Zinc-nickel-chromium waste liquid treatment system and treatment method thereof

Abstract

The invention provides a zinc-nickel-chromium waste liquid treatment system and a treatment method thereof.The zinc-nickel-chromium waste liquid treatment system comprises two independent treatment mechanisms, and each treatment mechanism comprises a wastewater collecting tank, a wastewater reaction tank and a multi-stage sedimentation tank which are sequentially communicated through a pipeline according to the treatment sequence; the liquid treatment assembly and the sludge treatment assembly are respectively communicated with the multi-stage sedimentation tank through pipelines, the liquid treatment assembly comprises a filter and a resin tank which are sequentially communicated through pipelines, and the sludge treatment assembly comprises a sludge tank and a filter press connected to the sludge tank. The tail end of the liquid treatment assembly and the tail end of the sludge treatment assembly are respectively communicated with the wastewater collecting tank, so that the treatment mechanism forms a circulating pipeline, the wastewater collecting tank is communicated with the wastewater reaction tank through a lifting pump, the sludge tank is communicated with the filter press through a pneumatic diaphragm pump, and the sludge tank is communicated with the filter press through a pneumatic diaphragm pump. The effect of treating the waste liquid containing zinc, nickel and chromium heavy metal ions is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of waste liquid treatment, and specifically relates to a zinc-nickel-chromium waste liquid treatment system and a treatment method thereof. Background Art

[0002] Under the background of the rapid development of the current electronic information industry, the market demand for lithium battery copper foil continues to grow, and customers' quality requirements for lithium battery copper foil are becoming increasingly stringent. Since copper foil itself is easily oxidized and has relatively poor physical and chemical properties, specific additives must be added to the electrolyte during the production process of electrolytic copper foil to enhance the physical and chemical properties of copper foil. In addition, the surface of copper foil needs to be treated with anti-oxidation treatment, which can not only enhance the antioxidant capacity of copper foil, but also prolong its storage time, thereby improving the overall performance of copper foil.

[0003] These additives and anti-oxidation liquids usually contain heavy metal ions such as zinc, nickel, and chromium. From an environmental protection perspective, this means that waste liquids containing heavy metals must be treated before they can be discharged. Therefore, how to treat waste liquids containing zinc, nickel, and chromium has become a problem to be solved. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a zinc-nickel-chromium waste liquid treatment system and a treatment method thereof, which are used to solve the technical problems of the above background technology.

[0005] On the one hand, the invention provides the following technical solutions: a zinc-nickel-chromium waste liquid treatment system, comprising two independent treatment mechanisms, wherein the treatment mechanism comprises a wastewater collection tank, a wastewater reaction tank, and a multi-stage sedimentation tank connected by pipelines in sequence in a treatment order, and a liquid treatment component and a sludge treatment component connected to the multi-stage sedimentation tank by pipelines, respectively; the liquid treatment component comprises a filter and a resin tank connected by pipelines in sequence, the sludge treatment component comprises a sludge tank and a filter press connected to the sludge tank, the end of the liquid treatment component and the end of the sludge treatment component are respectively connected to the wastewater collection tank, so that the treatment mechanism forms a circulation pipeline, wherein the wastewater collection tank is connected to the wastewater reaction tank through a lifting pump, and the sludge tank is connected to the filter press through a pneumatic diaphragm pump.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: first, according to the metal types contained in the waste liquid, if the waste liquid contains zinc and nickel, the zinc and nickel waste liquid is discharged into the wastewater collection tank of the first treatment mechanism; if the waste liquid contains chromium, the chromium waste liquid is discharged into the wastewater collection tank of the second treatment mechanism; and then the waste liquid is transported to the wastewater reaction tank via a delivery pump; the wastewater reaction tank contains an oxidant, an alkali agent, and a precipitant; the waste liquid is stirred and reacted in the reaction tank, and then sent to a multi-stage sedimentation tank for precipitation; after the reaction in the sedimentation tank, most of the zinc, nickel, and chromium ions form sludge, which is transported to the sludge tank; the waste liquid treated with precipitation is transported by a resin pump through a filter and a resin tank, and then transported to a zinc buffer tank; the waste liquid that is qualified in zinc, nickel, and chromium is discharged to the external drainage tank, and the unqualified waste liquid is continuously sent back to the wastewater collection tank. The sludge in the sludge pool is transported to the filter press through a pneumatic diaphragm pump to quickly dry the sludge into dry mud. The formed dry mud is transported out for treatment, and the zinc, nickel and chromium waste liquid filtered out is continuously sent back to the wastewater collection tank. The entire system is a circulation system. After the waste liquid is repeatedly filtered, the zinc, nickel and chromium heavy metal ions in the waste liquid are treated and separated, thereby achieving the effect of purifying the waste liquid. It can be seen that through the work of two independent treatment mechanisms, the zinc and nickel waste liquid and the chromium waste liquid are treated respectively, achieving the effect of treating the waste liquid containing zinc, nickel and chromium heavy metal ions.

