A process for treating LED chip wastewater using composite materials

Abstract

The present invention relates to a process for treating LED chip wastewater using a composite material, and belongs to the technical field of chip wastewater treatment. The present invention uses a composite material to treat LED chip wastewater. Chitosan, vermiculite, activated carbon, and nano-alumina in the composite material adsorb heavy metal ions, organic pollutants, and suspended matter in the wastewater onto the surface or pores of the material through physical adsorption and chemical adsorption. The present invention first prepares a chitosan-vermiculite composite, uses glutaraldehyde as a cross-linking agent, forms a strong chemical bond between chitosan and vermiculite, improves the stability and mechanical strength of the chitosan-vermiculite composite, and optimizes the pore structure of the chitosan-vermiculite composite. Then, activated carbon, nano-alumina, and nano-iron oxide are added to remove organic pollutants, chromaticity, and heavy metal ions in the wastewater while promoting the degradation of organic pollutants. The present invention achieves efficient purification of wastewater through the comprehensive application of multiple means such as physical, chemical, and biological methods.

Description

Technical Field

[0001] The invention belongs to the technical field of chip wastewater treatment and relates to a process for treating LED chip wastewater using a composite material. Background Art

[0002] A light-emitting diode (LED) is a semiconductor device that converts electrical energy into light. With advancements in LED technology, it is finding increasing application in both lighting and display applications as a new, high-efficiency solid-state light source. Compared to existing lighting equipment, LED lighting offers advantages such as energy conservation and reduced power consumption, safety and environmental protection, long lifespan, robust structure, and space-saving installation. However, due to the high water consumption per unit area of ​​LED products, the substantial increase in production volume is bound to result in significant pollutant emissions during the production process. Consequently, industrial wastewater discharge has also seen a dramatic increase. As the industry continues to grow, effectively managing this wastewater has become a major challenge for the industry and its businesses.

[0003] As an emerging high-tech industry, the rapid development of the LED industry inevitably generates large amounts of wastewater pollutants. Effectively controlling and treating this wastewater has become a major challenge for the industry. Due to varying production processes, as well as differences in raw materials and reagents used, LED industry wastewater is diverse and of relatively complex quality. Summary of the Invention

[0004] The purpose of the present invention is to provide a process for treating LED chip wastewater using a composite material, which has the characteristics of high adsorption efficiency.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A process for treating LED chip wastewater using a composite material, the specific process is as follows:

[0007] S1: The LED chip wastewater is first coarsely filtered through a grid to remove large particles of impurities and sediment in the wastewater;

[0008] S2: Collect the wastewater after coarse filtration and pass it into regulating tank 1, add 10% alkali solution by mass into regulating tank 1; then pass it into regulating tank 2, add 10% acid solution by mass into regulating tank 2, collect the wastewater after conditioning, add the composite material into the wastewater, and stir for 0.5h;

[0009] S3: filtering the wastewater treated in S2 through an ultrafiltration membrane to obtain a clear liquid;

[0010] S4: The clear liquid obtained in S3 is concentrated by a reverse osmosis membrane to a concentration of 2.5-6 times;

[0011] S5: The concentrated supernatant from S4 is passed through an ion exchange resin;

[0012] S6: Pass ozone into the clear liquid obtained in S5 for sterilization, and discharge the treated waste liquid;

[0013] The preparation method of the composite material in S2 is as follows:

[0014] S2.1: Dissolve chitosan in acetic acid solution and stir at 150 r / min for 0.5 h to prepare a mixed solution A with a mass fraction of 30-50%;

[0015] S2.2: Grind the vermiculite in a ball mill at 400 rpm for 0.5 h to obtain vermiculite powder with a particle size of 150 mesh;

[0016] S2.3: Adding vermiculite powder to mixed solution A, wherein the mass ratio of vermiculite to chitosan is 2:3, and adding 0.5-2 wt% glutaraldehyde. Slowly heating the mixture from room temperature to 60°C and stirring for 2 h to obtain a solid-liquid mixture B. Filtering the solid-liquid mixture B, washing the filter residue with deionized water, and drying at 80°C for 12 h to obtain a mixture C.

