Isopropanol wastewater treatment system

Abstract

The utility model provides a kind of isopropanol wastewater treatment system.The system includes distillation module, denitrification module and AO biochemical module;The inlet of denitrification module is also connected with nitrate nitrogen wastewater source, and the outlet of denitrification module is connected with the inlet of AO biochemical module.The system can recover most isopropanol in isopropanol wastewater, realize resource utilization, and convert nitrate nitrogen in nitrate nitrogen wastewater into nitrogen by denitrification, remove carbon source at the same time, greatly reduce oxygen consumption and sludge production during subsequent AO biochemical treatment, reduce wastewater treatment cost;At the same time, the treatment effect of the treatment system is better, can greatly reduce COD value and TN content in wastewater.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment and waste liquid resource utilization technology, specifically relating to an isopropanol wastewater treatment system. Background Technology

[0002] In the semiconductor and electronics industries, isopropanol (IPA) is commonly used to clean precision electronic components such as chips and LCD displays. The wastewater after cleaning contains a large amount of isopropanol, resulting in a high concentration of organic matter (calculated as chemical oxygen demand, COD). Direct biological treatment would be energy-intensive, generate a large amount of biological sludge (solid waste), and waste resources. Furthermore, even after distillation to recover isopropanol from this type of wastewater, the residual liquid still contains 1%-3% isopropanol, and the COD concentration in the residual liquid remains high. Traditional anaerobic-aerobic (AO) biological treatment still requires a high oxygen supply. Utility Model Content

[0003] To address the shortcomings of existing technologies in treating isopropanol wastewater due to its high COD concentration, this invention provides an isopropanol wastewater treatment system. This system not only recovers most of the isopropanol from the wastewater, achieving resource utilization, but also converts nitrate nitrogen in nitrate nitrogen wastewater into nitrogen gas through denitrification, while simultaneously removing carbon sources. This significantly reduces oxygen consumption and sludge production during subsequent AO biological treatment, lowering wastewater treatment costs. Furthermore, the system exhibits superior treatment efficiency, substantially reducing COD and TN levels in the wastewater. Therefore, this invention significantly reduces operating costs, delivering substantial economic and environmental benefits, and demonstrating significant emission reduction effects.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution: This invention provides an isopropanol wastewater treatment system, which includes a distillation module, a denitrification module, and an AO biochemical module; the inlet of the distillation module is connected to an isopropanol wastewater source, and the wastewater outlet of the distillation module is connected to the inlet of the denitrification module; the inlet of the denitrification module is also connected to a nitrate nitrogen wastewater source, and the outlet of the denitrification module is connected to the inlet of the AO biochemical module.

[0005] In this invention, high-concentration isopropanol wastewater is recycled in a distillation module, recovering most of the isopropanol.

[0006] In a preferred embodiment, the distillation module includes a distillation device and a rectification device; the distillation device is used for primary distillation of isopropanol wastewater, and the rectification device is used for rectification of the recovered liquid obtained after primary distillation; the inlet of the distillation device is connected to the isopropanol wastewater source, the wastewater outlet of the distillation device is connected to the inlet of the denitrification module, and the recovered liquid outlet of the distillation device is connected to the rectification device.

[0007] In a further preferred embodiment, the distillation module further includes a first conditioning tank, which is located at the wastewater outlet of the distillation apparatus and is used to adjust the pH value of the residual wastewater generated during distillation.

[0008] In this invention, the residual wastewater and wastewater containing high concentrations of nitrate nitrogen are treated together in a denitrification module. Denitrification converts nitrate nitrogen into nitrogen gas for removal while removing a large amount of carbon source.

[0009] In a preferred embodiment, the denitrification module includes a denitrification tank containing conventional denitrifying bacteria for denitrifying the mixture of residual wastewater from isopropanol distillation and nitrate nitrogen wastewater.

[0010] In a preferred embodiment, the AO biochemical module includes an anaerobic biochemical treatment tank and an aerobic biochemical treatment tank, used to remove the remaining total nitrogen (TN) and organic matter (COD) from the waste liquid treated by the denitrification module.

[0011] In a preferred embodiment, the isopropanol wastewater treatment system further includes a sedimentation module, the inlet of which is connected to the outlet of the AO biochemical module.

[0012] In a further preferred embodiment, the outlet of the sedimentation module is connected to the inlet of the denitrification module.

