A high-efficiency domestic garbage leachate treating agent and preparation method thereof

Abstract

The present invention discloses a high-efficiency domestic garbage leachate treatment agent and a preparation method thereof, and belongs to the technical field of sewage treatment. The treatment agent is composed of agent A and agent B; agent A is a composite microbial agent, agent B is a composite chemical treatment agent, and the composite chemical treatment agent is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles in a mass ratio of 3:1. The domestic garbage leachate treatment agent of the present invention adopts a combination of biological-physical-chemical methods, has an excellent treatment effect on garbage leachate with complex components, can effectively remove heavy metals, ammonia nitrogen, total nitrogen, total phosphorus, organic waste and other harmful substances in wastewater, has good chromaticity, makes the treated garbage leachate meet the discharge standard, and has good market application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to a high-efficiency domestic garbage leachate treating agent and a preparation method thereof. Background Art

[0002] At present, the amount of urban domestic garbage is increasing year by year. After being transported to landfills and further processed, the garbage will form a series of landfills. The liquid formed in the landfill will have a great impact on the air and surrounding geology. Moreover, this pollution is very different from ordinary urban wastewater pollution, which will bring great difficulties to governance. Leachate is a special wastewater with complex components generated in the process of garbage landfill, including organic matter, NH 4 + -N, TN and other contents are high. If they are not treated, once they seep into the ground, they will not only pollute the groundwater source, but also pollute the surrounding areas with the flow of groundwater, destroying the ecological environment and posing a threat to the health of humans and animals. Due to the wide range of garbage sources, the composition of garbage leachate is very complex. It contains both organic and inorganic substances, as well as a large amount of heavy metals. Domestic garbage leachate is secondary pollution generated after the sanitary landfill of urban domestic garbage. It has the characteristics of a wide variety of pollutants, a large amount of water, large fluctuations in water quality and no periodic changes. These characteristics make the treatment of garbage leachate extremely difficult and costly.

[0003] At present, the treatment methods for landfill leachate include physical treatment, chemical treatment and biological treatment. The physical method mainly uses physical or mechanical methods to treat the leachate, including screening, centrifugation, sedimentation and flotation, etc., which is generally used as the most basic treatment method; the chemical method generally causes chemical reagents to neutralize, flocculate, and redox react with pollutants to remove pollutants. However, when existing chemical reagents such as polyaluminium chloride are used to treat sewage, the amount is large, the flocculants are loose and large in size, and it is not easy to filter; the biological treatment method relies on the metabolism of microorganisms to remove organic matter in the leachate, which is mainly suitable for fresh leachate with good biodegradability, and has the advantages of good treatment effect and low cost. The physicochemical treatment is simpler and more efficient, and is suitable for leachate that is difficult to be biodegraded, and is often used in pretreatment and deep treatment processes. Although physical, chemical and biological treatment methods have their own advantages, the treatment effect of using a single treatment method for leachate with complex components is not ideal for domestic waste leachate. However, the MBR+NF+RO process in the existing domestic waste leachate treatment technology has the characteristics of high equipment cost and complex operation. Therefore, how to provide a low-cost, efficient and easy-to-operate domestic waste leachate treatment agent to optimize the leachate treatment process has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a high-efficiency domestic garbage leachate treating agent, which adopts a biological-physical-chemical combination method, selects a composite microbial agent composed of a combination of dominant strains as an agent A to perform preliminary treatment on the garbage leachate, and then uses an agent B composed of a compound of magnetic nanoparticles and ZnO nanoparticles with photocatalytic activity to treat the garbage leachate, thereby achieving an excellent treatment effect on the garbage leachate. The treated garbage leachate has good chromaticity, COD, and nitrogen and phosphorus removal rate, and significantly improves water quality to meet the discharge standard.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0006] A high-efficiency domestic garbage leachate treating agent is composed of agent A and agent B; agent A is a composite microbial agent, agent B is a composite chemical treating agent, and the composite chemical treating agent is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles in a mass ratio of 3:1.

[0007] Preferably, the composite microbial agent is prepared by the following method: Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus aggregatis are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 28-30°C and 180 r / min until OD 600 ≈1.0, inoculate 2% of the seed liquid into 200 mL of fermentation liquid medium, ferment and culture at 28-30°C and 180 r / min for 12 h, stop the fermentation to obtain three fermentation broths, and then mix them in a volume ratio of 1:1:1 to obtain a composite microbial agent.