[0017] S2.4: Mixture C, activated carbon, nano-alumina, and nano-ferric oxide in a mass ratio of 2:1:1:1, and grind them in a ball mill at 400 rpm for 0.5 h to obtain mixture D;

[0018] S2.5: Press the mixture D into a sheet at room temperature and a pressure of 10 MPa to obtain the composite material.

[0019] Furthermore, the alkali solution in S2 is one or more of ammonia water, sodium hydroxide solution, and potassium hydroxide solution.

[0020] Furthermore, the acid solution in S2 is one or more of hydrochloric acid solution and sulfuric acid solution.

[0021] Furthermore, the ultrafiltration membrane in S3 is a ceramic membrane, and the pore size of the ceramic membrane is 4 to 10 nm.

[0022] Furthermore, the ion exchange resin in S5 is a cation exchange resin.

[0023] Furthermore, the ozone flow rate in S6 is 20 m / s, and the sterilization time is 1 hour.

[0024] Furthermore, the volume fraction of the acetic acid solution in S2.1 is 2%.

[0025] Furthermore, the heating rate of slowly heating from room temperature to 60° C. in S2.3 is 2° C. / min.

[0026] Furthermore, the particle size of the mixture D in S2.4 is 150 mesh.

[0027] The present invention prepares a composite material that combines multiple materials such as chitosan, vermiculite, activated carbon, nano-alumina and nano-ferric oxide. The composite material has a higher adsorption capacity and a faster adsorption rate. The composite material can simultaneously treat multiple pollutants in wastewater, including heavy metal ions, organic pollutants and suspended matter. The material itself is non-toxic and harmless, and is easy to recycle and treat, and will not cause secondary pollution to the environment.

[0028] Chitosan is a natural high-molecular flocculant with a large number of hydroxyl and amino groups distributed on its molecular chain. These groups can form stable complexes or chelates with heavy metal ions (such as zinc, lead, chromium, etc.) in wastewater, thereby removing them from the wastewater. Chitosan can also adsorb organic pollutants in wastewater through hydrogen bonding, ion exchange, etc.; In addition, chitosan carries a positive charge in the solution and can undergo electrical neutralization with negatively charged particles (such as suspended matter, colloids, etc.) in the wastewater, causing them to aggregate into larger flocs, which are convenient for subsequent precipitation and separation.

[0029] After grinding, vermiculite has a large specific surface area and pore structure, which can provide abundant adsorption sites and enhance the adsorption capacity of the composite material. At the same time, the layered structure of vermiculite also has a certain filtering effect, which can intercept suspended matter and colloidal particles in wastewater. After vermiculite and chitosan are compounded, the two produce a synergistic effect in adsorption performance. Vermiculite increases the adsorption area of ​​chitosan and improves its adsorption efficiency; while chitosan further enhances the adsorption performance of the composite material through its adsorption mechanism.

[0030] Therefore, the present invention first prepares a chitosan-vermiculite composite. Glutaraldehyde is added as a cross-linking agent during the preparation process to form a stronger chemical bond between the chitosan and vermiculite, thereby improving the stability and mechanical strength of the composite. Furthermore, the cross-linking effect helps optimize the composite's pore structure, further enhancing its adsorption properties.

[0031] Activated carbon, nano-alumina and nano-iron oxide are also added to the composite material of the present invention. The activated carbon removes organic pollutants and color in wastewater through physical adsorption and chemical adsorption; the nano-alumina has a high specific surface area and surface activity and has an excellent adsorption effect on heavy metal ions; the nano-iron oxide has a certain catalytic effect and can promote the degradation of organic pollutants.