[0007] Furthermore, the filter comprises a plurality of hollow cylinders connected in series, and adsorbent is arranged in the hollow cylinders.

[0008] Furthermore, the multi-stage sedimentation tank of one of the treatment mechanisms includes a primary sedimentation tank, a primary reaction tank, a zinc-nickel secondary sedimentation tank and a zinc-nickel secondary reaction tank which are connected by pipelines in sequence according to the treatment order. The primary sedimentation tank and the zinc-nickel secondary sedimentation tank each include two filtration spaces, and a mud discharge valve is provided at the bottom of the filtration space. Alkali agent and aeration are respectively provided in the primary reaction tank and the zinc-nickel secondary reaction tank.

[0009] Furthermore, the multi-stage sedimentation tank of the second treatment mechanism includes a chromium secondary sedimentation tank, a chromium secondary reaction tank, a chromium inclined plate sedimentation tank, a first biochemical tank, a second biochemical tank, a tertiary sedimentation tank, a tertiary reaction tank and a fourth sedimentation tank which are connected by pipelines in sequence according to the treatment order. The chromium secondary reaction tank is provided with a heavy capture agent, polyaluminum chloride and inorganic polymer water treatment agents, the first biochemical tank and the second biochemical tank are respectively provided with aeration, the tertiary sedimentation tank and the fourth sedimentation tank are respectively provided with scrapers, and the chromium inclined plate sedimentation tank is connected to the first biochemical tank through a chromium biochemical tank lifting pump.

[0010] Furthermore, the second treatment mechanism includes a chromium plating solution tank, which is connected to the wastewater collection tank of the second treatment mechanism through a chromium plating solution pump.

[0011] Furthermore, the wastewater reaction tank includes a tank body and a plurality of partitions arranged in the tank body, wherein the three partitions divide the tank body into a plurality of reaction cavities, the plurality of reaction cavities are connected in series, a stirring mechanism is arranged in each of the reaction cavities, and reactants are respectively arranged in the plurality of reaction cavities.

[0012] Furthermore, the reactants in the multiple reaction cavities of one of the treatment mechanisms are respectively an oxidant, an alkali agent, polyaluminium chloride and an inorganic polymer water treatment agent;

[0013] Secondly, the reactants in the multiple reaction cavities of the treatment mechanism are respectively acid, reducing agent, alkali agent, polyaluminium chloride and inorganic polymer water treatment agent.

[0014] Furthermore, the buffer pools of the two processing mechanisms are the same.

[0015] Furthermore, the treatment mechanism also includes a buffer tank, and an online metal monitor is provided on the buffer tank to monitor the heavy metal content in the liquid of the buffer tank, and the heavy metal content is discharged to an external drainage tank after reaching the discharge standard.

[0016] On the other hand, the present invention also provides a treatment method for a zinc-nickel-chromium waste liquid treatment system, the treatment method comprising the following steps:

[0017] Determine the type of wastewater on the electroplating production line, select one of the two treatment mechanisms based on the type of wastewater, and collect the wastewater into the wastewater collection tank of the selected one of the treatment mechanisms;

[0018] The wastewater in the wastewater collection tank is sent to the wastewater reaction tank, and a reactant is added to the wastewater reaction tank for stirring reaction to generate large particles insoluble in water;

[0019] Large-particle flocculants are sent to multi-stage sedimentation tanks for sedimentation to form sludge and waste liquid;

[0020] The sludge is sent to a sludge pool to be concentrated, and the concentrated sludge is dehydrated by a box filter press to form dehydrated sludge;

[0021] The waste liquid is transported through a resin pump, filtered through a filter and a resin tank, and then transported to a buffer tank. The waste liquid that passes the inspection is discharged from the buffer tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the zinc-nickel-chromium waste liquid treatment system in the zinc-nickel embodiment of the present invention.

