A full membrane zero-discharge treatment process for complex copper wastewater

Abstract

The present application relates to the technical field of wastewater treatment, and specifically discloses a full membrane method zero-emission treatment process for complex copper wastewater. A full membrane method zero-emission treatment process for complex copper wastewater, comprising the following steps: pH adjustment: adjusting the pH of the wastewater to 7.5-8.0; tubular membrane pretreatment: adding an adsorbent to the wastewater to obtain a mixed solution, and then filtering with a tubular membrane to remove the filter residue to obtain crude water; wherein the weight ratio of the adsorbent in the mixed solution is 100-200ppm; RO reverse osmosis desalination: using an RO membrane to desalinate the crude water to obtain discharge water. The wastewater treatment process in this application is simple to operate, and no complex breaking agent needs to be added for complex breaking reaction, thereby improving the treatment effect of the wastewater.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to a full-membrane zero-emission treatment process for complex copper wastewater. Background Art

[0002] The complex copper wastewater contains a large amount of complex copper, including copper-chloro complex, EDTA-copper ammonium complex and copper-ammonia complex. The complex copper wastewater mainly comes from printed circuit board wastewater, electroplating wastewater and dye wastewater. Usually, when treating complex copper wastewater, it is difficult to remove copper ion pollutants by normal treatment. It is necessary to first perform complex breaking treatment and then perform chemical precipitation to remove copper ions in the complex copper wastewater. Among them, the treatment processes for complex breaking treatment mainly include Fenton oxidation method, sodium sulfide method, iron-carbon micro-electrolysis method, ferrous sulfate method, ion exchange method and the like. Complex breaking treatment requires the addition of complex breaking agents, which in turn brings new ions, resulting in cumbersome wastewater treatment process and affecting the treatment effect of wastewater. Summary of the invention

[0003] In order to improve the treatment effect of wastewater, the present application provides a full membrane zero-emission treatment process for complex copper wastewater.

[0004] The present application provides a full membrane zero-discharge treatment process for complex copper wastewater, which adopts the following technical solution:

[0005] A full membrane zero-discharge treatment process for complex copper wastewater comprises the following steps:

[0006] pH adjustment: adjust the pH of wastewater to 7.5-8.0;

[0007] Tubular membrane pretreatment: Add adsorbent to wastewater to obtain a mixed solution, then filter using tubular membrane to remove filter residue to obtain crude water; the weight ratio of adsorbent in the mixed solution is 100-200ppm;

[0008] RO reverse osmosis desalination: Use RO membrane to desalinate raw water to obtain discharge water.

[0009] By adopting the above technical scheme, under the condition of pH=7.5-8.0, an adsorbent with a weight ratio of 100-200ppm is added to the wastewater, and the adsorbent adsorbs small molecular organic matter in the wastewater, and then uses tubular membrane filtration to remove small molecular organic matter, and finally uses RO membrane for desalination, separates the solvent, removes macromolecular organic matter, thereby completing the treatment of the wastewater. The wastewater treatment process in the present application is simple to operate, and does not need to add any complex breaking agent for complex breaking reaction, thereby improving the treatment effect of the wastewater.

[0010] In a specific feasible implementation scheme, in the RO reverse osmosis desalination step: firstly, four Dow anti-pollution membranes are used to desalinate the crude water to obtain a primary permeate and a concentrated solution, and then three Dow low-pressure membranes are used to perform a secondary desalination on the primary permeate to obtain a secondary permeate, and the secondary permeate is sterilized by UV to obtain discharge water.

[0011] By adopting the above technical solution, the present application performs two desalination treatments, and limits the RO membranes specifically used for the two desalinations, and then performs UV sterilization, thereby further improving the treatment effect of the wastewater.

[0012] In a specific embodiment, in the RO reverse osmosis desalination step: the concentrated liquid is added to the MVR evaporator for evaporation and concentration to obtain a condensate, and the condensate is again subjected to tubular membrane pretreatment and RO reverse osmosis desalination to obtain discharge water.

[0013] By adopting the above technical solution, the concentrated liquid obtained by the primary desalination is evaporated and concentrated, and then the obtained condensate is subjected to wastewater treatment again, thereby increasing the output of discharged water.