[0032] Chitosan-vermiculite complexes and activated carbon can work together to remove organic matter and heavy metal ions from wastewater through adsorption. Chitosan-vermiculite complexes achieve adsorption through chemical bonds or electrostatic interactions with heavy metal ions and organic matter in wastewater via surface functional groups such as amino and hydroxyl groups. Activated carbon, on the other hand, utilizes its porous structure and high specific surface area to capture pollutants in wastewater through physical adsorption. The combined use of these two agents can expand the adsorption range and improve adsorption efficiency, creating a synergistic adsorption mechanism. This synergistic effect enhances adsorption and improves wastewater treatment efficiency. Nano-alumina and nano-iron oxide act as catalysts to promote oxidation reactions in wastewater. Nano-alumina catalyzes the oxidation of organic matter in wastewater, while nano-iron oxide accelerates the oxidation reaction. When present simultaneously, these two agents promote each other, forming a synergistic catalytic oxidation mechanism that improves wastewater treatment efficiency. During the catalytic oxidation process, microorganisms adsorbed on the activated carbon surface utilize the oxidants produced by the nano-alumina and nano-iron oxide to further degrade the organic matter, thereby achieving a combined biodegradation and catalytic oxidation effect. At the same time, they can also be combined with activated carbon and chitosan vermiculite complexes to remove organic matter in wastewater through a combination of catalytic oxidation and adsorption. Nano-alumina and nano-iron oxide remove heavy metal ions by generating insoluble precipitates. At the same time, chitosan vermiculite complexes and activated carbon participate in this process and further remove heavy metal pollution in wastewater through adsorption.

[0033] In the present invention, large suspended matter, such as solid waste and debris, is first removed from the wastewater through grid filtration to prevent clogging of subsequent treatment equipment. The water volume and water quality of the wastewater are then adjusted through two regulating tanks to make the subsequent treatment process more stable. Composite materials are then added to remove suspended matter, colloidal matter, heavy metal ions and organic pollutants in the wastewater through adsorption. After the adsorption is completed, suspended matter, bacteria, colloidal matter and some large molecular organic matter in the wastewater are removed through ultrafiltration. Impurities such as inorganic salts, organic matter and viruses in the wastewater are removed through deep desalination through reverse osmosis. Residual pollutants such as heavy metal ions in the wastewater are then removed through cation exchange resin. Finally, ozone is used for sterilization, and the treated wastewater that meets the standards is discharged.

[0034] Beneficial effects of the present invention:

[0035] The present invention uses a composite material to treat LED chip wastewater. Chitosan, vermiculite, activated carbon and nano-alumina in the composite material adsorb heavy metal ions, organic pollutants and suspended matter in the wastewater onto the surface or pores of the material through physical adsorption and chemical adsorption. The present invention first prepares a chitosan-vermiculite composite, and then adds glutaraldehyde as a cross-linking agent to form a stronger chemical bond between the chitosan and the vermiculite, thereby improving the stability and mechanical strength of the chitosan-vermiculite composite. The cross-linking effect also helps to optimize the pore structure of the chitosan-vermiculite composite, further improving its adsorption performance. Then, activated carbon, nano-alumina and nano-ferric oxide are added to remove organic pollutants, color and heavy metal ions in the wastewater while promoting the degradation of organic pollutants.

[0036] The present invention realizes efficient purification, recycling and reuse of wastewater and biosafety assurance through comprehensive application of physical, chemical and biological means. DETAILED DESCRIPTION

[0037] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0038] Example 1

[0039] S1: The LED chip wastewater is first coarsely filtered through a grid to remove large particles of impurities and sediment in the wastewater;

[0040] S2: Collect the wastewater after coarse filtration and pass it into regulating tank 1, into which 10% ammonia water is added; then pass it into regulating tank 2, into which 10% hydrochloric acid solution is added, collect the wastewater after conditioning, add the composite material to the wastewater, and stir for 0.5h;

[0041] S3: The wastewater treated in S2 is filtered through an ultrafiltration membrane, which is a ceramic membrane with a pore size of 4 nm, to obtain a clear liquid;

[0042] S4: The clear liquid obtained in S3 is concentrated by a reverse osmosis membrane to a concentration of 5 times;

[0043] S5: The concentrated supernatant from S4 is passed through a cation exchange resin;

[0044] S6: Pass ozone into the clear liquid obtained in S5 for sterilization. The ozone flow rate is 20 m / s and the sterilization time is 1 hour. The treated waste liquid is discharged.