[0023] Figure 2 The figure is a schematic diagram of the process flow of a processing mechanism of one embodiment of zinc-nickel of the present invention.

[0024] Figure 3 It is a schematic diagram of the process flow of the second processing mechanism of the zinc-nickel embodiment of the present invention.

[0025] Figure 4 It is a schematic diagram of the structure of the zinc-nickel embodiment filter of the present invention.

[0027] Main component symbol description: 100, treatment mechanism; 10, wastewater collection tank; 11, lifting pump; 20, wastewater reaction tank; 21, reaction cavity; 22, stirring mechanism; 30, multi-stage sedimentation tank; 311, primary sedimentation tank; 312, primary reaction tank; 313, zinc-nickel secondary sedimentation tank; 314, zinc-nickel secondary reaction tank; 321, chromium secondary sedimentation tank; 322, chromium secondary reaction tank; 323, chromium inclined plate sedimentation tank; 32 4. First biochemical pool; 325. Second biochemical pool; 326. Third-stage sedimentation pool; 327. Third-stage reaction pool; 328. Fourth-stage sedimentation pool; 329. Sludge scraper; 33. Chrome plating pool; 40. Liquid treatment component; 41. Filter; 411. Hollow cylinder; 412. Adsorbent; 42. Resin tank; 43. Buffer pool; 50. Sludge treatment component; 51. Sludge pool; 52. Filter press; 53. Pneumatic diaphragm pump.

[0028] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] Embodiment 1

[0033] See also Figure 1 As shown, the zinc-nickel-chromium waste liquid treatment system in the first embodiment of the present invention includes two independent treatment mechanisms 100, the treatment mechanism 100 includes a wastewater collection tank 10, a wastewater reaction tank 20, and a multi-stage sedimentation tank 30 which are sequentially connected by pipelines in the treatment order, and a liquid treatment component 40 and a sludge treatment component 50 which are respectively connected to the multi-stage sedimentation tank 30 by pipelines, the liquid treatment component 40 includes a filter 41, a resin tank 42 and a buffer tank 43 which are sequentially connected by pipelines, the sludge treatment component 50 includes a sludge tank 51 and a filter press 52 connected to the sludge tank 51, the end of the liquid treatment component 40 and the end of the sludge treatment component 50 are respectively connected to the wastewater collection tank 10, so that the treatment mechanism 100 forms a circulation pipeline, wherein the wastewater collection tank 10 is connected to the wastewater reaction tank 20 through a lifting pump 11, and the sludge tank 51 is connected to the filter press 52 through a pneumatic diaphragm pump 53.

[0034] In this embodiment, two independent treatment mechanisms 100 are used to treat the zinc-nickel waste liquid and the chromium waste liquid respectively.

[0035] First, according to the type of metal contained in the waste liquid, if the waste liquid contains zinc and nickel, the zinc and nickel waste liquid is discharged into the wastewater collection tank 10 of the first treatment mechanism 100; if the waste liquid contains chromium, the chromium waste liquid is discharged into the wastewater collection tank 10 of the second treatment mechanism 100; and then the waste liquid is transported to the wastewater reaction tank 20 via a delivery pump. The wastewater reaction tank 20 contains an oxidant, an alkali agent, and a precipitant. The waste liquid is stirred and reacted in the reaction tank, and then sent to a multi-stage sedimentation tank 30 for precipitation. After the reaction in the sedimentation tank, most of the zinc, nickel, and chromium ions form sludge, which is transported to the sludge tank 51. The waste liquid after precipitation treatment is transported by a resin pump through a filter 41 and a resin tank 42 for filtration, and then transported to a zinc buffer tank 43. The waste liquid that is qualified in zinc, nickel, and chromium can be discharged to the external drainage tank, and the unqualified waste liquid is continuously sent back to the wastewater collection tank 10. The sludge in the sludge pool 51 is transported to the filter press 52 by the pneumatic diaphragm pump 53 so that the sludge is quickly dried into dry mud. The formed dry mud is transported out for treatment, and the zinc, nickel and chromium waste liquid filtered out is continuously sent back to the wastewater collection tank 10. The whole system is a circulation system. After the waste liquid is repeatedly filtered, the zinc, nickel and chromium heavy metal ions in the waste liquid are processed and separated, thereby achieving an effect of purifying the waste liquid. It can be seen that through the work of two independent processing mechanisms 100, the zinc and nickel waste liquid and the chromium waste liquid are processed respectively, so as to achieve the effect of processing the waste liquid containing zinc, nickel and chromium heavy metal ions.

