A composite sewage treatment agent containing modified diatomite, and a preparation method and application thereof

Abstract

The application provides a composite sewage treatment agent containing modified diatomite and a preparation method and application thereof, and comprises the following components in mass fractions: 10-15 parts of composite plant fermentation liquor, 15-20 parts of polyaluminum chloride, 5-10 parts of sodium polyacrylate, 4-8 parts of ferric chloride, 15-25 parts of chitosan, 5-15 parts of bentonite, 40-50 parts of soybean straw ash, 65-75 parts of modified diatomite, 4-9 parts of sodium dodecyl sulfonate, 3-8 parts of potassium dihydrogen phosphate and 220-230 parts of water. The composite sewage treatment agent has good effects on treating papermaking wastewater, can remove organic pollutants and heavy metal pollution, has good treatment effects at low temperatures, and has high storage stability.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment agents, and particularly relates to a composite sewage treatment agent containing modified diatomaceous earth, a preparation method and an application thereof. Background Art

[0002] Papermaking wastewater refers to wastewater generated during the pulping and papermaking process. It includes pulping and cooking wastewater, washing wastewater, bleaching wastewater and paper machine white water. In the papermaking process, not only a lot of raw materials are used, but also the dependence on water resources is very high. In this case, paper mills will discharge a large amount of wastewater. If it is not treated in time, it will not only waste water resources, but also pollute the environment. Papermaking wastewater has complex components and poor biodegradability. It is a difficult-to-treat industrial wastewater and is one of the main sources of industrial pollution. Papermaking wastewater is one of the most obvious problems: high pollution. Compared with ordinary industrial wastewater, its concentration is higher, its internal chemical composition is very complex, and it is very difficult to degrade.

[0003] At present, there are some common problems in the practical application of papermaking wastewater treatment agents:

[0004] (1) Unstable effect:

[0005] Due to the complex composition and large concentration fluctuations of papermaking wastewater, traditional sewage treatment agents may find it difficult to maintain a stable treatment effect, especially when encountering shock loads, which may cause the treated water quality to substandard.

[0006] (2) Insufficient tolerance and selectivity:

[0007] Some sewage treatment agents are effective in removing specific types of pollutants, but have low removal efficiency for other types of pollutants (such as inks, resins, lignin, etc.), especially for the limited decolorization effect of difficult-to-degrade organic matter and colored substances.

[0008] (3) Short shelf life:

[0009] Some sewage treatment agents containing specific ingredients, such as polyaluminium chloride, have poor storage stability in hot and humid environments, which limits the use and transportation of the treatment agents.

[0010] (4) Insufficient ability to adapt to local conditions:

[0011] Although both are papermaking wastewater, the difficulty of treatment and specific problems are different due to differences in climate and geographical environment. Existing products rarely provide targeted pollution control based on the geographical conditions of specific areas, and the effects of general products are not ideal.

[0012] Therefore, there are still many problems to be solved in the sewage treatment agents in the prior art. Summary of the Invention

[0013] The present invention aims to provide a composite sewage treatment agent containing modified diatomaceous earth, a preparation method thereof, and an application thereof. The composite sewage treatment agent of the present invention has a good effect in treating papermaking wastewater, can remove organic pollutants and heavy metal pollution, has a good treatment effect even at low temperatures, and has high storage stability.

[0014] In order to achieve the above-mentioned object, the present invention provides a composite sewage treatment agent containing modified diatomaceous earth, comprising the following components in parts by weight: 10-15 parts of composite plant fermentation liquid, 15-20 parts of polyaluminum chloride, 5-10 parts of sodium polyacrylate, 4-8 parts of ferric chloride, 15-25 parts of chitosan, 5-15 parts of bentonite, 40-50 parts of soybean straw ash, 65-75 parts of modified diatomaceous earth, 4-9 parts of sodium dodecyl sulfonate, 3-8 parts of potassium dihydrogen phosphate and 220-230 parts of water.

[0015] The preparation method of the composite plant fermentation liquid is as follows:

[0016] S1: Mix acacia leaves, dried mint, dried orange peel, centipede grass, and dried reed with water in a mass ratio of 1:0.4-0.9:1.2-1.7:2.2-2.7:1.5-2:60, soak for 1-2 hours, heat at 70-75°C for 7-10 hours, and filter through a 0.25 μm filter membrane to obtain a filtrate;

[0017] S2: The filtrate, maltose, glucose and dry yeast were mixed in a mass ratio of 50:2:1:0.2-0.5, and the mixture was sealed and fermented at 30-35° C. for 4-6 days to obtain a composite plant fermentation liquid.

[0018] Dry yeast was from Hebei Kelongduo Biotechnology Co., Ltd.

[0019] Polyaluminum chloride was purchased from Henan Shuibiqing Environmental Protection Technology Co., Ltd.

