Nickel-containing wastewater treatment system

Abstract

The nickel-containing wastewater treatment system comprises a wastewater collection pool, the outlet end of the wastewater collection pool is connected with a Fenton reaction pool, and the outlet end of the Fenton reaction pool is sequentially connected with a reaction pool and a coagulation pool in the flowing direction of wastewater; the outlet end of the coagulating basin is connected with a flocculation basin, the outlet end of the flocculation basin is connected with a sedimentation basin, a water outlet of the sedimentation basin is connected with a sand filter, and the outlet end of the sand filter is connected with an ion exchanger for adsorbing residual nickel ions; according to the invention, ferrous sulfate and hydrogen peroxide are taken as Fenton reagents, hydroxyl free radicals with strong oxidizing property can be generated under an acidic condition, and complexed nickel is converted into free nickel; then capturing free nickel in water through a flocculating agent and generating large particles to flocculate and settle in a settling pond; and finally, trace nickel ions are separated through a sand filter and an ion exchanger, so that free nickel ions in the wastewater are reduced as much as possible, the sewage treatment quality is improved, and especially the treatment effect on the high-concentration nickel-containing wastewater is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of environmental protection equipment, in particular to a nickel-containing wastewater treatment system. BACKGROUND

[0002] PCB (Printed Circuit Board) refers to a printed circuit board, and during the product manufacturing process of the PCB industry, nickel-containing wastewater is generated. The nickel-containing wastewater of the PCB is mainly derived from gold-plated wires, and the main pollutant is chemical complex nickel. With the progress of society and the rapid development of science and technology, the electroplating industry has been rapidly promoted. As a new type of metal surface treatment technology, chemical nickel plating is increasingly concerned by people due to its simple process, energy saving and environmental protection. However, the production process of chemical nickel plating produces nickel-containing wastewater.

[0003] The nickel-containing wastewater treatment device in the prior art can only treat low-concentration nickel-containing wastewater, and when treating high-concentration nickel-containing wastewater, the discharged wastewater is difficult to meet the discharge standard. CONTENT OF THE UTILITY MODEL

[0004] The main purpose of the application is to provide a nickel-containing wastewater treatment system, which aims to solve the defect that the prior art cannot treat high-concentration nickel-containing wastewater.

[0005] The application achieves the above-mentioned purpose through the following technical scheme:

[0006] A nickel-containing wastewater treatment system comprises a wastewater collection tank.

[0007] A Fenton reaction tank, the inlet end of the Fenton reaction tank is communicated with the wastewater collection tank; along the flow direction of the wastewater, the outlet end of the Fenton reaction tank is sequentially connected with a reaction tank and a coagulation tank.

[0008] A flocculation tank, the inlet end of the flocculation tank is communicated with the outlet end of the coagulation tank; the outlet end of the flocculation tank is connected with a sedimentation tank.

[0009] A sand filter, the inlet end of the sand filter is communicated with the drain port of the sedimentation tank; the outlet end of the sand filter is further connected with an ion exchanger for adsorbing residual nickel ions.

[0010] Optionally, the wastewater treatment system further comprises a controller, the controller comprises an industrial computer and a PLC which are connected in communication.

[0011] Optionally, a pH adjusting tank is further arranged between the wastewater collection tank and the Fenton reaction tank; a stirrer and a pH control system are arranged in the pH adjusting tank, and the stirrer and the pH control system are electrically connected with the PLC respectively.

[0012] Optionally, a degassing tank is arranged between the Fenton reaction tank and the reaction tank, and an aeration stirring device is arranged in the Fenton reaction tank and the degassing tank, and the two aeration stirring devices are electrically connected with the PLC respectively; a pH control system electrically connected with the PLC is further arranged in the degassing tank.

[0013] Optionally, a stirring machine is arranged in each of the reaction tank, the coagulation tank and the flocculation tank, and each stirring machine is electrically connected with the PLC respectively.

[0014] Optionally, the wastewater treatment system further comprises a sludge tank, a sludge pipe is further arranged at the bottom of the sedimentation tank, the sludge pipe is connected with an inlet end of the sludge tank, a dewatering device for converting sludge into sludge cake is further connected with an outlet end of the sludge tank, and the dewatering device is communicated with the wastewater collecting tank through a drain pipe.

