A method for treating acidic industrial wastewater

Abstract

The invention relates to a method for treating acidic industrial sewage. The invention can remove most of the pollutants in the industrial sewage. The sewage can be effectively purified by adjusting the pH value of the acidic sewage and filtering the sewage. Organic matter in the sewage is killed by aeration. Finally, ultrafiltration is performed through a hollow fiber membrane to filter out small molecular compounds in the sewage. The acidic industrial sewage can be thoroughly purified, especially the acidic industrial sewage containing organic matter. The required purification materials are very common and have no pollution to the environment.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a method for treating acidic industrial sewage. Background Art

[0002] For cellulose manufacturers, in the process of extracting cellulose from wood chips, a large amount of acidic substances are used to help decompose wood pulp, which will produce a large amount of acidic wastewater that must be treated before discharge to reduce pollution to the environment. Summary of the invention

[0003] In view of the above, the present invention is aimed at the above technical problems and provides a method for treating acidic industrial wastewater.

[0004] A method for treating acidic industrial wastewater, characterized in that it comprises the following steps:

[0005] S1 filtration: filter the acidic sewage in the sewage pool to remove large particles of waste in the acidic sewage;

[0006] S2 Neutralization: Pump the filtered acidic sewage from the sewage pool into the neutralization tank, add an appropriate amount of sodium hydroxide, and adjust the pH to 9-9.6;

[0007] S3 coagulation: pump the acidic sewage from the neutralization tank into the coagulation tank, first add 10% basic aluminum chloride, react for 5-10 minutes, then add 0.1% polyacrylamide, react for 5-10 minutes, make the pH reach 7.2-7.85, and let it stand for 30 minutes after coagulation is completed;

[0008] S4 filtration: Use filter press to filter out the flocculent suspended matter after coagulation, and the pH reaches 6.8-7.4 after filtration;

[0009] S5 precipitation: precipitation is carried out in a sedimentation tank, and the precipitation time is 0.5-1 hour;

[0010] S6 PH adjustment: transfer the supernatant from the sedimentation tank to the treatment tank, add appropriate amount of sulfuric acid and ferrous sulfate heptahydrate, stir for about 10 minutes, and adjust the pH to 2.4;

[0011] S7 oxidation: add hydrogen peroxide and oxidize for 3-5 hours to make the pH reach 2.8-3.2;

[0012] S8 Aeration: Transfer the sewage to the aeration tank and blow air into the sewage to increase the oxygen content of the sewage;

[0013] S9 secondary processing: repeat the above steps S2-S5;

[0014] S10 ultrafiltration: uses hollow fiber membranes to filter out large particles in sewage;

[0015] S11 collection: discharge and collect the clean water after ultrafiltration.

[0016] The method for treating acidic industrial wastewater provided by the present invention can be further configured to produce industrial alcohol after collecting filtered impurities in the S10 ultrafiltration.

[0017] The method for treating acidic industrial wastewater provided by the present invention can be further configured such that a spiral agitator is provided in the neutralization tank and the coagulation tank in S2 and S3.

[0018] The method for treating acidic industrial wastewater provided by the present invention can be further configured such that the aeration in S8 uses an air compression aerator.

[0019] The method for treating acidic industrial wastewater provided by the present invention can be further configured such that the hollow fiber membrane of the S10 ultrafiltration adopts a bidirectional flow hollow fiber membrane.

[0020] The method for treating acidic industrial wastewater provided by the present invention can be further configured such that the inner wall of the wastewater pool in S1 is acid-resistant cement.

[0021] The advantages and benefits of the present invention are as follows: the acidic sewage treatment system of the present invention can remove most of the pollutants in industrial wastewater, and can effectively purify the sewage by adjusting the pH value of the acidic sewage and filtering the sewage, and then kill the organic matter in the sewage through aeration, and finally filter out the small molecular compounds in the sewage through ultrafiltration through the hollow fiber membrane, so that the acidic industrial sewage can be thoroughly purified, especially the acidic industrial sewage containing organic matter, and the required purification materials are very common and do not pollute the environment. DETAILED DESCRIPTION

[0022] The following is a further description of an embodiment of a method for treating acidic industrial wastewater according to the present invention.