[0020] Sodium polyacrylate, molecular weight 5-15 million, was purchased from Jiangsu Zhonghao Yuanda Environmental Engineering Co., Ltd.

[0021] Chitosan was purchased from Merck, product number 448869.

[0022] Bentonite was purchased from Merck, product number 682659.

[0023] Furthermore, the preparation method of the modified diatomaceous earth is:

[0024] (1) Mix polyaspartic acid: aminobenzenesulfonic acid and sodium hydroxide in a molar ratio of 1:0.4-0.8:0.2-0.6, add to water 15-20 times the mass of polyaspartic acid, and react at 500-1000 rpm for 1-2 hours under ice bath conditions to obtain a polyaspartic acid solution modified with sulfonic acid groups;

[0025] (2) adding diatomaceous earth, silane coupling agent KH550 and sodium dodecylbenzene sulfonate to the polyaspartic acid solution modified with sulfonic acid groups, wherein the mass of diatomaceous earth is 5-8 times the mass of polyaspartic acid, the mass of silane coupling agent KH550 is 0.05-0.08 times the mass of polyaspartic acid, and the mass of sodium dodecylbenzene sulfonate is 0.01-0.02 times the mass of polyaspartic acid, stirring at 40-50° C. for 3-4 hours, filtering, washing and drying to obtain modified diatomaceous earth.

[0026] Polyaspartic acid was purchased from Shandong Yuanlian Chemical Co., Ltd.

[0027] Furthermore, the diatomaceous earth is a compound of diatomaceous earth with an average particle size of 2.5-5.5 μm, diatomaceous earth with an average particle size of 8-13 μm and diatomaceous earth with an average particle size of 15-18 μm, with a mass ratio of (3-5): (2-3): 1.

[0028] The above diatomaceous earth all comes from Qingdao Shengtai Silicon Industry Co., Ltd.

[0029] In recent years, the Liaohekou Wetland in Liaoning Province has faced challenges with insufficient natural precipitation and poor water replenishment. Paper mills located within the wetland are mostly located along the river, discharging large amounts of wastewater. Consequently, paper mill wastewater has become an unavoidable source of water for irrigation. Due to its long geographical location, the Liaohekou Wetland experiences low water temperatures during certain periods of time. Existing wastewater treatment agents are less effective at these low temperatures. The present invention improves the treatment efficiency of wastewater treatment agents at low temperatures by using modified diatomaceous earth with a specific particle size distribution and a composite plant fermentation broth. It is speculated that the composite plant fermentation liquid prepared by the present invention adopts a combination of microorganisms and plant purification, and plays a role in purifying water bodies through the extracted effective purification components and microorganisms of plants; at the same time, the diatomaceous earth with a gradient particle size distribution is modified to increase the specific surface area, thereby improving the dispersion of components such as polyaluminum chloride and sodium polyacrylate at low temperatures, forming a load adsorption, and the treatment efficiency is high. At the same time, polyaspartic acid grafted sulfonate can enhance the chelating effect, and the sulfonic acid group can effectively attract and bind malodorous gas molecules such as ammonia and hydrogen sulfide. At the same time, the grafted sulfonic acid group will change the spatial configuration of the polyaspartic acid molecule, which is conducive to the distribution of more molecules on the diatomaceous earth surface, thereby increasing the load on the diatomaceous earth. At the same time, the addition of silane coupling agent KH550 and sodium dodecylbenzene sulfonate can promote the effective connection of the polyaspartic acid grafted sulfonic acid group to the diatomaceous earth surface, increase the load and load stability, and enhance the interfacial adhesion between inorganic and organic substances. Sodium dodecylbenzene sulfonate may be used to adjust the surface tension of the system, which helps to uniformly distribute polyaspartic acid on the diatomaceous earth surface and improve the reaction activity at low temperatures. Diatomaceous earth with finer particle sizes in the gradient particle size distribution has a larger specific surface area and a richer pore structure, which facilitates a more complete distribution of polyaspartic acid molecules on the surface of the diatomaceous earth particles and deep penetration into their internal pores, thereby increasing the loading capacity and improving adsorption performance. However, if the gradient particle size ratio is unbalanced, for example, if the diatomaceous earth particle size is too small, although the specific surface area is large, it may increase the operational difficulty during the loading process, such as increased viscosity and reduced fluidity. At the same time, overly fine particles may agglomerate during the loading process, which is not conducive to the sufficient loading of polyaspartic acid. The diatomaceous earth with a gradient particle size distribution selected in the present invention not only ensures sufficient specific surface area and pore structure to facilitate the loading of polyaspartic acid, but also achieves the stability and practicality of the composite material after loading, and enhances the adsorption capacity of the modified diatomaceous earth. Through the synergistic effects of multiple aspects, the present invention improves the efficiency of wastewater treatment at low temperatures.