[0008] More preferably, the LB liquid culture medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 1000 mL distilled water, the pH is adjusted to 7.0; and steam sterilized at 121°C for 20 min.

[0009] More preferably, the LB solid culture medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 15 g agar powder, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min.

[0010] Preferably, the Phanerochaete chrysosporium is deposited with CGMCC No.3.7212, purchased from China General Microorganism Culture Collection Administration Center, and deposited on June 27, 2005; the Acinetobacter junii is deposited with CGMCC No.1.8037, purchased from China General Microorganism Culture Collection Administration Center, and deposited on May 8, 2008; the Bacillus arguingii is deposited with CGMCC No.1.15821, purchased from China General Microorganism Culture Collection Administration Center, and deposited on September 10, 2016. Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus arguingii used in the present invention can be purchased through the strain catalog of the collection center without the need for additional preservation.

[0011] Preferably, the fermentation liquid medium is composed of: 10 g glucose, 5 g beef extract, 1.5 g sodium chloride, FeSO 4 7H 2 O 0.05 g, K 2 HPO 4 0.15 g, ZnSO 4 7H 2 O 0.5g, distilled water 1000ml, pH 7.0, sterilization conditions: 121℃, 30 min.

[0012] Preferably, the magnetic nanoparticles are prepared by the following method: 2.377 g NiCl 2 6H 2 O and 3.244 g FeCl 3 Add to 100 ml of deionized water and stir evenly, then add 12.3 g of sodium acetate, 3 g of trisodium citrate and 1 g of PEG4000, stir and continue ultrasonic treatment for 30 minutes, then transfer the mixed solution to a polytetrafluoroethylene hydrothermal reactor, react at 200 ° C for 12-16 hours, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, and vacuum dry it at 75 ° C for 6 hours to obtain magnetic nanoparticles.

[0013] Preferably, in the high-efficiency domestic waste leachate treating agent, the Mn-doped ZnO nanoparticles are prepared by the following method:

[0014] (1) Accurately weigh 27.522 g of zinc acetate and 2.08 g of manganese acetate, respectively, and then add them to 200 ml of deionized water and stir until they are completely dissolved. Then, add 7.2 g of citric acid and continue stirring for 10-15 minutes. Then, add 40 ml of anhydrous ethanol and stir evenly to form a mixed solution.

[0015] (2) Slowly add 3 mol / L KOH solution to the above mixed solution until the pH value of the mixed solution reaches 7.0. After magnetic stirring for 30 min, transfer it into a polytetrafluoroethylene hydrothermal reactor and react at 180°C for 12 h. Naturally cool it to room temperature. After filtering the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, vacuum dry it at 80°C for 6 h, and then place it in a muffle furnace for calcination at 500°C for 2 h. After cooling to room temperature, grind it to obtain the product.

[0016] Preferably, when in use, the mass ratio of agent A to agent B is 2:1; when treating 1L of domestic waste leachate, the amount of agent A is 20g and the amount of agent B is 10g.

[0017] Preferably, when in use, after adding agent A, stir and culture at 200 r / min at 28-30°C for 24 hours, then add agent B, stir evenly, irradiate with a 300W xenon lamp for 3 hours, and then separate the solid and liquid.

[0018] The present invention also provides a method for preparing the above-mentioned high-efficiency domestic garbage leachate treating agent, which comprises the following steps:

[0019] S1: preparing a composite microbial agent to obtain agent A;

[0020] S2: preparing magnetic nanoparticles and Mn-doped ZnO nanoparticles respectively, and mixing the two in a mass ratio of 3:1 to obtain agent B;

[0021] S3: Package Agent A and Agent B separately, mix and pack them into bags to obtain the final product.

[0022] The high-efficiency domestic garbage leachate treating agent of the present invention has a good treating effect on the garbage leachate with a pH value in the range of 3.0-10.0, and the water quality after the treatment can meet the discharge standard of the "Pollution Control Standard for Domestic Garbage Landfill" (GB16889-2008).

