Treatment system for wastewater containing COD (Chemical Oxygen Demand)

Abstract

The utility model discloses a treatment system for wastewater containing COD (Chemical Oxygen Demand). The treatment system comprises a neutralizing tank, a filter connected with an outlet of the neutralizing tank, a flocculation reactor connected with a first outlet of the filter and a centrifugal machine connected with a second outlet of the filter. In the scheme, the filter and the flocculation reactor are arranged in the COD wastewater treatment system aiming at the suspension discharged from the neutralizing tank, so that the suspension is firstly filtered by the filter, then the filtrate is flocculated by the flocculation reactor, and finally the clear liquid is discharged. Through multi-stage treatment of COD wastewater, treatment of COD wastewater with different concentrations and water qualities is realized, and the problem that low-concentration COD wastewater is difficult to effectively treat in the prior art is solved; and meanwhile, the removal rate of COD (Chemical Oxygen Demand) is also obviously improved, and the standard discharge of clear liquid is finally realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to COD containing wastewater treatment technical field, specifically related to a kind of COD containing wastewater treatment system. BACKGROUND

[0002] The process and method for treating COD-containing wastewater in wastewater mainly include electrolysis, incineration, multi-effect evaporation concentration crystallization and biological method.

[0003] Electrolysis: wastewater can be treated by electrolysis, but electrolysis is affected by water quality and other factors, and has certain concentration requirements for wastewater pollutants, so it is not suitable for wastewater with low concentration and large water quality fluctuations.

[0004] Incineration: incineration is a method of treating wastewater by incineration technology, which is suitable for treating wastewater that is difficult to volatilize and degrade, but its operation cost is high and it is not suitable for low-content wastewater, and incineration produces harmful waste gas to the environment.

[0005] Multi-effect evaporation concentration crystallization: multi-effect evaporation concentration crystallization is a chemical unit operation method, which separates water and organic matter by evaporating part of the solvent through heating. Due to the difference in wastewater quality, the effect of multi-effect evaporation concentration crystallization is different, so it is mainly used in the pretreatment stage of wastewater, and the energy consumption is high, so it is not suitable for the treatment process of low-concentration wastewater.

[0006] Biological method: it is a sequencing batch activated sludge method, which is an activated sludge wastewater treatment technology operated in intermittent aeration mode. It is operated in sequence and intermittently, and the removal rate of COD is between 32.2% and 76.2%, but for low-concentration catalyst production wastewater, the process route is long and the operation cost is high. UTILITY MODEL CONTENT

[0007] One of the technical problems to be solved by the utility model is that the existing COD wastewater treatment method cannot effectively treat low-concentration COD wastewater.

[0008] In order to achieve the above purpose, the utility model provides a COD-containing wastewater treatment system, which comprises:

[0009] A neutralization tank, a filter connected to the outlet of the neutralization tank, a flocculation reactor connected to the first outlet of the filter, and a centrifuge connected to the second outlet of the filter.

[0010] The neutralization tank is used for reaction and sedimentation of the COD-containing wastewater and a neutralizing agent to obtain a suspension and a precipitate; the filter is used for receiving and filtering the suspension from the neutralization tank to obtain a slurry and a first filtrate; the flocculation reactor is used for receiving the first filtrate from the filter and performing a flocculation reaction to obtain a clear liquid and a particulate; and the centrifuge is used for receiving and filtering the slurry from the filter to obtain a filter residue and a second filtrate.

[0011] In some embodiments, the number of filters is set to one or more.

[0012] In some embodiments, the number of filters is set to multiple, and the multiple filters are connected in parallel, and each first outlet of the filters is connected with a flocculation reactor.

[0013] In some embodiments, the system further comprises a wastewater storage tank and a first dosing device, the outlet of the wastewater storage tank is connected with the first inlet of the neutralization tank, and the outlet of the first dosing device is connected with the second inlet of the neutralization tank.

[0014] In some embodiments, the system further comprises a second dosing device, and the outlet of the second dosing device is connected with the inlet of the flocculation reactor.

