying device 68 are combined in a multi-cycle manner, so that the wastewater is recycled to the maximum extent, and the cost of evaporation treatment per ton of water is reduced to be below 60 yuan due to the introduction of the high-efficiency low-energy-consumption MVR vacuum concentration and evaporation device and the MVR vacuum crystallization device; an EDI membrane stack and UV sterilization equipment are introduced, so that the quality of produced water is further stabilized, and the water is ensured to be recycled for a long time without breeding bacterial microorganisms and going bad; the concentration and crystallization equipment 65 and the sludge drying equipment 68 can control the water content of the sludge to be below 15 percent, liquid hazardous waste is not generated, the conductivity of the produced water of the system is less than 20us/cm, the quality of the produced water is high, the treatment cost is low (the comprehensive cost of wastewater treatment can be controlled to be 30-50 yuan/ton), and the sludge production and the hazardous waste treatment cost are greatly reduced. After the electroplating wastewater zero-discharge treatment system disclosed by the invention is used for treating the electroplating wastewater, the quality of produced reuse water is less than 20us/cm, the water reuse rate reaches more than 99.7%, and the electroplating wastewater is not deteriorated after being recycled for a long time. The system comprises a high-COD high-TDS (soluble total solids) wastewater concentration separation technology, a high-reuse-rate membrane separation and EDI (electrodialysis and ion exchange multi-element membrane stack 52), a UV (ultraviolet) combination technology and a high-efficiency drying concentration crystallization technology, more than 99.7% of treated wastewater is reused in an electroplating line, the conductivity of produced water is less than 10us/cm, and resource saving and zero discharge of electroplating wastewater are realized.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.