[0045] The preparation method of the composite material in S2 is as follows:

[0046] S2.1: Dissolve chitosan in acetic acid solution with a volume fraction of 2% and stir at 150 r / min for 0.5 h to prepare a mixed solution A with a mass fraction of 40%;

[0047] S2.2: Grind the vermiculite in a ball mill at 400 rpm for 0.5 h to obtain vermiculite powder with a particle size of 150 mesh;

[0048] S2.3: Add vermiculite powder to mixed solution A, wherein the mass ratio of vermiculite to chitosan is 2:3, and add 1 wt% glutaraldehyde. Slowly heat the mixture from room temperature to 60°C and stir for 2 h at a heating rate of 2°C / min to obtain a solid-liquid mixture B. Filter the solid-liquid mixture B, wash the filter residue with deionized water, and dry it at 80°C for 12 h to obtain a mixture C.

[0049] S2.4: Mixture C, activated carbon, nano-alumina, and nano-ferric oxide in a mass ratio of 2:1:1:1 were mixed and ground in a ball mill at 400 rpm for 0.5 h to obtain mixture D. The particle size of mixture D was 150 mesh.

[0050] S2.5: Press the mixture D into a sheet at room temperature and a pressure of 10 MPa to obtain the composite material.

[0051] Example 2

[0052] S1: The LED chip wastewater is first coarsely filtered through a grid to remove large particles of impurities and sediment in the wastewater;

[0053] S2: Collect the wastewater after coarse filtration and pass it into regulating tank 1, into which a 10% mass fraction sodium hydroxide solution is added; then pass it into regulating tank 2, into which a 10% mass fraction sulfuric acid solution is added, collect the wastewater after conditioning, add the composite material to the wastewater, and stir for 0.5h;

[0054] S3: The wastewater treated in S2 is filtered through an ultrafiltration membrane, which is a ceramic membrane with a pore size of 10 nm, to obtain a clear liquid;

[0055] S4: The clear liquid obtained in S3 is concentrated by a reverse osmosis membrane to a concentration of 2.5 times;

[0056] S5: The concentrated supernatant from S4 is passed through a cation exchange resin;

[0057] S6: Pass ozone into the clear liquid obtained in S5 for sterilization. The ozone flow rate is 20 m / s and the sterilization time is 1 hour. The treated waste liquid is discharged.

[0058] The preparation method of the composite material in S2 is as follows:

[0059] S2.1: Dissolve chitosan in acetic acid solution with a volume fraction of 2% and stir at 150 r / min for 0.5 h to prepare a mixed solution A with a mass fraction of 30%;

[0060] S2.2: Grind the vermiculite in a ball mill at 400 rpm for 0.5 h to obtain vermiculite powder with a particle size of 150 mesh;

[0061] S2.3: Add vermiculite powder to mixed solution A, wherein the mass ratio of vermiculite to chitosan is 2:3, and add 0.5 wt% glutaraldehyde. Slowly heat the mixture from room temperature to 60°C and stir for 2 h at a heating rate of 2°C / min to obtain a solid-liquid mixture B. Filter the solid-liquid mixture B, wash the filter residue with deionized water, and dry it at 80°C for 12 h to obtain a mixture C.

[0062] S2.4: Mixture C, activated carbon, nano-alumina, and nano-ferric oxide in a mass ratio of 2:1:1:1 were mixed and ground in a ball mill at 400 rpm for 0.5 h to obtain mixture D. The particle size of mixture D was 150 mesh.