[0015] In some embodiments, the system further comprises a control system, which is communicatively connected with the neutralization tank, the filter, the flocculation reactor and the centrifuge to realize automatic feeding and discharging.

[0016] In some embodiments, a suspension pipeline is connected between the outlet of the neutralization tank and the inlet of the filter, and a delivery pump is arranged on the suspension pipeline.

[0017] In some embodiments, a slurry pipeline is connected between the second outlet of the filter and the inlet of the centrifuge, and a delivery pump is arranged on the slurry pipeline.

[0018] In some embodiments, a particulate recovery pipeline is connected with the first outlet of the flocculation reactor, and a clear liquid pipeline is connected with the second outlet of the flocculation reactor.

[0019] In some embodiments, a filter residue recovery pipeline is connected with the first outlet of the centrifuge, and the second outlet of the centrifuge is connected with the third inlet of the neutralization tank.

[0020] In some embodiments, the filter is a drum filter or a belt filter.

[0021] By the technical scheme, the filter and the flocculation reactor are arranged in the COD wastewater treatment system for the suspension discharged from the neutralizing tank, so that the suspension is firstly filtered by the filter, then the filtrate is subjected to flocculation treatment by the flocculation reactor, and finally the clear liquid is discharged. Through the multi-stage treatment of the COD wastewater, the COD wastewater with different concentrations and water qualities is treated, the problem that the prior art cannot effectively treat the low-concentration COD wastewater is solved, the removal rate of the COD is significantly improved, and finally the clear liquid is discharged up to the standard. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a process flow chart of the COD wastewater treatment system.

[0023] BRIEF DESCRIPTION OF DRAWINGS

[0024] 1, wastewater storage tank; 2, first dosing device; 3, neutralizing tank; 4, filter; 5, flocculation reactor; 6, second dosing device; 7, centrifuge; 8, control system; 9, wastewater pipeline; 10, neutralizing agent pipeline; 11, suspension pipeline; 12, slurry pipeline; 13, first filtrate pipeline; 14, flocculant pipeline; 15, clear liquid pipeline; 16, particulate matter recovery pipeline; 17, filter residue recovery pipeline; 18, second filtrate pipeline; 19, delivery pump; 20, feed valve; 21, discharge valve. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0026] To solve the problem that the COD wastewater treatment method in the prior art cannot effectively treat low-concentration COD wastewater, the present application provides a COD wastewater treatment system, characterized in that it comprises: a neutralizing tank 3, a filter 4 connected with the outlet of the neutralizing tank 3, a flocculation reactor 5 connected with the first outlet of the filter 4, and a centrifuge 7 connected with the second outlet of the filter 4.

[0027] The neutralizing tank 3 is used for reaction and sedimentation of the COD wastewater and the neutralizing agent to obtain a suspension and a precipitate; the filter 4 is used for receiving and filtering the suspension from the neutralizing tank 3 to obtain a slurry and a first filtrate; the flocculation reactor 5 is used for receiving the first filtrate from the filter 4 and performing flocculation reaction to obtain a clear liquid and particulate matter; and the centrifuge 7 is used for receiving and filtering the slurry from the filter 4 to obtain filter residue and a second filtrate.

[0028] As Figure 1As shown, the neutralization tank 3 can include a tank body for sedimentation and neutralization reaction, a stirring mechanism arranged in the middle of the tank body, and a liquid level meter; the filter 4 can include a cylinder for filtering the suspension, a filter medium arranged in the cylinder, a liquid level meter, and a pressure transmitter; the flocculation reactor 5 can include a tank body for performing flocculation reaction of the first filtrate, a stirring mechanism arranged in the middle of the tank body, and a liquid level meter; and the centrifuge 7 can include a tank body for filtering the slurry, a filter medium arranged in the tank body, and a liquid level meter.