[0013] In a further preferred embodiment, the outlet of the precipitation module is connected to the inlet of the AO biochemical module.

[0014] In a further preferred embodiment, the sedimentation module includes a secondary sedimentation tank and a coagulation sedimentation tank; the inlet of the secondary sedimentation tank is connected to the outlet of the AO biochemical module, and the outlet of the secondary sedimentation tank is connected to the inlet of the coagulation sedimentation tank.

[0015] In a further preferred embodiment, the outlet of the secondary sedimentation tank is also connected to the inlet of the denitrification module, so as to allow some of the sludge in the secondary sedimentation tank to flow back to the denitrification module and replenish the denitrifying bacteria lost in the denitrification module.

[0016] In a further preferred embodiment, the outlet of the secondary sedimentation tank is also connected to the inlet of the AO biological module, so as to allow some of the sludge in the secondary sedimentation tank to be returned to the AO biological module.

[0017] In a preferred embodiment, the inlet of the AO biochemical module is also connected to a daily sewage source; a second regulating tank is also provided between the AO biochemical module and the daily sewage source to regulate the pH value of the daily sewage source.

[0018] Compared with the prior art, the beneficial effects of this utility model are: 1. This treatment system can recover most of the isopropanol in high-concentration isopropanol wastewater for resource utilization, significantly reducing resource waste and carbon emissions, lowering the cost of subsequent wastewater discharge treatment, and reducing the scale and investment of wastewater treatment facilities. 2. This treatment system can convert nitrate nitrogen into nitrogen gas for removal while removing a large amount of carbon source, which greatly reduces the oxygen demand and sludge production of subsequent AO biological treatment, thereby reducing operating costs and also reducing the scale and investment of subsequent wastewater treatment facilities.

[0019] 3. The treatment system has a good treatment effect and can significantly reduce the COD value and TN content in wastewater; specifically, the effluent COD of the AO treatment module is below 100 mg / L and TN is below 25 mg / L.

[0020] 4. The operation and processing results of this processing system are relatively stable. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the isopropanol wastewater treatment system of Embodiment 1 of this utility model; Figure 2 This is a graph showing the change in COD index of the residual wastewater entering the denitrification tank in Embodiment 2 of this utility model; Figure 3 This is a graph showing the change in TN index of wastewater containing high concentration of nitrate nitrogen entering the denitrification tank in Embodiment 2 of this utility model; Figure 4 This is a graph showing the change in COD index in the denitrification tank of Embodiment 2 of this utility model; Figure 5 This is a graph showing the change in TN index in the denitrification tank of Embodiment 2 of this utility model; Figure 6 This is a graph showing the change in COD index of AO biochemical effluent in Embodiment 2 of this utility model; Figure 7 This is a graph showing the change in TN index of AO biochemical effluent in Embodiment 2 of this utility model.

[0022] Explanation of reference numerals in the attached figures: Distillation unit 1, rectification unit 2, first equalization tank 3, denitrification tank 4, second equalization tank 5, AO biochemical module 6, secondary sedimentation tank 7, coagulation sedimentation tank 8. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result of the description. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solution of the present invention without departing from the scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0024] The following embodiment provides an isopropanol wastewater treatment system, which includes a distillation module, a denitrification module, and an AO biological module; the inlet of the distillation module is connected to an isopropanol wastewater source, and the wastewater outlet of the distillation module is connected to the inlet of the denitrification module; the inlet of the denitrification module is also connected to a nitrate nitrogen wastewater source, and the outlet of the denitrification module is connected to the inlet of the AO biological module.

[0025] In some embodiments, the distillation module includes a distillation apparatus and a rectification apparatus; the distillation apparatus is used for primary distillation of isopropanol wastewater, and the rectification apparatus is used for rectification of the recovered liquid obtained after primary distillation; the inlet of the distillation apparatus is connected to the isopropanol wastewater source, the wastewater outlet of the distillation apparatus is connected to the inlet of the denitrification module, and the recovered liquid outlet of the distillation apparatus is connected to the rectification apparatus.

[0026] In the following embodiments, the isopropanol wastewater is distilled by a distillation device to obtain isopropanol recovery liquid and residual wastewater; the isopropanol recovery liquid can be further purified by a distillation device, and the residual wastewater can be further treated by a denitrification module.