[0030] Furthermore, the preparation method of soybean straw ash is:

[0031] (1) washing the soybean straw, drying it, and crushing it to a length of 1-5 mm to obtain soybean straw powder;

[0032] (2) carbonizing the soybean straw powder, specifically: carbonizing at a pressure of 0.005 Pa, a temperature of 700-800° C., and a time of 320-350 min to obtain carbonized soybean straw;

[0033] (3) adding water to the carbonized soybean straw to make its humidity reach 40-45%, adding composite bacteria and glucose and mixing them evenly, and aerobically fermenting them in a fermentation pit at 30-35° C. for 50-60 hours to obtain soybean straw ash.

[0034] Furthermore, in step (3), the composite bacteria are Bacillus subtilis, Lactobacillus plantarum and Klebsiella in a mass ratio of 1:1.3-1.6:0.4-0.7.

[0035] Bacillus subtilis, SHMCC (SHBCC) D10486, Shanghai Baocang Microorganism Co., Ltd.

[0036] Lactobacillus plantarum, strain number: SHMCC (SHBCC) D24745, Shanghai Baocang Microbiology Co., Ltd.

[0037] Klebsiella pneumoniae, strain number: SHBCC D19134, Shanghai Collection of Biotechnology Center.

[0038] Furthermore, in step (3), the mass of the composite bacteria accounts for 1-2% of the mass of the carbonized soybean straw, and the mass of the glucose is 100-150 times the mass of the composite bacteria.

[0039] In addition to organic matter, the main pollutants in papermaking wastewater also include a variety of heavy metal pollutants, including lead, copper, zinc, etc. Long-term sewage irrigation will cause the accumulation of heavy metals in plants. The present invention improves the removal effect of sewage treatment agents on heavy metals by adding fermented soybean straw ash to the sewage treatment agent, which works synergistically with the other components. The analysis shows that soybean straw ash can be carried inside modified diatomaceous earth and bentonite to form a mutually interpenetrating and carrying structure, thereby increasing the surface area and stability of sewage treatment agents for heavy metal adsorption. At the same time, the surface of the microbial cell wall adsorbed on the surface of the carbonized straw has functional groups with affinity, which can adsorb heavy metal ions and produce specific organic substances that can form precipitates with heavy metals, thereby precipitating heavy metal ions from water, realizing physical and biological synergistic treatment.

[0040] In addition, sewage treatment agents containing polyaluminium chloride usually need to be stored in a dry, moisture-proof, and cool environment, and their storage stability in hot and humid environments needs to be further improved. The inventors have found that the sewage treatment agent of the present invention also has high storage stability in hot and humid environments. Analysis shows that under these conditions, the components in these composite materials can reduce the hygroscopicity and anti-caking properties of polyaluminium chloride itself, maintain its dispersed state, and reduce the impact of humid environments on its performance. Some components in the composite materials have certain high-temperature antioxidant effects, which improves storage stability.

[0041] The second aspect of the present invention provides a method for preparing the composite sewage treatment agent containing modified diatomaceous earth, the preparation method comprising the following steps:

[0042] (1) mixing polyaluminium chloride, sodium polyacrylate, ferric chloride and water to obtain a first mixed solution;

[0043] (2) mixing chitosan, bentonite, soybean straw ash, and modified diatomaceous earth to obtain a second mixture;

[0044] (3) Add the first mixed liquid to the second mixture, stir and mix until uniform, then add the remaining components, mix and stir until uniform, and obtain a composite sewage treatment agent containing modified diatomaceous earth.

[0045] The third aspect of the present invention provides the use of the composite sewage treatment agent containing modified diatomaceous earth.

[0046] Furthermore, when used, a composite sewage treatment agent containing modified diatomaceous earth is added to sewage in an amount of 10-15 g / L, stirred and adsorbed for 15-20 minutes, and filtered.

[0047] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0048] 1. The composite sewage treatment agent of the present invention has a good effect in treating papermaking wastewater, can remove organic pollutants and heavy metal pollution, has a good treatment effect even at low temperatures, and has high storage stability.

[0049] 2. The present invention improves the sewage treatment effect of the sewage treatment machine at low temperature by adding modified diatomaceous earth to the sewage treatment agent.

[0050] 3. The present invention improves the removal effect of the sewage treatment agent on heavy metals by adding soybean straw ash to the sewage treatment agent to work synergistically with other components.

[0051] 4. When chitosan, bentonite, soybean straw ash and modified diatomaceous earth are compounded in a specific ratio, the sewage treatment agent of the present invention also has high storage stability in a hot and humid environment. DETAILED DESCRIPTION

[0052] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0053] Example 1

[0054] This embodiment provides a composite sewage treatment agent containing modified diatomaceous earth, comprising the following components in parts by mass: 12 parts of composite plant fermentation liquid, 17 parts of polyaluminum chloride, 8 parts of sodium polyacrylate, 6 parts of ferric chloride, 20 parts of chitosan, 10 parts of bentonite, 45 parts of soybean straw ash, 70 parts of modified diatomaceous earth, 6 parts of sodium dodecyl sulfate, 5 parts of potassium dihydrogen phosphate, and 225 parts of water.

