Method for treating fecal sewage

Abstract

The application discloses a kind of excrement sewage treatment method, belong to deodorization technical field, including the following steps: after excrement is dehydrated, filtrate is obtained, adjust the pH value of filtrate and maintain at ≤7, add chitosan oligosaccharide nonionic surfactant, then add composite microbial deodorant, after stirring uniformly, when ammonia gas concentration and hydrogen sulfide concentration in gas system are stable, obtain pretreated wastewater, add nonionic polyacrylamide to pretreated wastewater, and carry out flocculation precipitation;The composite microbial deodorant is attapulgite load microbial agent.Added composite microbial deodorant is attapulgite load microbial agent.The attapulgite load microbial agent can adsorb organic matter in filtrate to enrich organic matter, carrier adsorbs pollutants (amines, hydrogen sulfide, ammonia, etc.) to form high concentration micro area, accelerates microbial degradation kinetics, and improves the efficiency of microbial agent in treating filtrate.

Description

Technical Field

[0001] This invention belongs to the field of deodorization technology, specifically relating to a method for treating fecal wastewater. Background Technology

[0002] The filtrate from dehydrated feces contains high levels of organic matter and ammonia nitrogen, and also produces a large amount of foul-smelling gases. These gases are mainly caused by volatile substances produced from the putrefaction and decomposition of organic matter, such as amines, hydrogen sulfide, and ammonia. Specific examples include fishy odor [amines CH3NH2, (CH3)3N], ammonia odor [ammonia NH3], putrid meat odor [diamines NH2(CH2)4NH2], putrid egg odor (hydrogen sulfide H2S), putrid cabbage odor [organosulfur compounds (CH3)2S], and fecal odor [methyl indole C8H5NHCH3]. These strongly odorous volatile pollutants not only cause olfactory discomfort but also pose certain health risks.

[0003] In the treatment of fecal wastewater, commonly used deodorization methods include chemical oxidation, physical adsorption, and biological deodorization. Chemical oxidation has a fast reaction rate and can efficiently degrade odorous substances such as hydrogen sulfide and ammonia. However, oxidants such as chlorine and ozone are highly corrosive to equipment, requiring corrosion-resistant materials. Physical adsorption methods, such as using activated carbon and zeolite, can quickly remove various odorous substances. However, when the humidity of the wastewater and exhaust gas is high, the adsorption efficiency of activated carbon decreases (water molecules compete for adsorption sites), and thermal regeneration consumes high energy. Biological deodorization has low operating costs, mainly relying on microbial metabolism, and consumes less energy. However, because it requires the cultivation and acclimatization of microorganisms, the initial deodorization effect is unstable and greatly affected by environmental factors such as temperature, humidity, and pH. Unsuitable conditions can lead to a decrease in deodorization efficiency.

[0004] When treating malodorous gases produced by the filtrate after fecal dehydration, a single treatment method often fails to simultaneously achieve optimal deodorization efficiency and economic benefits. Traditional physical adsorption methods, while simple in equipment, suffer from problems such as easy adsorbent saturation and high regeneration costs; chemical oxidation methods offer rapid reactions but are expensive to operate and may generate secondary pollution; biological deodorization methods have lower operating costs but are sensitive to environmental conditions, have long start-up cycles, and are weak against shock loads. Furthermore, the physicochemical properties of different malodorous components vary significantly, making it difficult for a single technology to achieve efficient removal of pollutants. Summary of the Invention

[0005] The purpose of this invention is to provide a method for treating fecal wastewater to solve the problem of poor deodorization effect of fecal wastewater.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for treating fecal wastewater includes the following steps:

[0008] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7, and a chitosan oligosaccharide nonionic surfactant was added. Then, a compound microbial deodorizer was added and stirred evenly. When the concentrations of ammonia and hydrogen sulfide in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation. The compound microbial deodorizer was an attapulgite-loaded microbial agent.

[0009] In some specific embodiments, the mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide is 0.05-0.07:1.

[0010] In some specific implementations, the amount of nonionic polyacrylamide added per liter of pretreated wastewater is 1-3g.

[0011] In some specific implementations, 1.5-2g of compound microbial deodorant is added per liter of filtrate.

[0012] In some specific implementations, sodium bicarbonate or limestone is used to adjust the pH.