[0027] In the following embodiments, the isopropanol wastewater treatment system can treat high-concentration isopropanol wastewater; preferably, the COD of the isopropanol wastewater is 150,000-500,000 mg / L; preferably, the COD of the residual wastewater after distillation is 10,000-70,000 mg / L.

[0028] In a specific implementation, the distillation module further includes a first regulating tank, which is located at the wastewater outlet of the distillation apparatus and is used to regulate the pH value of the residual wastewater generated during distillation; the first regulating tank can also be used to temporarily store the residual wastewater generated during distillation.

[0029] In the following embodiments, the nitrate nitrogen wastewater may be high-concentration nitrate nitrogen wastewater containing nitrate nitrogen; preferably, the total nitrogen concentration of the nitrate nitrogen wastewater is 20,000-40,000 mg / L.

[0030] In the following embodiments, the residual wastewater generated after the isopropanol wastewater is distilled by the distillation module is subjected to denitrification with the nitrate nitrogen wastewater to remove nitrogen, thereby converting nitrate nitrogen into nitrogen gas and consuming a large amount of carbon source.

[0031] In the following embodiments, preferably, the denitrification module includes a denitrification tank containing conventional denitrifying bacteria for denitrifying a mixture of isopropanol wastewater (after distillation) and nitrate nitrogen wastewater. Preferably, the residence time of the mixed wastewater in the denitrification tank is 32-48 hours.

[0032] In one embodiment, the temperature of the denitrification tank is 30-37°C; the pH of the mixed wastewater in the denitrification tank is 7.5-8.7; and the total nitrogen (TN) load of the denitrification tank is 0.05-0.08 kgTN / (kgMLss·d); wherein, the total nitrogen load refers to the fluctuation range of the amount of wastewater treated daily by the device or system.

[0033] In one embodiment, the ratio of carbon content in the residual wastewater after distillation of isopropanol wastewater to total nitrogen content in the nitrate nitrogen wastewater is (5-8):1; here, the content ratio is a mass ratio.

[0034] In one embodiment, the COD of the residual wastewater after distillation of the isopropanol wastewater is 50,000 mg / L, and the total nitrogen content of the nitrate nitrogen wastewater is 30,000 mg / L; the denitrification tank has a treatment capacity of 21-33 m³ for the residual wastewater. 3 / d, the treatment capacity of the nitrate nitrogen wastewater is 7m³ / d. 3 / d.

[0035] In the following embodiments, the pH of the nitrate nitrogen wastewater is 9-11 before it is introduced into the denitrification module. When the treatment volume is large, the pH of the waste liquid in the denitrification tank of the denitrification module will gradually rise, and the pH value needs to be adjusted with acid.

[0036] In the following embodiments, the AO biochemical module is used to generate an anaerobic-aerobic process (AO process).

[0037] In some embodiments, the AO biochemical module includes an anaerobic biochemical treatment tank and an aerobic biochemical treatment tank, used to remove the remaining total nitrogen (TN) and organic matter (COD) from the waste liquid treated by the denitrification module.

[0038] In the following embodiments, preferably, the residence time of the waste liquid treated by the denitrification module in the facultative anaerobic biological treatment tank is 4-8 h; preferably, the residence time of the waste liquid treated by the denitrification module in the aerobic biological treatment tank is 24-48 h.

[0039] In some embodiments, the isopropanol wastewater treatment system further includes a sedimentation module, the inlet of which is connected to the outlet of the AO biochemical module.

[0040] In a specific implementation, the outlet of the sedimentation module is connected to the inlet of the denitrification module.

[0041] In a specific implementation, the outlet of the precipitation module is connected to the inlet of the AO biochemical module.

[0042] In a specific embodiment, the sedimentation module includes a secondary sedimentation tank and a coagulation sedimentation tank; the inlet of the secondary sedimentation tank is connected to the outlet of the AO biochemical module, and the outlet of the secondary sedimentation tank is connected to the inlet of the coagulation sedimentation tank.

[0043] In a specific implementation, the outlet of the secondary sedimentation tank is also connected to the inlet of the denitrification module, so as to allow some of the sludge in the secondary sedimentation tank to flow back into the denitrification module to replenish the denitrifying bacteria lost in the denitrification module.

[0044] In the following embodiments, the coagulation sedimentation tank may contain or have added PAC (polyaluminum chloride) and PAM (polyacrylamide).