[0014] In a specific embodiment, the raw materials of the adsorbent include the following components: activated carbon, dopamine, a silane coupling agent, and polyaniline.

[0015] By adopting the above technical scheme, the activated carbon has good adsorption performance and can effectively adsorb small molecular organic matter in the wastewater; the amine group and imine group in the polyaniline molecular chain can adsorb heavy metal ions in the wastewater, but the particle size of polyaniline is small, and a large pressure drop will be generated during the adsorption process, which will affect the wastewater treatment; dopamine forms an adhesive film with an adhesion effect on the surface of the activated carbon, so that the polyaniline is loaded on the activated carbon, thereby reducing the pressure drop. In addition, the silane coupling agent introduces hydrophilic groups to the polyaniline, and dopamine also brings hydrophilic groups while forming an adhesive film on the surface of the activated carbon, so that the prepared adsorbent has good hydrophilic properties, so it can be evenly dispersed in the wastewater for adsorption, thereby improving the adsorption effect of the adsorbent.

[0016] In a specific embodiment, the method for preparing the adsorbent comprises the following steps:

[0017] Modification: prepare an ethanol aqueous solution, add a silane coupling agent to the ethanol aqueous solution, stir evenly, add polyaniline at 70-90°C, stir to react, filter, and dry to obtain modified polyaniline;

[0018] Compounding: dopamine is added to a buffer solution to obtain a dopamine solution, the pH is adjusted to 8-9, activated carbon is added to the dopamine solution for immersion, filtered, and dried to obtain modified activated carbon; modified polyaniline is added to water, stirred evenly, and then the modified activated carbon is added, slowly stirred, filtered, and dried to obtain an adsorbent.

[0019] By adopting the above technical scheme, polyaniline is first modified with a silane coupling agent to introduce hydrophilic groups on the surface of polyaniline, and then activated carbon is modified with dopamine so that dopamine forms an adhesive film on the surface of activated carbon. Then, polyaniline is loaded on the activated carbon to obtain an adsorbent with better adsorption effect.

[0020] In a specific embodiment, in the modification step, the weight ratio of the silane coupling agent to the polyaniline is 1:(60-70), and the silane coupling agent includes γ-glycidyloxypropyltrimethoxysilane.

[0021] By adopting the above technical solution, the present application further defines the ratio of the silane coupling agent to the polyaniline and the type of the silane coupling agent, thereby improving the modification effect of the polyaniline.

[0022] In a specific embodiment, in the modification step, the mass fraction of dopamine in the dopamine solution is 0.1-0.5 g / mL.

[0023] By adopting the above technical solution, the mass fraction of dopamine in the dopamine solution is further limited in the present application, which is beneficial to the formation of an adhesive film on the surface of the activated carbon.

[0024] In a specific embodiment, in the compounding step, the weight ratio of the modified activated carbon to the modified polyaniline is 1:(4-8).

[0025] By adopting the above technical solution, the present application further defines the ratio of modified activated carbon and modified polyaniline, so that the modified polyaniline is better loaded on the modified activated carbon, thereby improving the adsorption effect of the adsorbent.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] 1. In this application, an adsorbent with a weight ratio of 100-200ppm is added to the wastewater, and the adsorbent adsorbs small molecular organic matter in the wastewater, and then uses tubular membrane filtration to remove small molecular organic matter, and finally uses RO membrane for desalination, separates the solvent, removes large molecular organic matter, and thus completes the treatment of the wastewater. The wastewater treatment process in this application is simple to operate, and does not require the addition of any complex breaking agent for complex breaking reaction, thereby improving the treatment effect of the wastewater;

[0028] 2. In this application, two desalination treatments are performed, and the RO membranes used for the two desalinations are specified, followed by UV sterilization, thereby further improving the wastewater treatment effect;

[0029] 3. The adsorbent in the present application, the activated carbon in the adsorbent has good adsorption performance, can effectively adsorb small molecular organic matter in the wastewater, the amine group and imine group in the polyaniline molecular chain can adsorb heavy metal ions in the wastewater, and can also be evenly dispersed in the wastewater for adsorption, thereby improving the adsorption effect of the adsorbent;

[0030] 4. The preparation method of the adsorbent in the present application is to first modify polyaniline with a silane coupling agent, introduce hydrophilic groups on the surface of polyaniline, and then modify activated carbon with dopamine so that dopamine forms an adhesive film on the surface of activated carbon. Then, polyaniline is loaded on the activated carbon to obtain an adsorbent with better adsorption effect. DETAILED DESCRIPTION

[0031] The present application is further described in detail below with reference to the embodiments.

