Industrial wastewater purification method

Abstract

The invention relates to the field of industrial wastewater purification, in particular to an industrial wastewater purification method. The invention provides an industrial wastewater purification method, which comprises the following steps: adding heavy metal removers such as sodium sulfide, Friedel's salt and sodium phosphate dodecahydrate into industrial wastewater, reacting for a period of time, extracting, rectifying and filtering, adding dechlorinating agents such as sodium thiosulfate, calcium oxide and sodium metaaluminate into the filtrate, and filtering after the reaction is completed, thereby obtaining the up-to-standard discharge water body. Wherein ions react with the heavy metal removing agent and the chlorine removing agent, so that other compounds are prevented from being generated, and harmful elements in the industrial wastewater are effectively treated. The method is simple and easy to implement, the required treatment dosage is small, the treatment effect is remarkable, and the chlorine removal rate of the heavy metal and the chlorine element reaches 90% or above. And the treated wastewater can reach the discharge standard and can be used for industrial secondary utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment utilization, and specifically relates to a method for purifying industrial wastewater. Background Art

[0002] With the acceleration of the industrialization process, a large amount of industrial wastewater is discharged into water bodies, which contains a large number of toxic and harmful substances, seriously polluting water resources. This poses a serious threat to the water ecosystem and human health. The advancement of the urbanization process has led to a rapid increase in the urban population, and a large amount of domestic sewage is discharged into water bodies, which contains a large number of organic substances and microorganisms, polluting the water quality. This brings serious challenges to the sustainable utilization of water resources. Pesticides and fertilizers used in agricultural activities will enter water bodies with the washing of rainwater, causing eutrophication and deterioration of water quality. This has a negative impact on the balance of the water ecosystem and the sustainable utilization of water resources.

[0003] In recent years, the industrial wastewater treatment industry in China has developed rapidly. With the acceleration of the industrialization process, the discharge of industrial wastewater has put great pressure on the environment. To address this challenge, the state has introduced a series of policies, which have brought new development opportunities to the industrial wastewater treatment industry.

[0004] Therefore, finding a simple and easy-to-implement industrial wastewater purification method that requires less treatment dosage and has better treatment effects is the current key research object. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for purifying industrial wastewater, specifically as follows:

[0006] A method for purifying industrial wastewater, adding a heavy metal remover to the wastewater for reaction, and after the reaction is completed, performing extraction, membrane separation filtration and rectification treatment; finally, adding a dechlorinating agent to the treated water body, and after filtration, finally obtaining a water body that meets the discharge standard;

[0007] The heavy metal remover is one or more of sodium sulfide, Fred salt, and sodium phosphate dodecahydrate mixed in any proportion;

[0008] The dechlorinating agent is one or more of sodium thiosulfate, calcium oxide, and sodium metaaluminate mixed in any proportion.

[0009] Further, when the heavy metal remover is added to the wastewater for reaction, the reaction time is 30 minutes.

[0010] Further, the mass ratio of the industrial wastewater to the heavy metal remover is 1:0.03 - 0.06;

[0011] Furthermore, the molar ratio of chloride ions to dechlorinating agent in the industrial wastewater is 1:3-7.

[0012] Furthermore, the industrial wastewater purification method specifically comprises the following steps:

[0013] (1) adding a heavy metal remover to industrial wastewater and performing extraction after the reaction is completed;

[0014] (2) filtering and then rectifying the extracted supernatant;

[0015] (3) extracting the axe liquid obtained after the distillation treatment in step (2); filtering the raffinate at the lower layer after the extraction is completed;

[0016] (4) filtering the raffinate from (1) and (3), and subjecting the filtrate to membrane separation treatment;

[0017] (5) After the membrane separation treatment is completed, add the dechlorination agent, stir the reaction at a constant speed, and then filter it. The filtrate is the water body that meets the discharge standards.

[0018] Furthermore, the reaction time of each reaction is 30 minutes, and the industrial wastewater discharge complies with the GB1889-2024 and HJ1134-2020 emission standards.

[0019] Compared with the prior art, the technical effects created by the present invention are embodied in:

[0020] The present application provides a method for purifying industrial wastewater, wherein a heavy metal remover (sodium sulfide, Fred salt, sodium phosphate dodecahydrate) is added to the industrial wastewater, and after a period of reaction, a dechlorinating agent (sodium thiosulfate, calcium oxide, sodium aluminate) is added after extraction, distillation and filtration, and after the reaction is completed, the water body that meets the discharge standards is filtered. The ions react with the heavy metal remover and the dechlorinating agent to prevent them from forming other complexes, and the harmful elements in the industrial wastewater are effectively treated. The method of the present application is simple and easy to implement, the required treatment dosage is small, the treatment effect is significant, and the removal of chlorine by heavy metals and chlorine elements reaches more than 90%. The treated wastewater can meet the discharge standards and can be used for secondary industrial use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a simplified process flow diagram of this application. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further defined below in conjunction with specific implementation methods, but the scope of protection required is not limited to the description.

[0023] Example 1

[0024] (1) taking wastewater containing heavy metals and chloride ions, a heavy metal remover (Fred salt), and a dechlorinating agent (calcium oxide and sodium aluminate mixed (mixed in a ratio of 1:4)) for later use; adding the heavy metal remover into the wastewater at a ratio of 0.045:1 and stirring at a constant speed for 30 minutes, and performing extraction after the reaction is completed;

[0025] (2) extracting the material after the reaction in step (1), extracting the upper layer of the liquid and subjecting it to distillation treatment;

[0026] (3) extracting the axe liquid obtained after the distillation treatment in step (2); filtering the raffinate at the lower layer after the extraction is completed;

[0027] (4) filtering the raffinate from (1) and (3), and subjecting the filtrate to membrane separation treatment;

[0028] (5) After the membrane separation treatment is completed, a dechlorinating agent (a mixture of calcium oxide and sodium aluminate) is added at a molar ratio of chloride ions to dechlorinating agent of 1:3.4, and the mixture is stirred at a uniform speed for 30 minutes and then filtered to obtain a water body that meets the standards.