[0036] See also Figure 2As shown, specifically, the multi-stage sedimentation tank 30 of one of the treatment mechanisms 100 includes a primary sedimentation tank 311, a primary reaction tank 312, a zinc-nickel secondary sedimentation tank 313 and a zinc-nickel secondary reaction tank 314 which are sequentially connected by pipelines in a treatment order, the primary sedimentation tank 311 and the zinc-nickel secondary sedimentation tank 313 each include two filtration spaces, a mud discharge valve is provided at the bottom of the filtration space, and an alkali agent and aeration are respectively provided in the primary reaction tank 312 and the zinc-nickel secondary reaction tank 314.

[0037] See also Figure 3 As shown, specifically, the multi-stage sedimentation tank 30 of the second treatment mechanism 100 includes a chromium secondary sedimentation tank 321, a chromium secondary reaction tank 322, a chromium inclined plate sedimentation tank 323, a first biochemical tank 324, a second biochemical tank 325, a tertiary sedimentation tank 326, a tertiary reaction tank 327 and a quaternary sedimentation tank 328, which are connected by pipelines in sequence according to the treatment order. The chromium secondary reaction tank 322 is provided with a heavy capture agent, polyaluminum chloride and an inorganic polymer water treatment agent, the first biochemical tank 324 and the second biochemical tank 325 are respectively provided with aeration, the tertiary sedimentation tank 326 and the quaternary sedimentation tank 328 are respectively provided with a scraper 329, and the chromium inclined plate sedimentation tank 323 is connected to the first biochemical tank 324 through a chromium biochemical tank lifting pump 11.

[0038] More specifically, the second treatment mechanism 100 includes a chromium plating solution pool 33, and the chromium plating solution pool 33 is connected to the wastewater collection pool 10 of the second treatment mechanism 100 through a chromium plating solution pump.

[0039] Specifically, the wastewater reaction tank 20 includes a tank body and a plurality of partitions arranged in the tank body, wherein the three partitions divide the tank body into a plurality of reaction cavities 21, the plurality of reaction cavities 21 are connected in series, a stirring mechanism 22 is arranged in each of the reaction cavities 21, and reactants are respectively arranged in the plurality of reaction cavities 21.

[0040] More specifically, the reactants in the multiple reaction cavities 21 of the treatment mechanism 100 are oxidants, alkali agents, polyaluminium chloride and inorganic polymer water treatment agents;

[0041] Secondly, the reactants in the multiple reaction cavities 21 of the treatment mechanism 100 are respectively acid, reducing agent, alkali agent, polyaluminium chloride and inorganic polymer water treatment agent. In specific implementation, after the corresponding reactant is added into each reaction cavity 21, the stirring mechanism 22 is started to stir, so that the reactant in each reaction cavity 21 is stirred and reacted with the waste liquid.

[0042] See also Figure 4As shown, specifically, the filter 41 includes a plurality of hollow cylinders 411 connected in series, and an adsorbent 412 is disposed in the hollow cylinder 411. The adsorbent 412 may be activated carbon, porous carbon material (ordered mesoporous carbon) or nanomaterial (nano iron oxide). In this embodiment, the adsorbent 412 in each of the hollow cylinders 411 is detachable and replaceable.

[0043] Furthermore, the buffer tank 43 of the two treatment mechanisms 100 is the same, so that the waste liquid treated by the two treatment mechanisms 100 flows through the same buffer tank 43 .

[0044] Furthermore, the buffer tank 43 is provided with an online metal monitor to monitor the heavy metal content in the liquid of the buffer tank 43, and the heavy metal content is discharged to an external drainage tank when it reaches the discharge standard.