[0023] A method for treating acidic industrial wastewater, characterized in that it comprises the following steps:

[0024] S1 filtration: filter the acidic sewage in the sewage pool to remove large particles of waste in the acidic sewage;

[0025] S2 Neutralization: Pump the filtered acidic sewage from the sewage pool into the neutralization tank, add an appropriate amount of sodium hydroxide, and adjust the pH to 9-9.6;

[0026] S3 coagulation: pump the acidic sewage from the neutralization tank into the coagulation tank, first add 10% basic aluminum chloride, react for 5-10 minutes, then add 0.1% polyacrylamide, react for 5-10 minutes, make the pH reach 7.2-7.85, and let it stand for 30 minutes after coagulation is completed;

[0027] S4 filtration: Use filter press to filter out the flocculent suspended matter after coagulation, and the pH reaches 6.8-7.4 after filtration;

[0028] S5 precipitation: precipitation is carried out in a sedimentation tank, and the precipitation time is 0.5-1 hour;

[0029] S6 PH adjustment: transfer the supernatant from the sedimentation tank to the treatment tank, add appropriate amount of sulfuric acid and ferrous sulfate heptahydrate, stir for about 10 minutes, and adjust the pH to 2.4;

[0030] S7 oxidation: add hydrogen peroxide and oxidize for 3-5 hours to make the pH reach 2.8-3.2;

[0031] S8 Aeration: Transfer the sewage to the aeration tank and blow air into the sewage to increase the oxygen content of the sewage;

[0032] S9 secondary processing: repeat the above steps S2-S5;

[0033] S10 ultrafiltration: uses hollow fiber membranes to filter out large particles in sewage;

[0034] S11 collection: discharge and collect the clean water after ultrafiltration.

[0035] The filtered impurities in the S10 ultrafiltration are collected to produce industrial alcohol to achieve waste utilization. The neutralization tank and coagulation tank in S2 and S3 are equipped with spiral agitators to accelerate the reaction and make the reaction more complete. The aeration in S8 adopts an air compression aerator to dissolve a large amount of oxygen in the sewage and eliminate anaerobic organic matter in the water. The hollow fiber membrane of the S10 ultrafiltration adopts a bidirectional flow hollow fiber membrane. The inner wall of the sewage pool in S1 is acid-resistant cement, which can be used for a long time and is protected from corrosion by acidic sewage.

[0036] The advantages and benefits of the present invention are as follows: the method for treating acidic industrial wastewater of the present invention can remove most of the pollutants in the industrial wastewater, and can effectively purify the wastewater by adjusting the pH value of the acidic wastewater and filtering the wastewater, and then kill the organic matter in the wastewater by aeration, and finally filter out the small molecular compounds in the wastewater by ultrafiltration through a hollow fiber membrane, so that the acidic industrial wastewater can be thoroughly purified, especially the acidic industrial wastewater containing organic matter, and the required purification materials are very common and do not pollute the environment.

[0037] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for treating acidic industrial wastewater, characterized in that: The following steps are included: S1 filtration: filter the acidic sewage in the sewage pool to remove large particles of waste in the acidic sewage; S2 Neutralization: Pump the filtered acidic sewage from the sewage pool into the neutralization tank, add an appropriate amount of sodium hydroxide, and adjust the pH to 9-9.6; S3 coagulation: pump the acidic sewage from the neutralization tank into the coagulation tank, first add 10% basic aluminum chloride, react for 5-10 minutes, then add 0.1% polyacrylamide, react for 5-10 minutes, make the pH reach 7.2-7.85, and let it stand for 30 minutes after coagulation is completed; S4 filtration: Use filter press to filter out the flocculent suspended matter after coagulation, and the pH reaches 6.8-7.4 after filtration; S5 precipitation: precipitation is carried out in a sedimentation tank, and the precipitation time is 0.5-1 hour; S6 PH adjustment: transfer the supernatant from the sedimentation tank to the treatment tank, add appropriate amount of sulfuric acid and ferrous sulfate heptahydrate, stir for about 10 minutes, and adjust the pH to 2.4; S7 oxidation: add hydrogen peroxide and oxidize for 3-5 hours to make the pH reach 2.8-3.2; S8 Aeration: Transfer the sewage to the aeration tank and blow air into the sewage to increase the oxygen content of the sewage; S9 secondary processing: repeat the above steps S2-S5; S10 ultrafiltration: uses hollow fiber membranes to filter out large particles in sewage; S11 collection: discharge and collect the clean water after ultrafiltration.

2. The method for treating acidic industrial wastewater according to claim 1, characterized in that: The filtered impurities in the S10 ultrafiltration are collected to produce industrial alcohol.

3. The method for treating acidic industrial wastewater according to claim 1, characterized in that: The neutralization tank and coagulation tank in S2 and S3 are provided with spiral agitators.

4. The method for treating acidic industrial wastewater according to claim 1, characterized in that: The aeration in S8 adopts an air compression aerator.

5. The method for treating acidic industrial wastewater according to claim 1, characterized in that: The hollow fiber membrane of the S10 ultrafiltration adopts a bidirectional flow hollow fiber membrane.

6. The method for treating acidic industrial wastewater according to claim 1, characterized in that: The inner wall of the sewage pool in S1 is acid-resistant cement.