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) The composite microbial agent composed of the selected superior strains was used to treat the leachate of domestic garbage. The components complemented each other and jointly improved the pollutant removal capacity in the leachate of garbage. Among them, Phanerochaete chrysosporium can secrete a variety of extracellular enzymes, which can work synergistically to effectively degrade lignin structure, cellulose, hemicellulose, pectin and other high molecular polymers, and can also degrade polycyclic aromatic hydrocarbons, dyes and other organic and toxic substances; Acinetobacter junii can use organic acids, amino acids and other organic matter in sewage as food, and decompose them into carbon dioxide, water and other inorganic substances through aerobic respiration or anaerobic respiration, which not only removes organic matter in sewage, but also reduces the amount of BOD and COD in sewage, thereby improving the cleanliness of water quality; Bacillus agglomerans can adapt to some special environments (such as high salt, high temperature, etc.), and can also degrade organic matter in organic wastewater, promote denitrification and dephosphorization of wastewater, and further purify water quality. The three strains work synergistically to better degrade pollutants in the leachate of domestic garbage.

[0025] 2) The agent B of the present invention is a compound of magnetic nanoparticles with adsorption effect and ZnO nanoparticles with photocatalytic activity. The magnetic nanoparticles of the present invention are Ni-doped magnetic nanoparticles. The number of atoms on the surface of the nanoparticles increases, the coordination number of the surface atoms is insufficient and the surface energy is high, so that these surface atoms have high activity and are extremely unstable, and are easy to combine with other atoms. Therefore, the surface of the nickel-doped ferromagnetic nanoparticles has more active sites and can more effectively adsorb organic pollutants and heavy metal ions; while the Mn-doped ZnO nanoparticles significantly reduce the particle size of the ZnO nanoparticles. 2+ The doping of ZnO will cause the oxygen vacancies on the surface of ZnO to adsorb more oxygen. More oxygen means that more ·O can be generated through reduction reaction. 2- , and then produce hydroxide and hydrogen peroxide, thus achieving a better photocatalytic degradation of organic pollutants. When the two are used in combination, they play a synergistic role. The adsorbent can adsorb organic matter and other pollutants in the sewage and enrich them around the photocatalyst, thereby increasing the concentration of pollutants around the photocatalyst. This enrichment effect makes the photocatalytic reaction more efficient, because the photocatalyst can catalytically decompose these adsorbed pollutants under light and convert them into harmless substances.

[0026] 3) The present invention treats the leachate of domestic waste by combining microorganism-physical adsorption-chemical catalytic degradation, which has a good treatment effect, the treatment agent is simple and easy to operate, the treatment cost is low, and the COD, BOD, and NH 4 + -N, TP, TN, chromaticity and other indicators all meet the emission standards of "Pollution Control Standards for Municipal Waste Landfills" (GB16889-2008). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The surface morphology of the ZnO nanoparticles prepared in the present invention before and after being doped with Mn is shown in electron microscope images, wherein a is pure ZnO nanoparticles, and b is Mn-doped ZnO nanoparticles;

[0028] Figure 2 A comparison diagram of landfill leachate before and after treatment with the high-efficiency domestic landfill leachate treating agent of the present invention;

[0029] Figure 3 This is a graph showing the effect of different formulation ratios of agent B in the high-efficiency domestic waste leachate treatment agent of the present invention on the COD removal rate in the landfill leachate. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto. Raw materials and reagents used in the present invention are commercially available unless otherwise specified. The deposit number of the Phanerochaete chrysosporium used in the present invention is CGMCC No.3.7212, purchased from the China General Microbiological Culture Collection Administration Center, and the deposit date is June 27, 2005; the deposit number of the Acinetobacter junii is CGMCC No.1.8037, purchased from the China General Microbiological Culture Collection Administration Center, and the deposit date is May 8, 2008; the deposit number of the Bacillus arguta is CGMCC No.1.15821, purchased from the China General Microbiological Culture Collection Administration Center, and the deposit date is September 10, 2016. The Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus arguta used in the present invention can be purchased through the strain catalog of the collection center without the need for additional preservation.

[0031] Example 1

[0032] A high-efficiency domestic garbage leachate treating agent is composed of agent A and agent B; agent A is a composite microbial agent, agent B is a composite chemical treating agent, and the composite chemical treating agent is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles in a mass ratio of 3:1.