[0063] S2.5: Press the mixture D into a sheet at room temperature and a pressure of 10 MPa to obtain the composite material.

[0064] Example 3

[0065] S1: The LED chip wastewater is first coarsely filtered through a grid to remove large particles of impurities and sediment in the wastewater;

[0066] S2: Collect the wastewater after coarse filtration, pass it into regulating tank 1, add a 10% potassium hydroxide solution by mass into regulating tank 1; then pass it into regulating tank 2, add a 10% hydrochloric acid solution by mass into regulating tank 2, collect the wastewater after conditioning, add the composite material into the wastewater, and stir for 0.5h;

[0067] S3: The wastewater treated in S2 is filtered through an ultrafiltration membrane, which is a ceramic membrane with a pore size of 7 nm, to obtain a clear liquid;

[0068] S4: The clear liquid obtained in S3 is concentrated by a reverse osmosis membrane to a concentration of 6 times;

[0069] S5: The concentrated supernatant from S4 is passed through a cation exchange resin;

[0070] S6: Pass ozone into the clear liquid obtained in S5 for sterilization. The ozone flow rate is 20 m / s and the sterilization time is 1 hour. The treated waste liquid is discharged.

[0071] The preparation method of the composite material in S2 is as follows:

[0072] S2.1: Dissolve chitosan in acetic acid solution with a volume fraction of 2% and stir at 150 r / min for 0.5 h to prepare a mixed solution A with a mass fraction of 50%;

[0073] S2.2: Grind the vermiculite in a ball mill at 400 rpm for 0.5 h to obtain vermiculite powder with a particle size of 150 mesh;

[0074] S2.3: Add vermiculite powder to mixed solution A, wherein the mass ratio of vermiculite to chitosan is 2:3, and add 2 wt% glutaraldehyde. Slowly heat the mixture from room temperature to 60°C and stir for 2 h at a heating rate of 2°C / min to obtain a solid-liquid mixture B. Filter the solid-liquid mixture B, wash the filter residue with deionized water, and dry it at 80°C for 12 h to obtain a mixture C.

[0075] S2.4: Mixture C, activated carbon, nano-alumina, and nano-ferric oxide in a mass ratio of 2:1:1:1 were mixed and ground in a ball mill at 400 rpm for 0.5 h to obtain mixture D. The particle size of mixture D was 150 mesh.

[0076] S2.5: Press the mixture D into a sheet at room temperature and a pressure of 10 MPa to obtain the composite material.

[0077] Comparative Example 1

[0078] In this comparative example, no vermiculite was added during the preparation of the composite material, and the remaining steps were the same as those in Example 1.

[0079] Comparative Example 2

[0080] In this comparative example, chitosan was not added during the preparation of the composite material, and the remaining steps were the same as those in Example 1.

[0081] Comparative Example 3

[0082] In this comparative example, no activated carbon was added during the preparation of the composite material, and the remaining steps were the same as those in Example 1.

[0083] Comparative Example 4

[0084] In this comparative example, nano-alumina was not added during the preparation of the composite material, and the remaining steps were the same as those in Example 1.

[0085] Comparative Example 5

[0086] In this comparative example, nano-iron oxide was not added during the preparation of the composite material, and the remaining steps were the same as those in Example 1.

[0087] The discharged waste liquid of the embodiment and comparative example was tested according to GB 39731-2020 standard, and the experimental results are summarized in the following table:

[0088]

[0089] Experiments have shown that the addition of composite materials has significantly improved the effect of wastewater treatment.