[0015] Optionally, the wastewater treatment system further comprises a neutralization tank, an outlet of the sedimentation tank is connected with an inlet end of the neutralization tank, and an intermediate water tank is connected with an outlet end of the neutralization tank, and the intermediate water tank is communicated with the sand filter.

[0016] Optionally, a stirring machine and a pH control system are arranged in the neutralization tank, and the stirring machine and the pH control system are electrically connected with the PLC respectively.

[0017] Optionally, the wastewater treatment system further comprises a discharge detection tank connected with the ion exchanger, and a water quality detection device is arranged in the discharge detection tank; a drain pipe and a backflow pipe are arranged on the discharge detection tank, an accident tank is further arranged at an outlet end of the backflow pipe, and the accident tank is communicated with the wastewater collecting tank.

[0018] Optionally, a discharge valve is arranged on the drain pipe, a backflow valve is arranged on the backflow pipe, and the discharge valve and the backflow valve are electrically connected with the PLC respectively; and the water quality detection device is electrically connected with the PLC.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The present application comprises a wastewater collecting tank, an outlet end of the wastewater collecting tank is connected with a Fenton reaction tank, an outlet end of the Fenton reaction tank is sequentially connected with a reaction tank and a coagulation tank along the flow direction of wastewater; an outlet end of the coagulation tank is connected with a flocculation tank, an outlet end of the flocculation tank is connected with a sedimentation tank, a drain port of the sedimentation tank is connected with a sand filter, and an outlet end of the sand filter is connected with an ion exchanger for adsorbing residual nickel ions;

[0021] In use, the nickel-containing wastewater is collected and buffered by the wastewater collection tank, and in the Fenton reaction tank, ferrous sulfate and hydrogen peroxide are added as Fenton reagent, which can generate strong oxidizing hydroxyl radicals under acidic conditions to convert complex nickel into free nickel; high-efficiency metal heavy trapping agent, PAC and PAM and other flocculants are added in the reaction tank, coagulation tank and flocculation tank to capture free nickel in water and generate large particle flocculation in the sedimentation tank; then the sand filter is used to remove small particles of suspended matter in the supernatant of the sedimentation tank; finally, the resin adsorption process is used as a check to remove the residual trace nickel ions in the water.

[0022] Compared with the prior art, the present application converts, adsorbs, flocculates and removes suspended solids and free nickel of different particle sizes through multiple processes, thereby reducing free nickel ions in wastewater as much as possible, improving wastewater treatment quality, and especially improving the treatment effect of high-concentration nickel-containing wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A structural schematic diagram of a nickel-containing wastewater treatment system provided for Embodiment 1 of the present application;

[0024] Figure 2 A side view of the Fenton reaction tank;

[0025] Figure 3 A top view of the Fenton reaction tank;

[0026] The drawings show that: 1 is a wastewater collection tank, 2 is a Fenton reaction tank, 3 is a reaction tank, 4 is a coagulation tank, 5 is a flocculation tank, 6 is a sedimentation tank, 7 is a sand filter, 8 is an ion exchanger, 9 is a controller, 10 is a pH adjustment tank, 11 is a stirrer, 12 is a pH control system, 13 is a degassing tank, 14 is an aeration stirring device, 15 is a sludge tank, 16 is a sludge pipe, 17 is a dewatering device, 18 is a neutralization tank, 19 is an intermediate water tank, 20 is a discharge detection tank, 21 is a water quality detection device, 22 is a drain pipe, 23 is a backflow pipe, 24 is an emergency tank, 25 is a discharge valve, 26 is a backflow valve, 301 is a partition, 302 is a first chamber, 303 is a second chamber, 304 is a connecting pipe, 305 is a water outlet weir.

[0027] The purpose of the present application, functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0028] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort are within the protection scope of the present application.

[0029] It should be noted that all the direction indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the direction indications also change accordingly.

[0030] In the present application, unless otherwise explicitly specified and limited, the terms “connection”, “fixation”, etc. should be understood in a broad sense, for example, “fixation” can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements, or interaction relationship between two elements, unless otherwise explicitly limited. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] In addition, if the present application has descriptions involving “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features, or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include at least one of the features. In addition, the meaning of “and / or” appearing throughout the text includes three parallel solutions. For example, “robot coordinate system and / or m” includes the robot coordinate system solution, or the m solution, or the solution that both the robot coordinate system and m are satisfied. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application.