[0029] The neutralization tank 3, the filter 4, the flocculation reactor 5, and the centrifuge 7 are sequentially arranged in the treatment system from upstream to downstream. The working principle of the treatment system is as follows: first, the COD-containing wastewater is subjected to neutralization reaction and sedimentation in the neutralization tank 3 to obtain a suspension and a precipitate; then, the suspension is subjected to first filtration in the filter 4 to obtain a slurry and a first filtrate; then, the first filtrate is subjected to flocculation reaction in the flocculation reactor 5 to obtain a clear liquid and a particulate matter; and at the same time, the slurry is subjected to second filtration in the centrifuge 7 to obtain a filter residue and a second filtrate.

[0030] Through the above technical solution, for the suspension discharged from the neutralization tank 3, the filter 4 and the flocculation reactor 5 are further arranged in the COD-containing wastewater treatment system, so that the suspension is first subjected to filtration treatment in the filter 4, then the filtrate is subjected to flocculation treatment in the flocculation reactor 5, and finally the clear liquid is discharged. Through multi-stage treatment of the COD-containing wastewater, different concentrations and water qualities of the COD-containing wastewater are treated, the problem that the prior art cannot effectively treat low-concentration COD-containing wastewater is solved, and the removal rate of COD is significantly improved, so that the clear liquid can be finally discharged up to standard.

[0031] It is detected that the COD content in the current production process is 1.73*10 3 to 3.42*10 3 mg / L, which can be reduced to below 100 mg / L after being treated by the treatment system and stably discharged up to standard.

[0032] In some embodiments, the number of filters 4 is one or more.

[0033] As shown in Figure 1 , the number of filters 4 can be set according to the treatment amount of the COD-containing wastewater, and the treatment system can include only one filter 4 or multiple filters 4. The number of filters 4 is preferably 2-5.

[0034] In some embodiments, the number of filters 4 is multiple, and the multiple filters 4 are connected in parallel, and each filter 4 is connected with one flocculation reactor 5.

[0035] As shown in Figure 1As shown, the filter 4 filters the obtained first filtrate to automatically overflow from the first outlet to the flocculation reactor 5. In the treatment system, each filter 4 is arranged to correspond to connecting one flocculation reactor 5 respectively, so that the first filtrate output from each filter 4 can be processed in time, and compared with the way of connecting multiple filters 4 to one flocculation reactor 5, such a way can obviously improve the effect of removing COD by flocculation reaction, and reduce the COD content in the discharged clear liquid as much as possible. In some other embodiments, multiple filters 4 can also be connected to one flocculation reactor 5 according to the situation, for example, when the COD wastewater treatment amount is small.

[0036] In some embodiments, the wastewater storage tank 1 and the first dosing device 2 are further included, the outlet of the wastewater storage tank 1 is connected with the first inlet of the neutralization tank 3, and the outlet of the first dosing device 2 is connected with the second inlet of the neutralization tank 3.

[0037] As shown in the figure, Figure 1 The wastewater pipeline 9 is connected between the wastewater storage tank 1 and the neutralization tank 3 for conveying the COD wastewater, and the neutralizing agent pipeline 10 is connected between the first dosing device 2 and the neutralization tank 3 for conveying the neutralizing agent (for example, calcium hydroxide, calcium oxide, etc.). The COD wastewater and the neutralizing agent perform a neutralization reaction in the neutralization tank 3 to generate a suspension and a precipitate (for example, calcium oxalate precipitate). In some other embodiments, the wastewater pipeline 9 and the neutralizing agent pipeline 10 can also enter the neutralization tank 3 from the same inlet.

[0038] In some embodiments, the second dosing device 6 is further included, and the outlet of the second dosing device 6 is connected with the inlet of the flocculation reactor 5.

[0039] As shown in the figure, Figure 1 The flocculant pipeline 14 is connected between the second dosing device 6 and the flocculation reactor 5, and the flocculant pipeline 14 can be connected into the first filtrate pipeline 13 to enter the flocculation reactor 5 together with the first filtrate. When there are multiple filters 4, the second dosing device 6 is connected with the multiple filters 4 respectively. Specifically, at this time, the flocculant pipeline 14 can include a main pipeline and multiple branch pipelines, the main pipeline is connected with the outlet of the second dosing device 6, and the multiple branch pipelines are connected with the multiple filters 4 respectively and connected into the main pipeline.