[0055] The preparation method of the composite plant fermentation liquid is as follows:

[0056] S1: Mix Robinia pseudoacacia leaves, dried mint, dried orange peel, centipede grass, and dried reed with water in a mass ratio of 1:0.6:1.4:2.5:1.7:60, soak for 1.5 hours, heat at 73°C for 8 hours, and filter through a 0.25 μm filter membrane to obtain a filtrate;

[0057] S2: The filtrate, maltose, glucose and dry yeast were mixed in a mass ratio of 50:2:1:0.4, and the mixture was sealed and fermented at 30°C for 5 days to obtain a composite plant fermentation liquid.

[0058] Dry yeast was from Hebei Kelongduo Biotechnology Co., Ltd.

[0059] Polyaluminum chloride was purchased from Henan Shuibiqing Environmental Protection Technology Co., Ltd.

[0060] Sodium polyacrylate, molecular weight 5-15 million, was purchased from Jiangsu Zhonghao Yuanda Environmental Engineering Co., Ltd.

[0061] Chitosan was purchased from Merck, product number 448869.

[0062] Bentonite was purchased from Merck, product number 682659.

[0063] The preparation method of the modified diatomaceous earth is:

[0064] (1) Polyaspartic acid: aminobenzenesulfonic acid and sodium hydroxide in a molar ratio of 1:0.6:0.4 were mixed and added to water 20 times the mass of the polyaspartic acid. The mixture was reacted at 800 rpm for 1.6 h under ice bath conditions to obtain a polyaspartic acid solution modified with sulfonic acid groups.

[0065] (2) Adding diatomaceous earth, silane coupling agent KH550 and sodium dodecylbenzene sulfonate to the polyaspartic acid solution modified with sulfonic acid groups, wherein the mass of diatomaceous earth is 7 times the mass of polyaspartic acid, the mass of silane coupling agent KH550 is 0.07 times the mass of polyaspartic acid, and the mass of sodium dodecylbenzene sulfonate is 0.02 times the mass of polyaspartic acid, stirring at 45°C for 3.5 hours, filtering, washing and drying to obtain modified diatomaceous earth.

[0066] Polyaspartic acid was purchased from Shandong Yuanlian Chemical Co., Ltd.

[0067] The diatomaceous earth is a mixture of diatomaceous earth with an average particle size of 2.5-5.5 μm, diatomaceous earth with an average particle size of 8-13 μm, and diatomaceous earth with an average particle size of 15-18 μm, with a mass ratio of 3:2:1. The above diatomaceous earth is from Qingdao Shengtai Silicon Industry Co., Ltd.

[0068] The preparation method of soybean straw ash is:

[0069] (1) washing the soybean straw, drying it, and crushing it to a length of 1-5 mm to obtain soybean straw powder;

[0070] (2) carbonizing the soybean straw powder, specifically: carbonizing at a pressure of 0.005 Pa, a temperature of 750° C., and a time of 330 min to obtain carbonized soybean straw;

[0071] (3) Add water to the carbonized soybean straw to make its humidity reach 43%, add composite bacteria and glucose and mix evenly, and ferment aerobically at 30°C in a fermentation pit for 55 hours to obtain soybean straw ash.

[0072] The composite bacteria in step (3) are Bacillus subtilis, Lactobacillus plantarum and Klebsiella in a mass ratio of 1:1.4:0.5.

[0073] Bacillus subtilis, strain number: SHMCC (SHBCC) D10486, Shanghai Baocang Microbiology Co., Ltd.

[0074] Lactobacillus plantarum, strain number: SHMCC (SHBCC) D24745, Shanghai Baocang Microbiology Co., Ltd.

[0075] Klebsiella pneumoniae, strain number: SHBCC D19134, Shanghai Collection of Biotechnology Center.

[0076] The mass of the composite bacteria in step (3) accounts for 1.4% of the mass of the carbonized soybean straw, and the mass of the glucose is 120 times the mass of the composite bacteria.

[0077] The preparation method of the composite sewage treatment agent containing modified diatomaceous earth comprises the following steps:

[0078] (1) mixing polyaluminium chloride, sodium polyacrylate, ferric chloride and water to obtain a first mixed solution;

[0079] (2) mixing chitosan, bentonite, soybean straw ash, and modified diatomaceous earth to obtain a second mixture;

[0080] (3) Add the first mixed liquid to the second mixture, stir and mix until uniform, then add the remaining components, mix and stir until uniform, and obtain a composite sewage treatment agent containing modified diatomaceous earth.