[0033] The preparation method of the above-mentioned high-efficiency domestic garbage leachate treating agent is as follows:

[0034] S1: Prepare a composite microbial agent to obtain agent A:

[0035] The preparation method of the composite microbial agent is as follows: Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus aggregatis are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 28°C and 180 r / min until OD 600≈1.0, inoculate 2% of the seed liquid into 200 mL of fermentation liquid medium, ferment and culture at 28°C and 180 r / min for 12 h, stop the fermentation to obtain three fermentation broths, and then mix them in a volume ratio of 1:1:1 to obtain a composite microbial agent;

[0036] The LB liquid culture medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min;

[0037] The LB solid medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 15 g agar powder, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min;

[0038] The fermentation liquid medium consists of: 10 g glucose, 5 g beef extract, 1.5 g sodium chloride, FeSO 4 7H 2 O0.05 g, K 2 HPO 4 0.15 g, ZnSO 4 7H 2 O 0.5g, distilled water 1000ml, pH 7.0, sterilization conditions: 121℃, 30min.

[0039] S2: Prepare magnetic nanoparticles and Mn-doped ZnO nanoparticles respectively:

[0040] The preparation method of the magnetic nanoparticles is as follows: 2.377 g NiCl 2 6H 2 O and 3.244 g FeCl 3 Add to 100 ml of deionized water and stir evenly, then add 12.3 g of sodium acetate, 3 g of trisodium citrate and 1 g of PEG4000, stir and continue ultrasonic treatment for 30 min, then transfer the mixed solution to a polytetrafluoroethylene hydrothermal reactor, react at 200 ° C for 12 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, and vacuum dry it at 75 ° C for 6 h to obtain magnetic nanoparticles;

[0041] The preparation method of the Mn-doped ZnO nanoparticles is as follows:

[0042] (1) Accurately weigh 27.522 g of zinc acetate and 2.08 g of manganese acetate, respectively, and then add them to 200 ml of deionized water and stir until they are completely dissolved. Then, add 7.2 g of citric acid and continue stirring for 10 min. Then, add 40 ml of anhydrous ethanol and stir evenly to form a mixed solution.

[0043] (2) Slowly add 3 mol / L KOH solution to the above mixed solution until the pH value of the mixed solution reaches 7.0, stir magnetically for 30 min, transfer to a polytetrafluoroethylene hydrothermal reactor, react at 180°C for 12 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, vacuum dry it at 80°C for 6 h, and then place it in a muffle furnace for calcination at 500°C for 2 h, cool it to room temperature, and grind it to obtain the product;

[0044] The magnetic nanoparticles prepared above and the Mn-doped ZnO nanoparticles were mixed in a mass ratio of 3:1 to obtain agent B.

[0045] S3: Package Agent A and Agent B separately, mix and pack them into bags to obtain the final product.

[0046] When the prepared high-efficiency domestic waste leachate treating agent of the present invention is used, the dosage ratio of agent A to agent B is 2:1; taking the treatment of 1L domestic waste leachate as an example, the dosage of agent A is 20g and the dosage of agent B is 10g. The specific method of use is: first add agent A, stir and cultivate at 200 r / min at 28°C for 24h, then add agent B, stir evenly, irradiate with a 300W xenon lamp for 3h, and then separate the solid and liquid.

[0047] Example 2

[0048] A high-efficiency domestic garbage leachate treating agent is composed of agent A and agent B; agent A is a composite microbial agent, agent B is a composite chemical treating agent, and the composite chemical treating agent is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles in a mass ratio of 3:1.

[0049] The preparation method of the above-mentioned high-efficiency domestic garbage leachate treating agent is as follows:

[0050] S1: Prepare a composite microbial agent to obtain agent A:

[0051] The preparation method of the composite microbial agent is as follows: Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus aggregatis are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 30°C and 180 r / min until OD 600 ≈1.0, inoculate 2% of the seed liquid into 200 mL of fermentation liquid medium, ferment and culture at 30°C and 180 r / min for 12 h, stop the fermentation to obtain three fermentation broths, and then mix them in a volume ratio of 1:1:1 to obtain a composite microbial agent;

[0052] The LB liquid culture medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min;

[0053] The LB solid medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 15 g agar powder, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min;

[0054] The fermentation liquid medium consists of: 10 g glucose, 5 g beef extract, 1.5 g sodium chloride, FeSO 4 7H 2 O0.05 g, K 2 HPO 4 0.15 g, ZnSO 4 7H 2 O 0.5g, distilled water 1000ml, pH 7.0, sterilization conditions: 121℃, 30min.