[0045] In the following embodiments, preferably, the sludge return flow rate in the secondary sedimentation tank is such that the TDS (total dissolved solids) of the mixed wastewater in the denitrification module is maintained below 6000 mg / L; while the retention time of the mixed wastewater in the denitrification module is 32-48 hours.

[0046] In a specific implementation, the outlet of the secondary sedimentation tank is also connected to the inlet of the AO biological module, so as to allow some of the sludge in the secondary sedimentation tank to flow back into the AO biological module.

[0047] In some embodiments, the inlet of the AO biochemical module is also connected to a daily sewage source; a second regulating tank is also provided between the AO biochemical module and the daily sewage source for adjusting the pH value of the daily sewage source.

[0048] The daily wastewater sources may include domestic sewage and workshop drainage.

[0049] In one embodiment, the process of treating isopropanol wastewater using the isopropanol wastewater treatment system includes the following steps: S1. Distillation treatment: The high-concentration isopropanol wastewater is first distilled to obtain isopropanol recovery liquid and residual wastewater with a concentration of about 85%; among which, the COD of the high-concentration isopropanol wastewater is 150,000-500,000 mg / L. The isopropanol recovery liquid is then distilled to obtain isopropanol with a purity of over 99.5%. The residual liquid wastewater is then sent to the first conditioning tank of the distillation module for further treatment. S2, Denitrification treatment: The residual wastewater and high-concentration nitrate nitrogen wastewater are mixed in the denitrification tank of the denitrification module to carry out denitrification and denitrification, converting nitrate nitrogen into nitrogen gas for removal, and removing carbon source from the residual wastewater at the same time. S3, AO biological treatment: The waste liquid after the denitrification module is passed into the AO biological module for AO biological treatment, which includes facultative anaerobic biological treatment and aerobic biological treatment to further remove the remaining total nitrogen TN and organic matter COD; S4. Sedimentation treatment: The waste liquid treated by the AO biochemical module is passed into the sedimentation module, and discharged after sedimentation.

[0050] Example 1 This embodiment discloses an isopropanol wastewater treatment system. Figure 1 This is a schematic diagram of the isopropanol wastewater treatment system in this embodiment.

[0051] The isopropanol wastewater treatment system includes a distillation module, a denitrification module, an AO biochemical module 6, and a sedimentation module; The distillation module includes a distillation unit 1, a rectification unit 2, and a first equalization tank 3. The distillation unit 1 is used for the initial distillation of isopropanol wastewater, the rectification unit 2 is used for the rectification of the recovered liquid obtained after the initial distillation, and the first equalization tank 3 is used to temporarily store the residual wastewater obtained from the distillation. The inlet of the distillation unit 1 is connected to the isopropanol wastewater source, the wastewater outlet of the distillation unit 1 is connected in sequence to the first equalization tank 2 and the inlet of the denitrification module, and the recovered liquid outlet of the distillation unit 1 is connected to the rectification unit 2. The denitrification module includes a denitrification tank 4; the inlet of the denitrification tank 4 is connected to the first equalization tank 3 and also to the nitrate nitrogen wastewater source, and the outlet of the denitrification tank 4 is connected to the inlet of the AO biological module 6. The AO biochemical module 6 includes an anaerobic biochemical treatment tank and an aerobic biochemical treatment tank, which are used to remove the remaining total nitrogen (TN) and organic matter (COD) in the wastewater after denitrification treatment. The inlet of the AO biochemical module 6 is also connected to the daily sewage source. A second equalization tank 5 is also provided between the AO biochemical module 6 and the daily sewage source to adjust the pH value of the daily sewage source. The sedimentation module includes a secondary sedimentation tank 7 and a coagulation sedimentation tank 8. The inlet of the secondary sedimentation tank 7 is connected to the outlet of the AO biological module 6, and the outlet of the secondary sedimentation tank 7 is connected to the inlet of the coagulation sedimentation tank 8. The outlet of the secondary sedimentation tank 7 is also connected to the inlet of the denitrification tank 4 and the inlet of the AO biological module 6, respectively, so as to allow some of the sludge in the secondary sedimentation tank 7 to be returned to the denitrification module to replenish the denitrifying bacteria lost in the denitrification module.