[0040] In some embodiments, the control system 8 is further included, and the control system 8 is in communication connection with the neutralization tank 3, the filter 4, the flocculation reactor 5 and the centrifuge 7 to realize automatic feeding and discharging.

[0041] As shown in the figure, Figure 1 The control system 8 can be a control cabinet with a pre-designed programmable control system, which is in communication connection with the neutralization tank 3, the filter 4, the flocculation reactor 5 and the centrifuge 7 (including various pipelines connected with the foregoing devices) respectively, and realizes automatic control of the entire treatment system according to the set parameters.

[0042] Specifically, each inlet and outlet of the neutralization tank 3, the filter 4, the flocculation reactor 5 and the centrifuge 7 is provided with a feeding valve 20 and a discharging valve 21, and a conveying pump 19 can be arranged on each pipeline for transporting materials. The control system 8 can be connected in communication with the conveying pump 19, the feeding valve 20 and the discharging valve 21. The neutralization tank 3 can feed or discharge according to the liquid level and the reaction time, and the conveying pump 19 can be started or stopped to feed the filter 4 according to the reaction time, the liquid level and the pressure of the filter 4; the filter 4 can automatically backwash or continuously feed according to the pressure difference and the set time; the flocculation reactor 5 can automatically feed or discharge according to the pressure and the internal liquid level at the filter 3, and the system liquid level and pressure interlocking are arranged.

[0043] In some embodiments, the outlet of the neutralization tank 3 is connected with the inlet of the filter 4 through a suspension pipeline 11, and the suspension pipeline 11 is provided with a conveying pump 19.

[0044] As shown in Figure 1 when the filter 4 has multiple, the neutralization tank 3 is connected with multiple filters 4 respectively. Specifically, the suspension pipeline 11 can include a main pipeline and multiple branch pipelines, the main pipeline is connected with the outlet of the neutralization tank 3, and the multiple branch pipelines are connected with the multiple filters 4 respectively and connected into the main pipeline, and each branch pipeline is provided with a conveying pump 19.

[0045] In some embodiments, the second outlet of the filter 4 is connected with the inlet of the centrifuge 7 through a slurry pipeline 12, and the slurry pipeline 12 is provided with a conveying pump 19.

[0046] As shown in Figure 1 when the filter 4 has multiple, the centrifuge 7 is connected with multiple filters 4 respectively. Specifically, the slurry pipeline 12 can include a main pipeline and multiple branch pipelines, the main pipeline is connected with the inlet of the centrifuge 7, and the multiple branch pipelines are connected with the multiple filters 4 respectively and connected into the main pipeline.

[0047] In some embodiments, the first outlet of the flocculation reactor 5 is connected with a particulate matter recovery pipeline 16, and the second outlet of the flocculation reactor 5 is connected with a clear liquid pipeline 15.

[0048] As shown in Figure 1 the particulate matter recovery pipeline 16 can be connected with a storage tank or other recovery device for conveying the particulate matter in the flocculation reactor 5; and the clear liquid pipeline 15 can be provided with a sampling port for real-time detection and monitoring of the COD content in the clear liquid to be discharged from the system.

[0049] When the flocculation reactors 5 are multiple, the particle recovery pipeline 16 can comprise a main pipeline connected with the inlet of the recovery device and multiple branch pipelines respectively connected with the first outlets of the multiple flocculation reactors 5 and connected into the main pipeline.

[0050] When the flocculation reactors 5 are multiple, the clear liquid pipeline 15 can comprise a main pipeline extending to outside of the treatment system and multiple branch pipelines respectively connected with the second outlets of the multiple flocculation reactors 5 and connected into the main pipeline.

[0051] In some embodiments, the first outlet of the centrifuge 7 is connected with a filter residue recovery pipeline 17, and the second outlet of the centrifuge 7 is connected with the third inlet of the neutralization tank 3.

[0052] As shown in Figure 1 the centrifuge 7 is used for solid-liquid separation of the slurry filtered by the filter 4 to obtain filter residue and second filtrate, the filter residue recovery pipeline 17 can be connected with a recovery device such as a storage tank, and the second outlet of the centrifuge 7 can be connected with the second filtrate pipeline 18 between the third inlet of the neutralization tank 3. In some other embodiments, the second filtrate pipeline 18 can also be connected into the wastewater pipeline 9.