[0032] All raw materials in the examples can be obtained from the market, among which the model of Dow anti-pollution membrane is BW30FR-400 / 34; the model of Dow low-pressure membrane is BW30-400; the activated carbon is powdered activated carbon, CAS No.: 64365-11-3; and the CAS No. of polyaniline is 5612-44-2.

[0033] Preparation Example

[0034] Preparation Example 1

[0035] Preparation Example 1 provides a method for preparing an adsorbent, comprising the following steps:

[0036] Modification: prepare an ethanol aqueous solution, add a silane coupling agent to the ethanol aqueous solution, stir evenly, add polyaniline at 80°C, stir and react for 24 hours, filter, and vacuum dry the filter residue at 120°C to obtain modified polyaniline; wherein the volume ratio of ethanol to water in the ethanol aqueous solution is 9:1; the volume ratio of the silane coupling agent to the ethanol aqueous solution is 1:4; the weight ratio of the silane coupling agent to the polyaniline is 1:60, and the silane coupling agent is γ-glycidyloxypropyltrimethoxysilane;

[0037] Compounding: Add tris(hydroxymethyl)aminomethane to water and stir evenly to obtain a buffer solution; wherein the weight ratio of tris(hydroxymethyl)aminomethane to water is 1:65; add dopamine to the buffer solution and stir evenly to obtain a dopamine solution; adjust the pH value of the dopamine solution to 8 using 37% concentrated hydrochloric acid; add activated carbon to the dopamine solution and immerse for 12 hours, filter, and dry the filter residue at 60°C to obtain modified activated carbon; wherein the mass fraction of dopamine in the dopamine solution is 0.1 g / mL; add modified polyaniline to water and stir evenly to make it fully dispersed, then add modified activated carbon, stir slowly for 30 minutes, filter, and dry the filter residue at 60°C to obtain an adsorbent. wherein the weight ratio of modified activated carbon to modified polyaniline is 1:4.

[0038] Preparation Example 2

[0039] The difference between Preparation Example 2 and Preparation Example 1 is that the weight ratio of the silane coupling agent to the polyaniline is 1:65, and the remaining steps are consistent with Example 1.

[0040] Preparation Example 3

[0041] The difference between Preparation Example 3 and Preparation Example 1 is that the weight ratio of the silane coupling agent to the polyaniline is 1:70, and the remaining steps are consistent with Example 1.

[0042] Preparation Example 4

[0043] The difference between Preparation Example 4 and Preparation Example 2 is that the mass fraction of dopamine in the dopamine solution is 0.3 g / mL, and the remaining steps are consistent with Example 2.

[0044] Preparation Example 5

[0045] The difference between Preparation Example 5 and Preparation Example 2 is that the mass fraction of dopamine in the dopamine solution is 0.5 g / mL, and the remaining steps are consistent with Example 2.

[0046] Preparation Example 6

[0047] The difference between Preparation Example 6 and Preparation Example 4 is that the weight ratio of modified activated carbon to modified polyaniline is 1:6, and the remaining steps are consistent with Example 4.

[0048] Preparation Example 7

[0049] The difference between Preparation Example 7 and Preparation Example 4 is that the weight ratio of modified activated carbon to modified polyaniline is 1:8, and the remaining steps are consistent with Example 4.