[0052] Example 2 This embodiment discloses a method for treating isopropanol wastewater, which uses the isopropanol wastewater treatment system described in Example 1, and includes the following steps: S1. Distillation treatment: High-concentration isopropanol wastewater (with COD of 150,000-500,000 mg / L) is purified by primary distillation in the primary distillation vessel. The top temperature of the primary distillation vessel is controlled at around 85°C to obtain isopropanol recovery liquid and residual wastewater. The isopropanol recovery liquid is then purified by distillation in a rectification device to obtain isopropanol with a purity of over 99.5%.

[0053] The residual wastewater obtained from distillation is stored in the first equalization tank, with a COD of 10,000-70,000 mg / L; S2. Denitrification Treatment: The residual wastewater in the equalization tank is used as a carbon source and mixed with high-concentration nitrate nitrogen wastewater in the denitrification tank. Denitrifying bacteria are added to carry out denitrification. The residence time of the mixed wastewater in the denitrification tank is 32-48 hours, which converts nitrate nitrogen into nitrogen gas and removes a large amount of carbon source at the same time. The total nitrogen concentration of the high-concentration nitrate nitrogen wastewater is 20,000-40,000 mg / L. The two wastewater streams of residual wastewater and nitrate nitrogen wastewater are fed into the tank at a C / TN mass ratio of (5-8):1, and the total nitrogen load is 0.05-0.08 kgTN / (kgMLss·d). The temperature of the denitrification tank is 30-37℃, and the pH of the mixed wastewater in the denitrification tank is 7.5-8.7. S3, AO biological treatment: The wastewater after denitrification is fed into the AO biological treatment tank for biological treatment; the AO biological treatment includes facultative anaerobic biological treatment and aerobic biological treatment; the effluent from the denitrification tank enters the AO biological treatment tank to further degrade and remove the remaining TN and COD; the wastewater retention time for facultative anaerobic biological treatment is 4-8 hours, and the wastewater retention time for aerobic biological treatment is 24-36 hours; S4. Sedimentation treatment: The waste liquid after AO biochemical treatment is passed into the secondary sedimentation tank. After sedimentation, it is passed into the coagulation sedimentation tank, and PAC and PAM are added. After coagulation sedimentation, the waste liquid is discharged in compliance with standards.

[0054] In this process, some of the sludge from the secondary sedimentation tank needs to be returned to the denitrification tank to replenish the denitrifying bacteria lost in the denitrification tank. The key to controlling the sludge return flow rate is to maintain the TDS in the denitrification tank within 6000 mg / L, while ensuring that the hydraulic retention time in the denitrification tank is 32-48 hours, so as to ensure efficient and stable denitrification reaction in the denitrification tank.

[0055] Example 1 This effect example is the monitoring results of wastewater in each step of the treatment method in Example 2, including the residual wastewater entering the denitrification tank, the changes in COD index in the denitrification tank and the AO biochemical effluent, and the changes in TN index in the high-concentration nitrate nitrogen wastewater entering the denitrification tank, the denitrification tank and the AO biochemical effluent; the wastewater sampling frequency is twice a day.

[0056] Within the time frame of the denitrification tank and the AO biological effluent discharge, batch-by-batch COD data of the residual wastewater in the first equalization tank were collected. Specifically, samples were taken and tested whenever residual wastewater was discharged into the tank. Figure 2 . Figure 2 This is a graph showing the change in COD index of the residual wastewater entering the denitrification tank in Example 2. (Source: [Graph showing COD index change in Example 2]) Figure 2 It can be seen that the COD of the residual wastewater is 10,000-70,000 mg / L.

[0057] Within the time frame of the denitrification tank and the AO biological effluent, batches of high-concentration nitrate nitrogen wastewater (TN) were collected for TN variation data. Specifically, samples were taken and tested whenever changes occurred in the wastewater samples. Figure 3 . Figure 3 This is a graph showing the change in TN (total nitrogen) index of the high-nitrate-nitrogen wastewater entering the denitrification tank in Example 2. Figure 3 It is known that the total nitrogen (TN) concentration in nitrate nitrogen wastewater is 20,000-40,000 mg / L.