[0045] Embodiment 2

[0046] The figure shows a method for treating a zinc-nickel-chromium waste liquid treatment system in a second embodiment of the present invention, the method comprising the following steps: step S01 to step S05;

[0047] S01, determining the type of wastewater on the electroplating production line, selecting one of two treatment mechanisms based on the type of wastewater, and collecting the wastewater into a wastewater collection tank of the selected one of the treatment mechanisms;

[0048] Specifically, according to the type of metal contained in the waste liquid, if the waste liquid contains zinc and nickel, the zinc-nickel waste liquid is discharged into the wastewater collection tank of one treatment mechanism; if the waste liquid contains chromium, the chromium waste liquid is discharged into the wastewater collection tank of the second treatment mechanism.

[0049] S02, sending the wastewater in the wastewater collection tank to the wastewater reaction tank, adding a reactant into the wastewater reaction tank for stirring reaction, and generating large particles insoluble in water;

[0050] Specifically, the wastewater reaction tank contains an oxidant, an alkali agent, and a precipitant, and the waste liquid is stirred and reacted in the reaction tank to generate large particles that are insoluble in water.

[0051] S03, large-particle flocculants are sent to a multi-stage sedimentation tank for sedimentation to form sludge and waste liquid;

[0052] Specifically, it is sent to a multi-stage sedimentation tank for sedimentation. After the reaction in the multi-stage sedimentation tank, most of the zinc and nickel or chromium ions form sludge, and the sludge is transported to a sludge tank.

[0053] S04, sending the sludge to a sludge pool to concentrate the sludge, and dehydrating the concentrated sludge through a box filter press to form dehydrated sludge;

[0054] Specifically, the sludge in the sludge pool is transported to the filter press through a pneumatic diaphragm pump to quickly dry the sludge into dry sludge. The formed dry sludge is transported out for treatment, and the zinc and nickel or chromium waste liquid filtered out is continuously sent back to the wastewater collection tank.

[0055] S05, conveying the waste liquid through a resin pump, filtering through a filter and a resin tank, and then conveying it to a buffer tank, and discharging the waste liquid from the buffer tank after passing the inspection;

[0056] Specifically, the waste liquid that has been precipitated in the multi-stage sedimentation tank is transported by a resin pump through the filter and the resin tank, and then transported to the zinc-nickel-chromium buffer tank. The waste liquid that passes the zinc, nickel and chromium inspection can be discharged to the external drainage pool, and the unqualified waste liquid will be returned to the wastewater collection pool.

[0057] In summary, the zinc-nickel-chromium waste liquid treatment system and treatment method thereof in the above-mentioned embodiments of the present invention have the following advantages:

[0058] The two independent treatment mechanisms are both circulation systems with orderly treatment procedures, multi-layer treatment, multi-stage filtration, environmental protection and reliability. Only waste liquid that passes the zinc, nickel and chromium inspection can be discharged to the drainage pool, and unqualified waste liquid will be sent back for circulation treatment. The system can fully separate the zinc, nickel and chromium heavy metal ions in the waste liquid, improve the discharge standards and avoid environmental pollution.

[0059] Two independent processing mechanisms form a stable cycle, reducing unnecessary liquid replacement processes and thus reducing labor costs.

[0060] After the waste liquid is treated, the zinc, nickel and chromium separated with high purity can be recycled to improve the utilization rate of zinc, nickel and chromium in the solution and avoid waste of resources.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A zinc-nickel-chromium waste liquid treatment system, characterized in that: It comprises two independent treatment mechanisms, wherein the treatment mechanism comprises a wastewater collection tank, a wastewater reaction tank, and a multi-stage sedimentation tank which are sequentially connected by pipelines in a treatment order, and a liquid treatment component and a sludge treatment component which are respectively connected by pipelines to the multi-stage sedimentation tanks, the liquid treatment component comprises a filter and a resin tank which are sequentially connected by pipelines, the sludge treatment component comprises a sludge tank and a filter press connected to the sludge tank, the end of the liquid treatment component and the end of the sludge treatment component are respectively connected to the wastewater collection tank, so that the treatment mechanism forms a circulation pipeline, wherein the wastewater collection tank is connected to the wastewater reaction tank through a lifting pump, and the sludge tank is connected to the filter press through a pneumatic diaphragm pump.