[0032] Embodiment 1

[0033] Reference Figure 1The embodiment is an optional embodiment of the application, which discloses a nickel-containing wastewater treatment system, comprising a wastewater collecting pool 1, a Fenton reaction pool 2 and a controller 9, wherein a pH adjusting pool 10 is further arranged between the wastewater collecting pool 1 and the Fenton reaction pool 2, that is, the outlet end of the wastewater collecting pool 1 is connected with the inlet end of the pH adjusting pool 10, and the outlet end of the pH adjusting pool 10 is connected with the inlet end of the Fenton reaction pool 3;

[0034] The controller 9 comprises an industrial computer and a PLC, and the industrial computer is electrically connected with the PLC;

[0035] In the flow direction of the wastewater, the outlet end of the Fenton reaction pool 2 is sequentially connected with a reaction pool 3, a coagulation pool 4, a flocculation pool 5 and a sedimentation pool 6;

[0036] The pH adjusting pool 10 is provided with a stirrer 11 and a pH control system 12, and is further provided with a dosing pump, which adds acid liquid to the pH adjusting pool 10, so as to adjust the solution to be acidic and prepare for the subsequent Fenton reaction; the pH adjusting pool 10 is further provided with the stirrer 11, which can more quickly mix the acid liquid and the wastewater, improve the working efficiency and improve the detection accuracy;

[0037] The stirrer 11, the pH control system 12 and the dosing pump are electrically connected with the PLC respectively, so as to realize the automatic control of the equipment through the PLC;

[0038] While the acid liquid is added, the pH control system 12 detects the pH value in the real-time detection pool, which improves the accuracy of the pH value control and reduces the use amount of the liquid medicine, and realizes the automation of the equipment operation and improves the operation efficiency.

[0039] The Fenton reaction pool 2 is provided with a partition plate 301, which divides the Fenton reaction pool into a first chamber 302 and a second chamber 303 which are independent of each other, wherein the first chamber 302 is provided with a dosing device for adding Fenton reagent, and the second chamber 303 is provided with an aeration stirring device 14, which comprises a gas pipe, the inlet end of the gas pipe is connected with an external gas source, the outlet end of the gas pipe is inserted into the bottom of the Fenton reaction pool, and a connecting pipe 304 is further arranged in the radial direction of the gas pipe, the inlet end of the connecting pipe 304 is communicated with the first chamber 302, so as to guide the wastewater to enter into the second chamber 303 after passing through the gas pipe;

[0040] A water outlet weir 305 is further arranged on the top of the second chamber, and a water outlet pipe is arranged on the water outlet weir 305;

[0041] The ferrous sulfate and hydrogen peroxide are added as Fenton reagent in the Fenton reaction tank 2, and the wastewater is adjusted to be acidic in the pH adjusting tank 10, so that the Fenton reagent is added to the acidic wastewater, and the Fenton reagent can generate strong oxidizing hydroxyl radicals in the acidic environment, so that the complex nickel is converted into free nickel, thereby converting the difficult-to-treat complex nickel into the easy-to-treat free nickel, and improving the treatment quality of nickel;

[0042] The stirring machines 11 are arranged in the reaction tank 3, the coagulation tank 4, the flocculation tank 5 and the sedimentation tank 6, and each stirring machine 11 is electrically connected with the PLC, so that the automatic control of each device is realized through the PLC, and the rotating speed and stirring time of the stirring machine 11 are adjusted;

[0043] The metal heavy agent is added in the reaction tank 3, the PAC is added in the coagulation tank 4, and the PAM is added in the flocculation tank 5, so that the free nickel in the water is captured and large particle flocculation is generated through the use of the above-mentioned three flocculants, thereby reducing the free nickel in the wastewater as much as possible;

[0044] Further, the degassing tank 13 is arranged between the Fenton reaction tank 2 and the reaction tank 3, the aeration stirring device 14 is arranged in the degassing tank 13, and the pH control system 12 is arranged in the degassing tank 13, and the pH control system 12 is electrically connected with the PLC;