[0029] The contents of various elements in the water before purification are as follows: Zn, Pb, Cu, Ba, and Cl are 528.21 mg / L, 0.57 mg / L, 127.03 mg / L, 78.17 mg / L, and 27083.78 mg / L respectively; the contents of various elements after treatment are as follows: Zn, Pb, Cu, Ba, and Cl are 81.15 mg / L, 0.20 mg / L, 33.27 mg / L, 21.32 mg / L, and 2180.15 mg / L respectively.

[0030] Example 2

[0031] (1) taking wastewater containing heavy metals and chloride ions and a heavy metal remover (sodium sulfide) and a dechlorinating agent (calcium oxide and sodium aluminate mixed (mixed in a ratio of 1:4.5)) for later use; adding the heavy metal remover into the wastewater at a ratio of 0.05:1 and stirring at a constant speed for 30 minutes, and performing extraction after the reaction is completed;

[0032] (2) extracting the material after the reaction in step (1), extracting the upper layer of the liquid and subjecting it to distillation treatment;

[0033] (3) extracting the axe liquid obtained after the distillation treatment in step (2); filtering the raffinate at the lower layer after the extraction is completed;

[0034] (4) filtering the raffinate from (1) and (3), and subjecting the filtrate to membrane separation treatment;

[0035] (5) After the membrane separation treatment is completed, a dechlorinating agent (a mixture of calcium oxide and sodium aluminate) is added at a molar ratio of chloride ions to dechlorinating agent of 1:4, and the mixture is stirred at a uniform speed for 30 minutes and then filtered to obtain a water body that meets the standards.

[0036] The content of each element in the water before purification is as follows: Zn, Pb, Cu, Ba, Cl are 518.31mg / L, 0.49mg / L, 113.23mg / L, 72.75mg / L, 26531.13mg / L respectively; the content of each element after treatment is as follows: Zn, Pb, Cu, Ba, Cl are 78.75mg / L, 0.21mg / L, 31.17mg / L, 20.91mg / L, 4080.31mg / L respectively.

[0037] Example 3

[0038] (1) taking wastewater containing heavy metals and chloride ions, a heavy metal remover (Fred salt) and a dechlorinating agent (sodium thiosulfate) for later use; adding the heavy metal remover into the wastewater at a ratio of 0.06:1 and stirring at a constant speed for 30 minutes, and performing extraction after the reaction is completed;

[0039] (2) extracting the material after the reaction in step (1), extracting the upper layer of the liquid and subjecting it to distillation treatment;

[0040] (3) extracting the axe liquid obtained after the distillation treatment in step (2); filtering the raffinate at the lower layer after the extraction is completed;

[0041] (4) filtering the raffinate from (1) and (3), and subjecting the filtrate to membrane separation treatment;

[0042] (5) After the membrane separation treatment is completed, a dechlorinating agent (sodium thiosulfate) is added at a molar ratio of chloride ions to dechlorinating agent of 1:5, and the mixture is stirred at a uniform speed for 30 minutes before filtering to obtain water that meets the standards.

[0043] The contents of various elements in the water before purification are as follows: Zn, Pb, Cu, Ba, and Cl are 503.27 mg / L, 0.61 mg / L, 131.32 mg / L, 71.79 mg / L, and 27708.15 mg / L respectively; the contents of various elements after treatment are as follows: Zn, Pb, Cu, Ba, and Cl are 71.58 mg / L, 0.20 mg / L, 32.83 mg / L, 23.21 mg / L, and 3242.14 mg / L respectively.

[0044] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the technical solution of the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A method for purifying industrial wastewater, characterized in that: Add heavy metal remover to wastewater for reaction, and then perform extraction, membrane separation, filtration and distillation after the reaction is completed; finally, add dechlorinator to the treated water, and after filtration, finally obtain water that meets the discharge standards; The heavy metal remover is one or more of sodium sulfide, Fred salt, and sodium phosphate dodecahydrate mixed in any proportion; The dechlorinating agent is one or more of sodium thiosulfate, calcium oxide and sodium aluminate mixed in any proportion.

2. The industrial wastewater purification method according to claim 1, characterized in that: The heavy metal remover is added into the wastewater to react, and the reaction time is 30 minutes.

3. The industrial wastewater purification method according to claim 1, characterized in that: The mass ratio of the industrial wastewater to the heavy metal remover is 1:0.03-0.

06.

4. The industrial wastewater purification method according to claim 1, characterized in that: The molar ratio of chloride ions to dechlorinating agent in the industrial wastewater is 1:3-7.

5. The industrial wastewater purification method according to claim 1, characterized in that: The specific steps include: (1) adding a heavy metal remover to industrial wastewater and performing extraction after the reaction is completed; (2) filtering and then rectifying the extracted supernatant; (3) extracting the axe liquid obtained after the distillation treatment in step (2); filtering the raffinate at the lower layer after the extraction is completed; (4) filtering the raffinate from (1) and (3), and subjecting the filtrate to membrane separation treatment; (5) After the membrane separation treatment is completed, add the dechlorination agent, stir the reaction at a constant speed, and then filter. The filtrate is the water body that meets the discharge standards.

6. The industrial wastewater purification method according to claim 5, characterized in that: The reaction time of each reaction is 30 min; the discharge of industrial wastewater complies with the emission standards of GB1889-2024 and HJ1134-2020.

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