[0050] Example

[0051] Example 1

[0052] Example 1 provides a full membrane zero-discharge treatment process for complex copper wastewater, comprising the following steps:

[0053] Adjust pH: First, homogenize the wastewater, and then adjust the pH of the wastewater to 7.5;

[0054] Tubular membrane pretreatment: Add the wastewater to a circulation tank, then add the adsorbent in Preparation Example 1 to the wastewater to obtain a mixed solution, and then use a tubular membrane to filter, remove the filter residue, and obtain crude water; wherein the weight ratio of the adsorbent in the mixed solution is 100ppm; RO reverse osmosis desalination: first use four Dow anti-pollution membranes to desalinate the crude water to obtain a primary permeate and a concentrated solution, and then use three Dow low-pressure membranes to perform secondary desalination on the primary permeate to obtain a secondary permeate, and perform UV sterilization on the secondary permeate to obtain discharge water; the concentrated solution is added to the MVR evaporator for evaporation and concentration to obtain a condensate, and the condensate is added to the circulation tank for further treatment.

[0055] Example 2

[0056] The difference between Example 2 and Example 1 is that in the pH adjustment step, the pH of the wastewater is adjusted to 7.8, and the remaining steps are consistent with Example 1.

[0057] Example 3

[0058] The difference between Example 3 and Example 1 is that in the pH adjustment step, the pH of the wastewater is adjusted to 8.0, and the remaining steps are consistent with Example 1.

[0059] Example 4

[0060] The difference between Example 4 and Example 2 is that in the step of tube membrane pretreatment, the weight ratio of the adsorbent in the mixed liquid is 150 ppm, and the remaining steps are consistent with Example 2.

[0061] Example 5

[0062] The difference between Example 5 and Example 2 is that in the step of tube membrane pretreatment, the weight ratio of the adsorbent in the mixed liquid is 200 ppm, and the remaining steps are consistent with Example 2.

[0063] Example 6

[0064] The difference between Example 6 and Example 4 is that the adsorbent is replaced by an equal amount of activated carbon powder, and the remaining steps are consistent with Example 4.

[0065] Examples 7-12

[0066] The difference between Examples 7-12 and Example 4 is that the adsorbents are selected differently, see Table 1 for details.

[0067] Table 1 Selection of adsorbent

[0068] sample Selection of adsorbent Example 7 Preparation Example 2 Example 8 Preparation Example 3 Example 9 Preparation Example 4 Example 10 Preparation Example 5 Embodiment 11 Preparation Example 6 Example 12 Preparation Example 7

[0069] Comparative Example

[0070] Comparative Example 1

[0071] The difference between Comparative Example 1 and Example 1 is that in the pH adjustment step, the pH of the wastewater is adjusted to 7.0, and the remaining steps are consistent with Example 1.

[0072] Comparative Example 2

[0073] The difference between Comparative Example 2 and Example 1 is that in the pH adjustment step, the pH of the wastewater is adjusted to 8.5, and the remaining steps are consistent with Example 1.

[0074] Comparative Example 3

[0075] The difference between Comparative Example 3 and Example 2 is that in the step of tube membrane pretreatment, the weight ratio of the adsorbent in the mixed liquid is 50 ppm, and the remaining steps are consistent with Example 2.

[0076] Comparative Example 4

[0077] The difference between Comparative Example 4 and Example 2 is that in the step of tube membrane pretreatment, the weight ratio of the adsorbent in the mixed liquid is 250 ppm, and the remaining steps are consistent with Example 2.

[0078] Performance testing

[0079] The discharged water in Examples 1-6 and Comparative Examples 1-4 was tested to determine the contents of metal ions, COD and EC in the discharged water; the raw water in Examples 4 and Examples 7-12 was tested to determine the contents of metal ions, COD and EC in the raw water.

[0080] Table 2 Performance test results of discharged water

[0081]

[0082] Combining Examples 1-3 and Comparative Examples 1-2, the wastewater treatment effect in Examples 1-3 is better. It can be seen that adjusting the wastewater to 7.5-8.0 before tubular membrane pretreatment is beneficial to subsequent wastewater treatment, thereby improving the wastewater treatment effect.

[0083] In combination with Example 2, Examples 4-5 and Comparative Examples 3-4, the treatment effect of the wastewater in Example 2 and Example 4-5 is better. It can be seen that when the amount of adsorbent added during tubular membrane pretreatment is 100-200ppm, the adsorption effect on small molecular organic matter and heavy metal ions in the wastewater is better, thereby improving the treatment effect of the wastewater.