[0058] During the stable operation of the treatment system, effluent samples from the denitrification tank were taken twice daily to measure COD and TN levels. Figure 4 and Figure 5 . Figure 4 This is a graph showing the changes in COD levels in the denitrification tank of Example 2. Figure 5 This is a graph showing the changes in TN (total nitrogen) levels within the denitrification tank. Figure 4 As can be seen from the curves, when the COD in the denitrification tank is maintained within a relatively low concentration range, the carbon source utilization rate of this treatment method is high. Figure 5 As can be seen from the curve, the TN concentration in the denitrification tank is maintained at a low level, indicating that the denitrification efficiency of this treatment method is high.

[0059] During the stable operation of the treatment system, effluent samples from the AO biological treatment were taken twice daily to measure COD and TN levels. Figure 6 and Figure 7 . Figure 6 This is a graph showing the changes in COD levels in the AO biochemical effluent from Example 2. Figure 7 This is a graph showing the changes in TN (total nitrogen) index in the AO biochemical effluent from Example 2. (Source: [Graph showing changes in TN index in AO biochemical effluent from Example 2]) Figure 6 It can be seen that the COD of the effluent is below 100 mg / L, and may even reach as low as 18 mg / L, which meets the discharge standards; Figure 7It can be seen that the total nitrogen (TN) of the effluent is below 25 mg / L, and can even reach as low as 5 mg / L, which meets the discharge standards. The operation and treatment results of the treatment system are relatively stable.

[0060] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present utility model should be included within the protection scope of the present utility model.

[0061] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An isopropanol wastewater treatment system, characterized in that, It includes a distillation module, a denitrification module, and an AO biochemical module; The inlet of the distillation module is connected to the isopropanol wastewater source, and the wastewater outlet of the distillation module is connected to the inlet of the denitrification module. The inlet of the denitrification module is also connected to a nitrate nitrogen wastewater source, and the outlet of the denitrification module is connected to the inlet of the AO biochemical module.

2. The isopropanol wastewater treatment system as described in claim 1, characterized in that, The distillation module includes a distillation apparatus and a rectification apparatus; the distillation apparatus is used for primary distillation of isopropanol wastewater, and the rectification apparatus is used for rectification of the recovered liquid obtained after primary distillation; The inlet of the distillation unit is connected to the isopropanol wastewater source, the wastewater outlet of the distillation unit is connected to the inlet of the denitrification module, and the recovery liquid outlet of the distillation unit is connected to the rectification unit.

3. The isopropanol wastewater treatment system as described in claim 2, characterized in that, The distillation module also includes a first conditioning tank, which is located at the wastewater outlet of the distillation device and is used to adjust the pH value of the residual wastewater generated during distillation.

4. The isopropanol wastewater treatment system as described in claim 1, characterized in that, The denitrification module includes a denitrification tank containing denitrifying bacteria, used to cause a denitrification reaction between the residual wastewater after distillation of isopropanol wastewater and the mixed wastewater containing nitrate nitrogen.

5. The isopropanol wastewater treatment system as described in claim 1, characterized in that, The AO biochemical module includes an anaerobic biochemical treatment tank and an aerobic biochemical treatment tank, which are used to remove the remaining total nitrogen (TN) and organic matter (COD) from the waste liquid after the denitrification module treatment.

6. The isopropanol wastewater treatment system as described in claim 1, characterized in that, The isopropanol wastewater treatment system also includes a sedimentation module, the inlet of which is connected to the outlet of the AO biochemical module.

7. The isopropanol wastewater treatment system as described in claim 6, characterized in that, The outlet of the sedimentation module is connected to the inlet of the denitrification module and the inlet of the AO biochemical module, respectively.

8. The isopropanol wastewater treatment system as described in claim 6, characterized in that, The sedimentation module includes a secondary sedimentation tank and a coagulation sedimentation tank; the inlet of the secondary sedimentation tank is connected to the outlet of the AO biochemical module, and the outlet of the secondary sedimentation tank is connected to the inlet of the coagulation sedimentation tank.

9. The isopropanol wastewater treatment system as described in claim 8, characterized in that, The outlet of the secondary sedimentation tank is also connected to the inlet of the denitrification module; The outlet of the secondary sedimentation tank is also connected to the inlet of the AO biochemical module.

10. The isopropanol wastewater treatment system as described in claim 1, characterized in that, The inlet of the AO biochemical module is also connected to a daily sewage source; a second regulating tank is also provided between the AO biochemical module and the daily sewage source to regulate the pH value of the daily sewage source.

Images