[0081] Example 2

[0082] This embodiment provides a composite sewage treatment agent containing modified diatomaceous earth, comprising the following components in parts by mass: 15 parts of composite plant fermentation liquid, 15 parts of polyaluminum chloride, 10 parts of sodium polyacrylate, 4 parts of ferric chloride, 25 parts of chitosan, 5 parts of bentonite, 50 parts of soybean straw ash, 65 parts of modified diatomaceous earth, 9 parts of sodium dodecyl sulfate, 3 parts of potassium dihydrogen phosphate, and 220 parts of water.

[0083] The preparation method of the composite plant fermentation liquid is as follows:

[0084] S1: Mix Robinia pseudoacacia leaves, dried mint, dried orange peel, centipede grass, and dried reed with water in a mass ratio of 1:0.4:1.7:2.2:2:60, soak for 2 h, heat at 70°C for 10 h, and filter through a 0.25 μm filter membrane to obtain a filtrate;

[0085] S2: The filtrate, maltose, glucose and dry yeast were mixed in a mass ratio of 50:2:1:0.2, and the mixture was sealed and fermented at 30°C for 4 days to obtain a composite plant fermentation liquid.

[0086] Dry yeast was from Hebei Kelongduo Biotechnology Co., Ltd.

[0087] Polyaluminum chloride was purchased from Henan Shuibiqing Environmental Protection Technology Co., Ltd.

[0088] Sodium polyacrylate, molecular weight 5-15 million, was purchased from Jiangsu Zhonghao Yuanda Environmental Engineering Co., Ltd.

[0089] Chitosan was purchased from Merck, product number 448869.

[0090] Bentonite was purchased from Merck, product number 682659.

[0091] The preparation method of the modified diatomaceous earth is:

[0092] (1) Mix polyaspartic acid: aminobenzenesulfonic acid and sodium hydroxide in a molar ratio of 1:0.8:0.2, add the mixture into water 20 times the mass of the polyaspartic acid, and react at 1000 rpm for 2 h under ice bath conditions to obtain a polyaspartic acid solution modified with sulfonic acid groups;

[0093] (2) Adding diatomaceous earth, silane coupling agent KH550 and sodium dodecylbenzene sulfonate to the polyaspartic acid solution modified with sulfonic acid groups, wherein the mass of diatomaceous earth is 5 times the mass of polyaspartic acid, the mass of silane coupling agent KH550 is 0.08 times the mass of polyaspartic acid, and the mass of sodium dodecylbenzene sulfonate is 0.01 times the mass of polyaspartic acid, stirring at 40°C for 4 hours, filtering, washing and drying to obtain modified diatomaceous earth.

[0094] Polyaspartic acid was purchased from Shandong Yuanlian Chemical Co., Ltd.

[0095] The diatomaceous earth is a compound of diatomaceous earth with an average particle size of 2.5-5.5 μm, diatomaceous earth with an average particle size of 8-13 μm and diatomaceous earth with an average particle size of 15-18 μm, with a mass ratio of 4:3:1.

[0096] The preparation method of soybean straw ash is:

[0097] (1) washing the soybean straw, drying it, and crushing it to a length of 1-5 mm to obtain soybean straw powder;

[0098] (2) carbonizing the soybean straw powder, specifically: carbonizing at a pressure of 0.005 Pa, a temperature of 700° C., and a time of 320 min to obtain carbonized soybean straw;

[0099] (3) Add water to the carbonized soybean straw to make its humidity reach 45%, add composite bacteria and glucose and mix evenly, and ferment aerobically in a fermentation pit at 30°C for 50 hours to obtain soybean straw ash.

[0100] The composite bacteria in step (3) are Bacillus subtilis, Lactobacillus plantarum and Klebsiella in a mass ratio of 1:1.6:0.4.

[0101] Bacillus subtilis, SHMCC (SHBCC) D10486, Shanghai Baocang Microorganism Co., Ltd.

[0102] Lactobacillus plantarum, strain number: SHMCC (SHBCC) D24745, Shanghai Baocang Microbiology Co., Ltd.

[0103] Klebsiella pneumoniae, strain number: SHBCC D19134, Shanghai Collection of Biotechnology Center.

[0104] In the step (3), the mass of the composite bacteria accounts for 2% of the mass of the carbonized soybean straw, and the mass of the glucose is 150 times the mass of the composite bacteria.

[0105] The preparation method of the composite sewage treatment agent containing modified diatomaceous earth comprises the following steps:

[0106] (1) mixing polyaluminium chloride, sodium polyacrylate, ferric chloride and water to obtain a first mixed solution;

[0107] (2) mixing chitosan, bentonite, soybean straw ash, and modified diatomaceous earth to obtain a second mixture;

[0108] (3) Add the first mixed liquid to the second mixture, stir and mix until uniform, then add the remaining components, mix and stir until uniform, and obtain a composite sewage treatment agent containing modified diatomaceous earth.