[0055] S2: Prepare magnetic nanoparticles and Mn-doped ZnO nanoparticles respectively:

[0056] The preparation method of the magnetic nanoparticles is as follows: 2.377 g NiCl 2 6H 2 O and 3.244 g FeCl 3 Add to 100 ml of deionized water and stir evenly, then add 12.3 g of sodium acetate, 3 g of trisodium citrate and 1 g of PEG4000, stir and continue ultrasonic treatment for 30 min, then transfer the mixed solution to a polytetrafluoroethylene hydrothermal reactor, react at 200 ° C for 14 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, and vacuum dry it at 75 ° C for 6 h to obtain magnetic nanoparticles;

[0057] The preparation method of the Mn-doped ZnO nanoparticles is as follows:

[0058] (1) Accurately weigh 27.522 g of zinc acetate and 2.08 g of manganese acetate, respectively, and then add them to 200 ml of deionized water and stir until they are completely dissolved. Then, add 7.2 g of citric acid and continue stirring for 15 min. Then, add 40 ml of anhydrous ethanol and stir evenly to form a mixed solution.

[0059] (2) Slowly add 3 mol / L KOH solution to the above mixed solution until the pH value of the mixed solution reaches 7.0, stir magnetically for 30 min, transfer to a polytetrafluoroethylene hydrothermal reactor, react at 180°C for 12 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, vacuum dry it at 80°C for 6 h, and then place it in a muffle furnace for calcination at 500°C for 2 h, cool it to room temperature, and grind it to obtain the product;

[0060] The magnetic nanoparticles prepared above and the Mn-doped ZnO nanoparticles were mixed in a mass ratio of 3:1 to obtain agent B.

[0061] S3: Package Agent A and Agent B separately, mix and pack them into bags to obtain the final product.

[0062] When the prepared high-efficiency domestic waste leachate treating agent of the present invention is used, the dosage ratio of agent A to agent B is 2:1; taking the treatment of 1L domestic waste leachate as an example, the dosage of agent A is 20g and the dosage of agent B is 10g. The specific method of use is: first add agent A, stir and cultivate at 30°C and 200 r / min for 24h, then add agent B, stir evenly, irradiate with a 300W xenon lamp for 3h, and then separate the solid and liquid.

[0063] Example 3

[0064] A high-efficiency domestic garbage leachate treating agent is composed of agent A and agent B; agent A is a composite microbial agent, agent B is a composite chemical treating agent, and the composite chemical treating agent is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles in a mass ratio of 3:1.

[0065] The preparation method of the above-mentioned high-efficiency domestic garbage leachate treating agent is as follows:

[0066] S1: Prepare a composite microbial agent to obtain agent A:

[0067] The preparation method of the composite microbial agent is as follows: Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus aggregatis are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 29°C and 180 r / min until OD 600 ≈1.0, inoculate 2% of the seed liquid into 200 mL of fermentation liquid medium, ferment and culture at 29°C and 180 r / min for 12 h, stop the fermentation to obtain three fermentation broths, and then mix them in a volume ratio of 1:1:1 to obtain a composite microbial agent;

[0068] The LB liquid culture medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min;

[0069] The LB solid medium is composed of: 5 g yeast extract, 10 g tryptone, 10 g sodium chloride, 15 g agar powder, 1000 mL distilled water, pH adjusted to 7.0; and steam sterilized at 121°C for 20 min;

[0070] The fermentation liquid medium consists of: 10 g glucose, 5 g beef extract, 1.5 g sodium chloride, FeSO 4 7H 2 O0.05 g, K 2 HPO 4 0.15 g, ZnSO 4 7H 2 O 0.5g, distilled water 1000ml, pH 7.0, sterilization conditions: 121℃, 30min.

[0071] S2: Prepare magnetic nanoparticles and Mn-doped ZnO nanoparticles respectively:

[0072] The preparation method of the magnetic nanoparticles is as follows: 2.377 g NiCl 2 6H 2 O and 3.244 g FeCl 3 Add to 100 ml of deionized water and stir evenly, then add 12.3 g of sodium acetate, 3 g of trisodium citrate and 1 g of PEG4000, stir and continue ultrasonic treatment for 30 min, then transfer the mixed solution to a polytetrafluoroethylene hydrothermal reactor, react at 200 ° C for 16 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, and vacuum dry it at 75 ° C for 6 h to obtain magnetic nanoparticles;

[0073] The preparation method of the Mn-doped ZnO nanoparticles is as follows:

[0074] (1) Accurately weigh 27.522 g of zinc acetate and 2.08 g of manganese acetate, respectively, and then add them to 200 ml of deionized water and stir until they are completely dissolved. Then, add 7.2 g of citric acid and continue stirring for 15 min. Then, add 40 ml of anhydrous ethanol and stir evenly to form a mixed solution.