[0045] In the degassing tank 13, the liquid alkali is added to adjust the pH of the wastewater to be alkaline, and the residual hydrogen peroxide in the water is removed, so that the decomposition of the hydrogen peroxide to cause the floating sludge in the sedimentation tank 6 is avoided, thereby improving the sedimentation quality;

[0046] The outlet end of the flocculation tank 5 is further connected with the sedimentation tank 6, the sludge pipe 16 is arranged at the bottom of the sedimentation tank 6, the outlet end of the sludge pipe 16 is connected with the sludge tank 15, the outlet end of the sludge tank 15 is further connected with the dewatering device 17, and the water outlet of the dewatering device 17 is communicated with the wastewater collecting tank 1 through the drain pipe 22;

[0047] The upper portion of the sedimentation tank 6 is further provided with a water outlet for discharging the supernatant in the upper portion of the sedimentation tank 6, the water outlet is connected with the neutralization tank 18, the outlet end of the neutralization tank 18 is connected with the intermediate water tank 19, and the outlet end of the intermediate water tank 19 is sequentially connected with the sand filter 7 and the ion exchanger 8;

[0048] The stirring machine 11 and the pH control system 12 are further arranged in the neutralization tank 18, and the stirring machine 11 and the pH control system 12 are electrically connected with the PLC, respectively, and the sand filter 7 and the ion exchanger 8 are electrically connected with the PLC, respectively;

[0049] In the normal working process, the large particles of flocculation will gradually deposit in the bottom of the sedimentation tank 6, and the supernatant enters the neutralization tank 18 through the drain port. The sediment at the bottom of the sedimentation tank 6 is discharged into the sludge tank 15 through the sludge pipe 16 every interval, and the gravity concentration method is used to preliminarily concentrate the nickel-containing sludge. The sludge tank 15 is provided with a sludge delivery pump to lift the concentrated sludge-water mixture to the sludge dewatering device 17. The sludge dewatering device 17 uses a diaphragm filter press, which can effectively reduce the water content of the sludge through slurry dewatering and secondary squeezing to generate sludge cakes, thereby reducing the sludge treatment amount and converting the difficult-to-treat sludge-water mixture into easy-to-treat solid sludge. The filtrate generated by the sludge dewatering device 17 enters the wastewater collection tank 1 through the filtrate return pipe 23, ensuring that all nickel-containing wastewater is effectively treated and discharged in accordance with the standard;

[0050] In the neutralization tank 18, the supernatant is added with sulfuric acid to adjust the pH of the wastewater to be acidic, and then enters the intermediate tank 19 for temporary storage. The intermediate tank 19 serves as a buffer to adjust the water flow, thereby ensuring the stable operation of the system;

[0051] The water in the intermediate tank 19 is lifted to the sand filter 7 by a delivery pump. Through medium filtration, small particles of suspended matter in the front-end effluent are removed, and the sand filter 7 effluent is obtained. The sand filter 7 effluent enters the ion exchanger 8, which uses resin adsorption technology to remove residual trace nickel ions in the incoming water, and finally obtains fully purified and stable effluent that meets the standard;

[0052] The ion exchanger 8 is filled with polystyrene macroporous, iminodiacetic acid integrated resin, which has strong running capacity, excellent permeation stability, can effectively adsorb nickel ions in water, and has excellent nickel removal effect. The PLC controller 9 sets the water production, backwashing, regeneration, flushing, and transformation time to realize automatic operation and automatic maintenance cleaning. The running parameters of each stage can be changed according to the water quality of the inlet and outlet to ensure that the system adapts to changes in different water qualities. An observation window is provided on the ion exchanger 8, through which the color and color change of the resin at the key height position in the tank body can be observed to determine the effectiveness of the resin.

[0053] Further, the outlet end of the ion exchanger 8 is also provided with a discharge detection tank 20, and the discharge detection tank 20 is provided with a water quality detection device 21. A drain pipe 22 and a return pipe 23 are provided on the discharge detection tank 20, and the outlet end of the return pipe 23 is also provided with an accident tank 24. The accident tank 24 is communicated with the wastewater collection tank 1 through a water delivery pipe and a delivery pump;

[0054] The drain pipe 22 is provided with a discharge valve 25, and the backflow pipe 23 is provided with a backflow valve 26, and the discharge valve 25 and the backflow valve 26 are respectively electrically connected with the PLC; the water quality detection device 21 is electrically connected with the PLC;

[0055] After the treated wastewater enters the discharge detection tank 20, the water quality is detected by the water quality detection device 21, if the detection is qualified, the discharge valve 25 is opened, and the treated wastewater is discharged; if the detection is unqualified, the discharge valve 25 is closed, the backflow valve 26 is opened, the treated water is introduced into the emergency tank 24 for re-treatment and then recycled to the wastewater collection tank 1 for re-treatment, so as to ensure that the nickel content of the effluent meets the standard.