[0109] Example 3

[0110] The difference between this embodiment and Example 1 is: a composite sewage treatment agent containing modified diatomaceous earth, comprising the following components in parts by mass: 12 parts of composite plant fermentation liquid, 17 parts of polyaluminum chloride, 8 parts of sodium polyacrylate, 6 parts of ferric chloride, 25 parts of chitosan, 5 parts of bentonite, 50 parts of soybean straw ash, 65 parts of modified diatomaceous earth, 6 parts of sodium dodecyl sulfate, 5 parts of potassium dihydrogen phosphate and 225 parts of water.

[0111] Comparative Example 1

[0112] The difference between this comparative example and Example 1 is that unmodified diatomaceous earth is used, and the diatomaceous earth is a compound of diatomaceous earth with an average particle size of 2.5-5.5 μm, diatomaceous earth with an average particle size of 8-13 μm, and diatomaceous earth with an average particle size of 15-18 μm, with a mass ratio of 3:2:1.

[0113] Comparative Example 2

[0114] The difference between this comparative example and Example 1 is that the preparation method of the modified diatomaceous earth is:

[0115] (1) adding polyaspartic acid to water 20 times its mass to obtain a polyaspartic acid solution;

[0116] (2) Adding diatomaceous earth, silane coupling agent KH550 and sodium dodecylbenzene sulfonate to the polyaspartic acid solution, wherein the mass of the diatomaceous earth is 7 times the mass of the polyaspartic acid, stirring at 45°C for 3.5 hours, filtering, washing and drying to obtain modified diatomaceous earth.

[0117] Comparative Example 3

[0118] The difference between this comparative example and Example 1 is that the composite bacteria are Bacillus subtilis, Lactobacillus plantarum and Klebsiella in a mass ratio of 1:1:1.

[0119] Comparative Example 4

[0120] The difference between this comparative example and Example 1 is that the composite bacteria are Bacillus subtilis, Rhodococcus and Pseudomonas stutzeri in a mass ratio of 1:1.4:0.5.

[0121] Bacillus subtilis, strain number: SHMCC (SHBCC) D10486, Shanghai Baocang Microbiology Co., Ltd.

[0122] Rhodococcus erythrorhizium, strain number: ACCC40100, China Center for Microbiological Culture Collection.

[0123] Pseudomonas stutzeri, strain number: ATCC17588, Ningbo Testo Biotechnology Co., Ltd.

[0124] Comparative Example 5

[0125] The difference between this comparative example and Example 1 is that the diatomaceous earth has an average particle size of 15-18 μm.

[0126] Comparative Example 6

[0127] The difference between this comparative example and Example 1 is that the diatomaceous earth has an average particle size of 2.5-5.5 μm.

[0128] Comparative Example 7

[0129] The difference between this comparative example and Example 1 is that the diatomaceous earth is a compound of diatomaceous earth with an average particle size of 2.5-5.5 μm, diatomaceous earth with an average particle size of 8-13 μm and diatomaceous earth with an average particle size of 15-18 μm, with a mass ratio of 1:1:1.

[0130] Comparative Example 8

[0131] The difference between this comparative example and Example 1 is that the diatomaceous earth is a mixture of diatomaceous earth with an average particle size of 2.5-5.5 μm and diatomaceous earth with an average particle size of 8-13 μm, with a mass ratio of 3:2.

[0132] Comparative Example 9

[0133] The difference between this comparative example and Example 1 is that the preparation method of the composite plant fermentation liquid is:

[0134] S1: Mix dried mint, dried orange peel, and dried reed with water in a mass ratio of 0.4:2.2:2:60, soak for 2 h, heat at 70°C for 10 h, and filter through a 0.25 μm filter membrane to obtain a filtrate;

[0135] S2: The filtrate, maltose, glucose and dry yeast were mixed in a mass ratio of 50:2:1:0.2, and the mixture was sealed and fermented at 30°C for 4 days to obtain a composite plant fermentation liquid.

[0136] Comparative Example 10

[0137] The difference between this comparative example and Example 1 is that the preparation method of the composite plant fermentation liquid is:

[0138] S1: Dry cattail, dry sedge, dry white ginger flower, dry water hyacinth, and coix lachryma-jobi were mixed with water in a mass ratio of 1:0.6:1.4:2.5:1.7:60, soaked for 1.5 h, heated at 73°C for 8 h, and filtered through a 0.25 μm filter membrane to obtain a filtrate;

[0139] S2: The filtrate, maltose, glucose and dry yeast were mixed in a mass ratio of 50:2:1:0.4, and the mixture was sealed and fermented at 30°C for 5 days to obtain a composite plant fermentation liquid.