[0075] (2) Slowly add 3 mol / L KOH solution to the above mixed solution until the pH value of the mixed solution reaches 7.0, stir magnetically for 30 min, transfer to a polytetrafluoroethylene hydrothermal reactor, react at 180°C for 12 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, vacuum dry it at 80°C for 6 h, and then place it in a muffle furnace for calcination at 500°C for 2 h, cool it to room temperature, and grind it to obtain the product;

[0076] The magnetic nanoparticles prepared above and the Mn-doped ZnO nanoparticles were mixed in a mass ratio of 3:1 to obtain agent B.

[0077] S3: Package Agent A and Agent B separately, mix and pack them into bags to obtain the final product.

[0078] When the prepared high-efficiency domestic waste leachate treating agent of the present invention is used, the dosage ratio of agent A to agent B is 2:1; taking the treatment of 1L domestic waste leachate as an example, the dosage of agent A is 20g and the dosage of agent B is 10g. The specific method of use is: first add agent A, stir and cultivate at 29°C and 200 r / min for 24h, then add agent B, stir evenly, irradiate with a 300W xenon lamp for 3h, and then separate the solid and liquid.

[0079] Comparative Example 1

[0080] A high-efficiency domestic waste leachate treatment agent, the raw material composition and preparation method of which are basically the same as those of Example 3, the only difference being that the composite microbial agent of agent A is made of Phanerochaete chrysosporium and Acinetobacter junii; the specific preparation method of the composite microbial agent is as follows: Phanerochaete chrysosporium and Acinetobacter junii are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 29°C and 180 r / min until OD 600 ≈1.0, the seed liquid was inoculated into 200 mL of fermentation liquid medium at 2% and fermented at 29°C and 180 r / min for 12 h. The fermentation was stopped to obtain three kinds of fermentation broths, which were then mixed in a volume ratio of 1:1 to obtain a composite microbial agent.

[0081] Comparative Example 2

[0082] A high-efficiency domestic waste leachate treatment agent, the raw material composition and preparation method of which are basically the same as those of Example 3, the only difference being that the composite microbial agent of agent A is made of Phanerochaete chrysosporium and Bacillus agnesii; the specific preparation method of the composite microbial agent is as follows: Phanerochaete chrysosporium and Bacillus agnesii are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 29°C and 180 r / min until OD 600≈1.0, the seed liquid was inoculated into 200 mL of fermentation liquid medium at 2% and fermented at 29°C and 180 r / min for 12 h. The fermentation was stopped to obtain three kinds of fermentation broths, which were then mixed in a volume ratio of 1:1 to obtain a composite microbial agent.

[0083] Comparative Example 3

[0084] A high-efficiency domestic waste leachate treatment agent, the raw material composition and preparation method of which are basically the same as those of Example 3, the only difference being that the composite microbial agent of agent A is made of Acinetobacter junii and Bacillus aggrad; the specific preparation method of the composite microbial agent is as follows: Acinetobacter junii and Bacillus aggrad are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 29°C and 180 r / min until OD 600 ≈1.0, the seed liquid was inoculated into 200 mL of fermentation liquid medium at 2% and fermented at 29°C and 180 r / min for 12 h. The fermentation was stopped to obtain three kinds of fermentation broths, which were then mixed in a volume ratio of 1:1 to obtain a composite microbial agent.

[0085] Comparative Example 4

[0086] A highly efficient domestic waste leachate treating agent, whose raw material composition and preparation method are basically the same as those in Example 3, the only difference being that agent B is only magnetic nanoparticles.

[0087] Comparative Example 5

[0088] A highly efficient domestic waste leachate treating agent, whose raw material composition and preparation method are basically the same as those in Example 3, the only difference being that agent B is only Mn-doped ZnO nanoparticles.