[0053] In some embodiments, the filter 4 is a drum filter or a belt filter. Preferably, the filter 4 is a drum filter, which comprises a filter cylinder, a drum membrane, a membrane support, a pipeline, a liquid level meter, a pressure transmitter and an automatic inlet and outlet valve, and can be used for treating various viscous and high-concentration particles, slurry and filter materials, and has a very wide application range.

[0054] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited thereto. Within the technical concept of the present application, the technical solution of the present application can be variously modified, including various specific technical features combined in any suitable manner. In order to avoid unnecessary repetition, the present application will not be described again for various possible combination manners. However, these simple modifications and combinations should also be regarded as disclosed contents of the present application, and all belong to the protection scope of the present application.

Claims

1. A system for treating COD-containing wastewater, characterized by comprising: The device comprises: a neutralization tank (3), a filter (4) connected with the outlet of the neutralization tank (3), a flocculation reactor (5) connected with the first outlet of the filter (4), and a centrifuge (7) connected with the second outlet of the filter (4); wherein the neutralization tank (3) is used for the reaction of the COD-containing wastewater and the neutralizing agent and the sedimentation to obtain a suspension and a precipitate; the filter (4) is used for receiving and filtering the suspension from the neutralization tank (3) to obtain a slurry and a first filtrate; the flocculation reactor (5) is used for receiving the first filtrate from the filter (4) and performing a flocculation reaction to obtain a clear liquid and a particulate; and the centrifuge (7) is used for receiving and filtering the slurry from the filter (4) to obtain a filter residue and a second filtrate.

2. The COD-containing wastewater treatment system according to claim 1, characterized by, The number of the filter (4) is set to one or more.

3. The COD-containing wastewater treatment system according to claim 1, wherein The number of the filter (4) is set to multiple, and the multiple filters (4) are connected in parallel, and each first outlet of the filter (4) is connected with one flocculation reactor (5).

4. The COD-containing wastewater treatment system according to claim 1, wherein Further comprising a wastewater storage tank (1) and a first dosing device (2), wherein the outlet of the wastewater storage tank (1) is connected with the first inlet of the neutralization tank (3), and the outlet of the first dosing device (2) is connected with the second inlet of the neutralization tank (3).

5. The COD-containing wastewater treatment system according to claim 1, wherein Further comprising a second dosing device (6), wherein the outlet of the second dosing device (6) is connected with the inlet of the flocculation reactor (5).

6. The COD-containing wastewater treatment system of claim 1, wherein Further comprising a control system (8) which is communicatively connected with the neutralization tank (3), the filter (4), the flocculation reactor (5), and the centrifuge (7) to realize automatic feeding and discharging.

7. The COD-containing wastewater treatment system according to any one of claims 1 to 6, wherein A suspension pipeline (11) is connected between the outlet of the neutralization tank (3) and the inlet of the filter (4), and a delivery pump (19) is arranged on the suspension pipeline (11).

8. The COD-containing wastewater treatment system according to any one of claims 1 to 6, wherein A slurry pipeline (12) is connected between the second outlet of the filter (4) and the inlet of the centrifuge (7), and a delivery pump (19) is arranged on the slurry pipeline (12).

9. The COD-containing wastewater treatment system according to any one of claims 1 to 6, wherein A particulate recovery pipeline (16) is connected with the first outlet of the flocculation reactor (5), and a clear liquid pipeline (15) is connected with the second outlet of the flocculation reactor (5).

10. The COD-containing wastewater treatment system according to any one of claims 1 to 6, wherein A filter residue recovery pipeline (17) is connected with the first outlet of the centrifuge (7), and the second outlet of the centrifuge (7) is connected with the third inlet of the neutralization tank (3).

11. The COD-containing wastewater treatment system according to any one of claims 1 to 6, wherein The filter (4) is a drum filter or a belt filter.

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