[0140] Comparative Example 11

[0141] S1: Mix Robinia pseudoacacia leaves, dried mint, dried orange peel, centipede grass, and dried reed with water in a mass ratio of 1:5:6:0.1:0.5:60, soak for 2 h, heat at 70°C for 10 h, and filter through a 0.25 μm filter membrane to obtain a filtrate;

[0142] S2: The filtrate, maltose, glucose and dry yeast were mixed in a mass ratio of 50:2:1:0.2, and the mixture was sealed and fermented at 30°C for 4 days to obtain a composite plant fermentation liquid.

[0143] Performance Testing

[0144] 1. With reference to GB18918-2002, wastewater from a paper mill near the Liaohe Estuary Wetland was used as test water. The influent had a COD of 1900 mg / L, a BOD of 364 mg / L, SS of 1540 mg / L, lead ions of 1.38 mg / L, and a pH of 10.6. The test water, at a temperature of 5°C, was treated using the wastewater treatment agents of Examples 1-3 and Comparative Examples 1-11, respectively, at a dosage of 12 g / L. After treatment, the post-treatment contents and pH of the test water were measured.

[0145] Table 1 Test results (unit: mg / L)

[0146]

[0147]

[0148] The results show that the sewage treatment agents of Examples 1-3 have good comprehensive effects. When the components and preparation methods are changed, the decontamination effects decrease to varying degrees.

[0149] 2. The sewage treatment agents of Examples 1-3 and Comparative Examples 1-11 were placed in a light environment with a temperature of 38°C and a relative humidity of 65%. After storage for 240 days, sewage with a water temperature of 5°C, COD 1900 mg / L, BOD 364 mg / L, SS1540 mg / L, lead ions 1.38 mg / L, and pH 10.6 was selected. The dosage of the sewage treatment agent was 12 g / L, and the sewage treatment effect was measured again.

[0150] Table 2 Storage stability test results (unit: mg / L)

[0151]

[0152]

[0153] The results show that the wastewater treatment agent of Example 1 has good storage stability and remains basically unchanged, while the wastewater treatment agents of Examples 2-3 and Comparative Examples 1-11 have treatment effects that decrease to varying degrees after storage.

[0154] 3. Phthalates are a class of substances that may be introduced into the papermaking industry during processes such as coating and surface treatment. Dibutyl phthalate (DBP) is a common phthalate that has been shown to have potential ecotoxicity and disrupt the human endocrine system. Due to its high solubility and low volatility, DBP easily enters wastewater, and traditional wastewater treatment processes can be difficult to completely remove, leading to its discharge into the environment without proper treatment.

[0155] Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) that are highly toxic, persistent, and bioaccumulative, posing potential risks to the environment and human health. Although PCBs are not directly added to the papermaking process, some papermaking processes have historically used chlorine-containing chemicals for bleaching, which can generate PCBs or other chlorinated organic compounds during the reaction process. Furthermore, recycled waste paper may contain trace amounts of PCBs. Existing wastewater treatment agents often overlook the removal of PCBs from papermaking wastewater.

[0156] Wastewater from a paper mill near the Liaohe Estuary Wetland was used as test water. The test water, at a temperature of 5°C, was treated with the wastewater treatment agents described in Examples 1-3 and Comparative Examples 1-11, respectively, at a dosage of 12 g / L. After treatment, the DBP removal rate was calculated using the formula: (DBP amount before treatment - DBP amount after treatment) / DBP amount before treatment * 100%. The polychlorinated biphenyl (PCB) removal rate was also calculated using the formula: (PCB amount before treatment - PCB amount after treatment) / PCB amount before treatment * 100%. A commercially available product, purchased from Zibo Guangzheng Aluminum Salt Chemical Co., Ltd., was used as a control.

[0157] Table 3 Test results

[0158] DBP removal rate % PCBs removal rate (%) Example 1 88 85 Example 2 87 84 Example 3 86 82 Comparative Example 1 59 54 Comparative Example 2 81 79 Comparative Example 3 64 58 Comparative Example 4 62 57 Comparative Example 5 61 57 Comparative Example 6 63 56 Comparative Example 7 80 76 Comparative Example 8 77 70 Comparative Example 9 79 71 Comparative Example 10 82 80 Comparative Example 11 85 83 control group 52 49

[0159] The composite sewage treatment agents of Examples 1-3 of the present invention have high removal rates for DBP and PCBs, and have high adsorption and degradation effects, significantly outperforming commercially available products. Testing of the comparative example products showed that the decontamination effect was significantly worse after the limited technical solution was changed.