[0089] Comparative Example 6

[0090] A highly efficient domestic waste leachate treatment agent, the raw material composition and preparation method of which are basically the same as those in Example 3, except that agent B is composed of magnetic nanoparticles and pure ZnO nanoparticles in a mass ratio of 3:1. The preparation method of zinc oxide nanoparticles is as follows:

[0091] (1) Accurately weigh 27.522 g of zinc acetate, add it to 200 ml of deionized water and stir until it is completely dissolved, then add 7.2 g of citric acid and continue stirring for 15 min, then add 40 ml of anhydrous ethanol and stir evenly to form a mixed solution;

[0092] (2) Slowly add 3 mol / L KOH solution to the above mixed solution until the pH value of the mixed solution reaches 7.0. After magnetic stirring for 30 min, transfer it into a polytetrafluoroethylene hydrothermal reactor and react at 180°C for 12 h. Naturally cool it to room temperature. After filtering the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, vacuum dry it at 80°C for 6 h, and then place it in a muffle furnace for calcination at 500°C for 2 h. After cooling to room temperature, grind it to obtain the product.

[0093] Performance Testing

[0094] The domestic waste leachate from the landfill treatment plant in Bancheng Town, Lanshan District, Linyi City was selected, and the water quality before treatment was measured. Then, the domestic waste leachate treatment agents prepared in Examples 1-3 and Comparative Examples 1-6 were used to treat the leachate, and the water quality after treatment was measured. The test results are shown in Table 1.

[0095] Table 1 Water quality test results

[0096]

[0097] It can be seen from the data in Table 1 above that by comparing the data of Examples 1-3 of the present invention with those of Comparative Examples 1-3, after changing the composition of the composite microbial agent, the contents of COD, BOD, ammonia nitrogen, total nitrogen, total phosphorus, heavy metal lead and mercury in the treated water are significantly higher, and do not meet the corresponding emission standards. This is because the three strains in the composite microbial agent of the present invention have a synergistic effect. When used in combination, they can achieve better degradation of organic pollutants in wastewater, promote denitrification and dephosphorization of wastewater, and further purify water quality. The lack of one will weaken the effect. It can be seen from the data of Comparative Examples 4-5 that the composite chemical treatment agent used in the present invention is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles, which have obvious synergistic effects. Taking the COD removal effect as an example, the COD removal rate of Comparative Example 4 is 47.4%, the COD removal rate in Comparative Example 5 is 46.4%, and the average COD removal rate in Examples 1-3 is 99.3%. The results of Comparative Example 6 show that after Mn doped ZnO nanoparticles, the particle size of ZnO nanoparticles is significantly reduced, and Mn 2+ The doping of will improve the catalytic activity of ZnO nanoparticles, and the synergistic effect is better when used in combination with the magnetic nanoparticles of the present invention, thereby achieving a better effect of degrading organic pollutants.

[0098] In order to further illustrate the effect of the high-efficiency domestic waste leachate treatment agent prepared by the present invention, the present invention also studies the influence of agent B composed of different proportions on the treated water quality. Taking the COD content in the inlet and outlet water quality as an example, this test example selects the landfill leachate of a domestic waste treatment station as the test sample, and the COD content in the initial leachate is 3589 mg / L. The test sets up 5 treatment groups, and the high-efficiency domestic waste leachate treatment agent prepared by the present invention is used for treatment. The specific dosage is: when treating 1L of domestic waste leachate, the dosage of agent A is 20g, and the dosage of agent B is 10g; the method of use is: after adding agent A, stir and cultivate at 200 r / min at 28-30℃ for 24h, then add agent B, stir evenly, use 300W xenon lamp to irradiate for 3h, and then separate the solid and liquid. The mass ratios of magnetic nanoparticles and Mn-doped ZnO nanoparticles in agent B in groups 1-5 were 1:1, 2:1, 3:1, 4:1, and 5:1, respectively. After treatment, the COD content of the effluent was tested and the COD removal rate was statistically analyzed. The specific results are as follows: Figure 3 As shown. Figure 3 The results show that the formula composition ratio of agent B in the present invention is the best combination.