2. The zinc-nickel-chromium waste liquid treatment system according to claim 1, characterized in that: The filter comprises a plurality of hollow cylinders connected in series, wherein adsorbents are arranged inside the hollow cylinders.

3. The zinc-nickel-chromium waste liquid treatment system according to claim 1, characterized in that: The multi-stage sedimentation tank of the treatment mechanism includes a primary sedimentation tank, a primary reaction tank, a zinc-nickel secondary sedimentation tank and a zinc-nickel secondary reaction tank which are connected by pipelines in sequence according to the treatment order. The primary sedimentation tank and the zinc-nickel secondary sedimentation tank each include two filtration spaces, and a mud discharge valve is provided at the bottom of the filtration space. Alkali agent and aeration are respectively provided in the primary reaction tank and the zinc-nickel secondary reaction tank.

4. The zinc-nickel-chromium waste liquid treatment system according to claim 1, characterized in that: Secondly, the multi-stage sedimentation tank of the treatment mechanism includes a chromium secondary sedimentation tank, a chromium secondary reaction tank, a chromium inclined plate sedimentation tank, a first biochemical tank, a second biochemical tank, a tertiary sedimentation tank, a tertiary reaction tank and a fourth sedimentation tank which are connected by pipelines in sequence according to the treatment order. The chromium secondary reaction tank is provided with a heavy capture agent, polyaluminum chloride and an inorganic polymer water treatment agent. The first biochemical tank and the second biochemical tank are respectively provided with aeration. The tertiary sedimentation tank and the fourth sedimentation tank are respectively provided with a sludge scraper. The chromium inclined plate sedimentation tank is connected to the first biochemical tank through a chromium biochemical tank lifting pump.

5. The zinc-nickel-chromium waste liquid treatment system according to claim 4, characterized in that: The second treatment mechanism includes a chromium plating solution pool, which is connected to the wastewater collection tank of the second treatment mechanism through a chromium plating solution pump.

6. The zinc-nickel-chromium waste liquid treatment system according to claim 1, characterized in that: The wastewater reaction tank comprises a tank body and a plurality of partitions arranged in the tank body, wherein three partitions divide the tank body into a plurality of reaction cavities, the plurality of reaction cavities are connected in series, a stirring mechanism is arranged in each of the reaction cavities, and reactants are respectively arranged in the plurality of reaction cavities.

7. The zinc-nickel-chromium waste liquid treatment system according to claim 6, characterized in that: The reactants in the plurality of reaction cavities of the treatment mechanism are respectively an oxidant, an alkali agent, polyaluminium chloride and an inorganic polymer water treatment agent; Secondly, the reactants in the multiple reaction cavities of the treatment mechanism are respectively acid, reducing agent, alkali agent, polyaluminium chloride and inorganic polymer water treatment agent.

8. The zinc-nickel-chromium waste liquid treatment system according to claim 1, characterized in that: The buffer pools of the two processing mechanisms are the same.

9. The zinc-nickel-chromium waste liquid treatment system according to claim 1, characterized in that: The treatment mechanism also includes a buffer tank, on which an online metal monitor is provided to monitor the heavy metal content in the liquid of the buffer tank, and the heavy metal content is discharged to an external drainage tank when the heavy metal content reaches the discharge standard.

10. A method for treating a zinc-nickel-chromium waste liquid treatment system according to claims 1 to 9, characterized in that: The method comprises the following steps: Determine the type of wastewater on the electroplating production line, select one of the two treatment mechanisms based on the type of wastewater, and collect the wastewater into the wastewater collection tank of the selected one of the treatment mechanisms; The wastewater in the wastewater collection tank is sent to the wastewater reaction tank, and a reactant is added to the wastewater reaction tank for stirring reaction to generate large particles insoluble in water; Large-particle flocculants are sent to multi-stage sedimentation tanks for sedimentation to form sludge and waste liquid; The sludge is sent to a sludge pool to be concentrated, and the concentrated sludge is dehydrated by a box filter press to form dehydrated sludge; The waste liquid is transported through a resin pump, filtered through a filter and a resin tank, and then transported to a buffer tank. The waste liquid that passes the inspection is discharged from the buffer tank.

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