[0084] Combining Example 4 and Example 6, the wastewater treatment effect in Example 4 is better. It can be seen that the composite adsorbent composed of activated carbon and polyaniline can not only adsorb small molecular organic matter in the wastewater, but also adsorb heavy metal ions in the wastewater, thereby improving the adsorption effect of the adsorbent, thereby improving the final wastewater treatment effect.

[0085] Table 3 Performance test results of crude water

[0086]

[0087] In combination with Example 4, Example 7 and Example 8, the treatment effect of crude water in Example 7 is the best, and thus the adsorbent in Preparation Example 2 has the best adsorption effect. It can be seen that when preparing the adsorbent, the ratio of polyaniline to the silane coupling agent is increased, and the modification effect of polyaniline reaches a peak and then shows a downward trend, so that the adsorption effect of the adsorbent shows a trend of first increasing and then decreasing.

[0088] In combination with Example 7, Example 9 and Example 10, the treatment effect of crude water in Example 9 is the best, and thus the adsorption effect of the adsorbent in Preparation Example 4 is the best. It can be seen that when preparing the adsorbent, the mass fraction of dopamine in the dopamine solution is increased, and the modification effect of the activated carbon reaches a peak and then shows a downward trend, so that the adsorption effect of the adsorbent shows a trend of first increasing and then decreasing.

[0089] In combination with Example 9, Example 11 and Example 12, the treatment effect of crude water in Example 11 is the best, and thus the adsorbent in Preparation Example 6 has the best adsorption effect. It can be seen that when preparing the adsorbent, increasing the ratio of modified polyaniline to modified activated carbon, the adsorption effect of the adsorbent shows a trend of first increasing and then decreasing.

[0090] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A full membrane zero-discharge treatment process for complex copper wastewater, characterized in that: The following steps are involved: pH adjustment: adjust the pH of wastewater to 7.5-8.0; Tubular membrane pretreatment: add adsorbent to wastewater to obtain a mixed solution, then use tubular membrane to filter, remove the filter residue, and obtain crude water; The weight ratio of the adsorbent in the mixed solution is 100-200 ppm; the raw materials of the adsorbent include the following components: activated carbon, dopamine, silane coupling agent, polyaniline; the preparation method of the adsorbent includes the following steps: Modification: prepare an ethanol aqueous solution, add a silane coupling agent to the ethanol aqueous solution, stir evenly, add polyaniline at 70-90°C, stir to react, filter, and dry to obtain modified polyaniline; Compounding: Add dopamine to a buffer solution to obtain a dopamine solution, adjust the pH to 8-9, add activated carbon to the dopamine solution for immersion, filter, and dry to obtain modified activated carbon; add modified polyaniline to water, stir evenly, then add the modified activated carbon, slowly stir, filter, and dry to obtain an adsorbent; RO reverse osmosis desalination: Use RO membrane to desalinate raw water to obtain discharge water.

2. The full membrane zero-discharge treatment process for complex copper wastewater according to claim 1, characterized in that: In the RO reverse osmosis desalination step: firstly, four Dow anti-pollution membranes are used to desalinate the crude water to obtain a primary permeate and a concentrated solution, and then three Dow low-pressure membranes are used to perform a secondary desalination on the primary permeate to obtain a secondary permeate, and the secondary permeate is sterilized by UV to obtain discharge water.

3. The full membrane zero-discharge treatment process for complex copper wastewater according to claim 2, characterized in that: In the RO reverse osmosis desalination step: the concentrated liquid is added to the MVR evaporator for evaporation and concentration to obtain a condensate, and the condensate is subjected to tube membrane pretreatment and RO reverse osmosis desalination again to obtain discharge water.

4. The full membrane zero-discharge treatment process for complex copper wastewater according to claim 1, characterized in that: In the modification step, the weight ratio of the silane coupling agent to the polyaniline is 1:(60-70), and the silane coupling agent includes γ-glycidyloxypropyltrimethoxysilane.

5. The full membrane zero-discharge treatment process for complex copper wastewater according to claim 1, characterized in that: In the modification step, the mass fraction of dopamine in the dopamine solution is 0.1-0.5 g / mL.

6. The full membrane zero-discharge treatment process for complex copper wastewater according to claim 1, characterized in that: In the compounding step, the weight ratio of the modified activated carbon to the modified polyaniline is 1:(4-8).

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