[0099] It should be noted that the above embodiments are only partial embodiments of the preferred methods of implementing the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

Claims

1. A highly efficient domestic waste leachate treating agent, characterized in that: The invention is composed of agent A and agent B; the agent A is a composite microbial agent, and the agent B is a composite chemical treatment agent, wherein the composite chemical treatment agent is composed of magnetic nanoparticles and Mn-doped ZnO nanoparticles in a mass ratio of 3:1; The composite microbial agent is prepared by the following method: Phanerochaete chrysosporium, Acinetobacter junii, and Bacillus aggregatis are activated in LB solid culture medium respectively, and then a single colony is picked and inoculated into a test tube of LB liquid culture medium, and cultured at 28-30°C and 180 r / min until OD 600 ≈1.0, inoculate 2% of the seed liquid into 200 mL of fermentation liquid medium, ferment and culture at 28-30°C and 180 r / min for 12 h, stop fermentation to obtain three fermentation broths, and then mix them in a volume ratio of 1:1:1 to obtain a composite microbial agent; The magnetic nanoparticles are prepared by the following method: 2.377g NiCl2·6H2O and 3.244g FeCl3 are added to 100ml deionized water and stirred evenly, and then 12.3g sodium acetate, 3g trisodium citrate and 1g PEG4000 are added, and after stirring, ultrasonic treatment is continued for 30min, and then the mixed solution is transferred to a polytetrafluoroethylene hydrothermal reactor, reacted at 200°C for 12-16h, and naturally cooled to room temperature. After filtering the reaction product, it is washed with anhydrous ethanol and deionized water for 3 times in sequence, and vacuum dried at 75°C for 6h to obtain magnetic nanoparticles; The Mn-doped ZnO nanoparticles are prepared by the following method: (1) Accurately weigh 27.522 g of zinc acetate and 2.08 g of manganese acetate, respectively, and then add them to 200 ml of deionized water and stir until they are completely dissolved. Then, add 7.2 g of citric acid and continue stirring for 10-15 minutes. Then, add 40 ml of anhydrous ethanol and stir evenly to form a mixed solution. (2) Slowly add 3 mol / L KOH solution to the above mixed solution until the pH value of the mixed solution reaches 7.0, stir magnetically for 30 min, transfer to a polytetrafluoroethylene hydrothermal reactor, react at 180°C for 12 h, cool naturally to room temperature, filter the reaction product, wash it with anhydrous ethanol and deionized water three times in sequence, vacuum dry it at 80°C for 6 h, and then place it in a muffle furnace for calcination at 500°C for 2 h, cool it to room temperature, and grind it to obtain the product; The deposit number of the Phanerochaete chrysosporium is CGMCC No.3.7212, which was purchased from the China General Microbiological Culture Collection Center, and the deposit date is June 27, 2005; the deposit number of the Acinetobacter junii is CGMCC No.1.8037, which was purchased from the China General Microbiological Culture Collection Center, and the deposit date is May 8, 2008; the deposit number of the Bacillus arnoldii is CGMCC No.1.15821, which was purchased from the China General Microbiological Culture Collection Center, and the deposit date is September 10, 2016.

2. The high-efficiency domestic waste leachate treating agent according to claim 1, characterized in that: The fermentation liquid culture medium is composed of: 10 g glucose, 5 g beef extract, 1.5 g sodium chloride, 0.05 g FeSO4·7H2O, 0.15 g K2HPO4, 0.5 g ZnSO4·7H2O, 1000 ml distilled water, pH 7.0, sterilization conditions: 121° C., 30 min.

3. The high-efficiency domestic waste leachate treating agent according to claim 1, characterized in that: When in use, the mass ratio of Agent A to Agent B is 2:1; when treating 1L of domestic waste leachate, the dosage of Agent A is 20g and the dosage of Agent B is 10g.

4. The high-efficiency domestic waste leachate treating agent according to claim 1, characterized in that: When in use, after adding agent A, stir and cultivate at 200 r / min at 28-30℃ for 24 hours, then add agent B. After stirring evenly, irradiate with a 300W xenon lamp for 3 hours, and then separate the solid and liquid.

5. A method for preparing a high-efficiency domestic waste leachate treating agent according to any one of claims 1 to 4, characterized in that: It includes the following steps: S1: preparing a composite microbial agent to obtain agent A; S2: preparing magnetic nanoparticles and Mn-doped ZnO nanoparticles respectively, and mixing the two in a mass ratio of 3:1 to obtain agent B; S3: Package Agent A and Agent B separately, mix and pack them into bags to obtain the final product.

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