[0056] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A nickel-containing wastewater treatment system, characterized in that, Including wastewater collection pond (1); Fenton reactor (2), the inlet end of which is connected to the wastewater collection tank (1); along the flow direction of the wastewater, the outlet end of the Fenton reactor is connected to the reaction tank (3) and the coagulation tank (4) in sequence. A flocculation tank (5) is connected to the outlet of the coagulation tank (4) at its inlet end; a sedimentation tank (6) is connected to the outlet of the flocculation tank (5). A sand filter (7) is provided, the inlet end of which is connected to the outlet of the sedimentation tank (6); the outlet end of the sand filter (7) is also connected to an ion exchanger (8) for adsorbing residual nickel ions.

2. The nickel-containing wastewater treatment system according to claim 1, characterized in that, The wastewater treatment system also includes a controller (9), which includes an industrial control computer and a PLC connected in communication.

3. The nickel-containing wastewater treatment system according to claim 2, characterized in that, A pH adjustment tank (10) is also provided between the wastewater collection tank (1) and the Fenton reaction tank (2); a stirrer (11) and a pH control system (12) are provided in the pH adjustment tank (10), and the stirrer (11) and the pH control system (12) are electrically connected to the PLC respectively.

4. The nickel-containing wastewater treatment system according to claim 3, characterized in that, A degassing tank (13) is also provided between the Fenton reaction tank (2) and the reaction tank (3). Both the Fenton reaction tank (2) and the degassing tank (13) are equipped with an aeration and stirring device (14), and the two aeration and stirring devices (14) are electrically connected to the PLC respectively. A pH control system (12) electrically connected to the PLC is also provided in the degassing tank (13).

5. The nickel-containing wastewater treatment system according to claim 3, characterized in that, Each of the reaction tank (3), coagulation tank (4) and flocculation tank (5) is equipped with a mixer (11), and each mixer (11) is electrically connected to the PLC.

6. The nickel-containing wastewater treatment system according to claim 1, characterized in that, The wastewater treatment system also includes a sludge tank (15), and a sludge pipe (16) is provided at the bottom of the sedimentation tank (6). The sludge pipe (16) is connected to the inlet end of the sludge tank (15). The outlet end of the sludge tank (15) is also connected to a dewatering device (17) for converting sludge into sludge cake. The dewatering device (17) is connected to the wastewater collection tank (1) through a drain pipe (22).

7. The nickel-containing wastewater treatment system according to claim 3, characterized in that, The wastewater treatment system also includes a neutralization tank (18), the inlet of which is connected to the outlet of the sedimentation tank (6), the outlet of which is connected to an intermediate water tank (19), and the outlet of which is connected to the sand filter (7).

8. The nickel-containing wastewater treatment system according to claim 7, characterized in that, The neutralization tank (18) is equipped with a stirrer (11) and a pH control system (12), and the stirrer (11) and the pH control system (12) are electrically connected to the PLC respectively.

9. A nickel-containing wastewater treatment system according to claim 3, characterized in that, The wastewater treatment system also includes a discharge detection pool (20) connected to the ion exchanger (8), and a water quality detection device (21) is installed in the discharge detection pool (20); a drain pipe (22) and a return pipe (23) are installed on the discharge detection pool (20), and an emergency pool (24) is also installed at the outlet end of the return pipe (23), and the emergency pool (24) is connected to the wastewater collection pool (1).

10. A nickel-containing wastewater treatment system according to claim 9, characterized in that, The drain pipe (22) is equipped with a discharge valve (25), and the return pipe (23) is equipped with a return valve (26). The discharge valve (25) and the return valve (26) are respectively electrically connected to the PLC; the water quality detection device (21) is electrically connected to the PLC.

Images