[0160] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A composite sewage treatment agent containing modified diatomaceous earth, characterized in that: The invention comprises the following components in parts by weight: 10-15 parts of composite plant fermentation liquid, 15-20 parts of polyaluminum chloride, 5-10 parts of sodium polyacrylate, 4-8 parts of ferric chloride, 15-25 parts of chitosan, 5-15 parts of bentonite, 40-50 parts of soybean straw ash, 65-75 parts of modified diatomaceous earth, 4-9 parts of sodium dodecyl sulfate, 3-8 parts of potassium dihydrogen phosphate and 220-230 parts of water; The preparation method of the composite plant fermentation liquid is as follows: S1: Mix Robinia pseudoacacia leaves, dried mint, dried orange peel, centipede grass, and dried reed with water, soak for 1-2 hours, heat at 70-75°C for 7-10 hours, and filter through a 0.25 μm filter membrane to obtain a filtrate; S2: Mix the filtrate, maltose, glucose, and dry yeast in a mass ratio of 50:2:1:0.2-0.5, and ferment in a sealed container at 30-35°C for 4-6 days to obtain a composite plant fermentation liquid; The preparation method of the modified diatomaceous earth is: (1) Mixing polyaspartic acid, aminobenzenesulfonic acid, and sodium hydroxide in a molar ratio of 1:0.4-0.8:0.2-0.6, adding the mixture to water 15-20 times the mass of the polyaspartic acid, and reacting the mixture at 500-1000 rpm for 1-2 hours under ice bath conditions to obtain a polyaspartic acid solution modified with sulfonic acid groups; (2) Adding diatomaceous earth, silane coupling agent KH550 and sodium dodecylbenzene sulfonate to the polyaspartic acid solution modified with sulfonic acid groups, wherein the mass of diatomaceous earth is 5-8 times the mass of polyaspartic acid, the mass of silane coupling agent KH550 is 0.05-0.08 times the mass of polyaspartic acid, and the mass of sodium dodecylbenzene sulfonate is 0.01-0.02 times the mass of polyaspartic acid, stirring at 40-50° C. for 3-4 hours, filtering, washing and drying to obtain modified diatomaceous earth.

2. The composite sewage treatment agent containing modified diatomaceous earth according to claim 1, characterized in that: The mass ratio of the locust leaves, dry mint, dry orange peel, centipede grass, dry reed and water is 1:0.4-0.9:1.2-1.7:2.2-2.7:1.5-2:

60.

3. The composite sewage treatment agent containing modified diatomaceous earth according to claim 1, characterized in that: The diatomaceous earth is a compound of diatomaceous earth with an average particle size of 2.5-5.5 μm, diatomaceous earth with an average particle size of 8-13 μm and diatomaceous earth with an average particle size of 15-18 μm, with a mass ratio of (3-5): (2-3):

1.

4. The composite sewage treatment agent containing modified diatomaceous earth according to claim 1, characterized in that The preparation method of soybean straw ash is: (1) washing the soybean straw, drying it, and crushing it to a length of 1-5 mm to obtain soybean straw powder; (2) carbonizing the soybean straw powder, specifically: carbonizing at a pressure of 0.005 Pa, a temperature of 700-800° C., and a time of 320-350 min to obtain carbonized soybean straw; (3) adding water to the carbonized soybean straw to make its humidity reach 40-45%, adding composite bacteria and glucose and mixing them evenly, and aerobically fermenting them in a fermentation pit at 30-35° C. for 50-60 hours to obtain soybean straw ash.

5. The composite sewage treatment agent containing modified diatomaceous earth according to claim 4, characterized in that: The composite bacteria in step (3) are Bacillus subtilis, Lactobacillus plantarum and Klebsiella in a mass ratio of 1:1.3-1.6:0.4-0.

7.

6. The composite sewage treatment agent containing modified diatomaceous earth according to claim 4, characterized in that: In the step (3), the mass of the composite bacteria accounts for 1-2% of the mass of the carbonized soybean straw, and the mass of the glucose is 100-150 times the mass of the composite bacteria.

7. The method for preparing a composite sewage treatment agent containing modified diatomaceous earth according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: (1) mixing polyaluminium chloride, sodium polyacrylate, ferric chloride and water to obtain a first mixed solution; (2) mixing chitosan, bentonite, soybean straw ash, and modified diatomaceous earth to obtain a second mixture; (3) Add the first mixed liquid to the second mixture, stir and mix until uniform, then add the remaining components, mix and stir until uniform, and obtain a composite sewage treatment agent containing modified diatomaceous earth.

8. Use of the composite sewage treatment agent containing modified diatomaceous earth according to any one of claims 1 to 6, characterized in that: The composite sewage treatment agent is used for treating papermaking wastewater.

9. The use according to claim 8, characterized in that When in use, add the composite sewage treatment agent containing modified diatomaceous earth into the sewage at an addition amount of 10-15g / L, stir and adsorb for 15-20 minutes, and filter.

10. The use according to claim 8, characterized in that The composite sewage treatment agent is used to treat papermaking wastewater below 10°C.

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