[0090] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for treating LED chip wastewater using a composite material, characterized in that: The specific process of the process is as follows: S1: The LED chip wastewater is first coarsely filtered through a grid to remove large particles of impurities and sediment in the wastewater; S2: Collect the wastewater after coarse filtration, pass it into regulating tank 1, add 10% alkali solution by mass into regulating tank 1; then pass it into regulating tank 2, add 10% acid solution by mass into regulating tank 2, collect the wastewater after conditioning, add a composite material combining chitosan, vermiculite, activated carbon, nano-alumina and nano-iron oxide into the wastewater, and stir for 0.5h; S3: filtering the wastewater treated in S2 through an ultrafiltration membrane to obtain a clear liquid; S4: The clear liquid obtained in S3 is concentrated by a reverse osmosis membrane to a concentration of 2.5-6 times; S5: The concentrated supernatant from S4 is passed through an ion exchange resin; S6: Pass ozone into the clear liquid obtained in S5 for sterilization, and discharge the treated waste liquid; Among them, the preparation method of the composite material in S2 includes: first preparing a chitosan vermiculite composite, adding glutaraldehyde as a cross-linking agent during the preparation of the chitosan vermiculite composite to form a stronger chemical bond between chitosan and vermiculite; then adding activated carbon, nano-alumina and nano-iron oxide to the chitosan vermiculite composite, the activated carbon serving as an adsorbent, the nano-alumina and nano-iron oxide serving as catalysts, the nano-alumina catalyzing the oxidation reaction of organic matter in the wastewater, and the nano-iron oxide accelerating the oxidation reaction; during the catalytic oxidation process, the microorganisms adsorbed on the surface of the activated carbon utilize the oxidants catalyzed by the nano-alumina and nano-iron oxide to further degrade the organic matter, thereby combining biodegradation with catalytic oxidation; the microorganisms adsorbed on the surface of the activated carbon also combine with the activated carbon and the chitosan vermiculite composite to remove organic matter in the wastewater by a combination of catalytic oxidation and adsorption, the nano-alumina and nano-iron oxide remove heavy metal ions by generating insoluble precipitates, the chitosan vermiculite composite and the activated carbon participate in this process, and further remove heavy metal pollution in the wastewater by adsorption; the specific preparation method is as follows, S2.1: Dissolve chitosan in acetic acid solution and stir at 150 r / min for 0.5 h to prepare a mixed solution A with a mass fraction of 30-50%. S2.2: Grind the vermiculite in a ball mill at 400 rpm for 0.5 h to obtain vermiculite powder with a particle size of 150 mesh; S2.3: Add vermiculite powder to mixed solution A, wherein the mass ratio of vermiculite to chitosan is 2:3, and then add 0.5-2 wt% glutaraldehyde. Slowly heat the mixture from room temperature to 60°C at a heating rate of 2°C / min and stir for 2 h to obtain a solid-liquid mixture B. Filter the solid-liquid mixture B, wash the filter residue with deionized water, and dry it at 80°C for 12 h to obtain a mixture C. S2.4: Mixture C, activated carbon, nano-alumina, and nano-ferric oxide in a mass ratio of 2:1:1:1 were mixed and ground in a ball mill at 400 rpm for 0.5 h to obtain mixture D. The particle size of mixture D was 150 mesh. S2.5: Press the mixture D into a sheet at room temperature and a pressure of 10 MPa to obtain the composite material.

2. The process for treating LED chip wastewater using a composite material according to claim 1, characterized in that: The alkali solution in S2 is one or more of ammonia water, sodium hydroxide solution, and potassium hydroxide solution.

3. The process for treating LED chip wastewater using a composite material according to claim 1, characterized in that: The acid solution in S2 is one or more of hydrochloric acid solution and sulfuric acid solution.

4. The process for treating LED chip wastewater using a composite material according to claim 1, characterized in that: The ultrafiltration membrane in S3 is a ceramic membrane with a pore size of 4-10 nm.

5. The process for treating LED chip wastewater using a composite material according to claim 1, characterized in that: The ion exchange resin in S5 is a cation exchange resin.

6. The process for treating LED chip wastewater using a composite material according to claim 1, characterized in that: The ozone flow rate in S6 is 20 m / s, and the sterilization time is 1 h.

7. The process for treating LED chip wastewater using a composite material according to claim 1, characterized in that: The volume fraction of the acetic acid solution in S2.1 is 2%.

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