[0013] In some specific implementations, the microbial inoculants include lactic acid bacteria inoculants, Bacillus inoculants, and yeast inoculants.

[0014] In some specific embodiments, the attapulgite soil loaded with microbial inoculant is prepared through the following steps:

[0015] Add 1.5-5.5 kg of nitrogen source and 2-4 kg of carbon source to 30-36 kg of water, boil and cool, adjust the pH to 6, add microbial inoculant to obtain a compound bacterial solution, seal and ferment at room temperature for 12-24 hours, then add 40-60 kg of attapulgite soil to the compound bacterial solution, mix evenly, and dry to obtain attapulgite soil loaded with microbial inoculant.

[0016] In some specific embodiments, the compound bacterial solution contains bacteria with a count of 1-3 × 10⁻⁶. 8 Lactobacillus acidophilus CFU / mL; including bacteria with counts of 1-3 × 10⁻⁶. 8 Bacillus megaterium with a CFU / mL count; including those with a bacterial count of 7-8 × 10⁶. 8 CFU / mL of Candida albicans.

[0017] In some specific embodiments, the chitosan oligosaccharide surfactant is prepared by the following steps:

[0018] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1g:10mL, triethylamine was added and stirred for 5-6 hours, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40℃, and the reaction was continued to be stirred for 10-16 hours. After the reaction was completed, acetone was added to precipitate the product, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant.

[0019] In some specific embodiments, the fatty acyl chloride is one of decanoyl chloride and heptanoyl chloride; the average molecular weight of chitosan oligosaccharide is 1000; the ratio of fatty acyl chloride to chitosan oligosaccharide is 0.01-0.02 mol: 4 g.

[0020] The beneficial effects of this invention are:

[0021] This invention provides a method for treating fecal wastewater, which improves the deodorization effect of fecal wastewater through pH adjustment, the use of chitosan oligosaccharide nonionic surfactants, and a composite microbial deodorizing agent. Adjusting the pH value allows volatile organic compounds to be better stabilized in the filtrate obtained after fecal dehydration, reducing odor emissions and facilitating subsequent treatment of these organic compounds by the composite microbial deodorizing agent, thus improving treatment efficiency. The chitosan oligosaccharide surfactant added in this invention reduces the surface tension of water, making pollutants easier to disperse and improving the stability of volatile gases in water, thereby enhancing the treatment effect of the microbial agent. The composite microbial deodorizing agent added in this invention is an attapulgite-supported microbial agent. This attapulgite-supported microbial agent can adsorb and enrich organic matter in the filtrate. The carrier adsorbs pollutants (amines, hydrogen sulfide, ammonia, etc.) to form high-concentration micro-regions, accelerating microbial degradation kinetics and improving the efficiency of the microbial agent in treating the filtrate. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] The following is a detailed description of a fecal sewage treatment method according to an embodiment of this application.

[0024] This application provides a method for treating fecal wastewater, including the following steps:

[0025] After dehydrating the feces, the filtrate is obtained. The pH of the filtrate is adjusted to ≤7, and chitosan oligosaccharide nonionic surfactant is added. Then, a compound microbial deodorizer is added and stirred evenly. When the concentrations of ammonia and hydrogen sulfide in the gas system are stable, pretreated wastewater is obtained. Nonionic polyacrylamide is added to the pretreated wastewater for flocculation and sedimentation to obtain treated wastewater.

[0026] In some specific embodiments, the mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide is 0.05-0.07:1.

[0027] In some specific embodiments, the amount of nonionic polyacrylamide added per liter of pretreated wastewater is 1-3g.

[0028] In some specific embodiments, 1.5-2g of compound microbial deodorant is added per liter of filtrate.

[0029] In some specific embodiments, sodium bicarbonate or limestone is used to adjust the pH. If the pH is too high, it will generate a large amount of ammonia pollution, and then a rapid drop in pH will lead to continued hydrogen sulfide emissions. By adding sodium bicarbonate to maintain a pH of 6 < ≤ 7, NH4+ is produced. + The volatility of ammonium ions and H2S (hydrogen sulfide) is significantly reduced. At this point, the volatility of NH4+ is significantly reduced. + It mainly exists in ionic form, while H2S mainly exists as HS-H2S. - (hydrosulfate ions) and S 2- It exists in the form of (sulfide ions), thereby reducing odor emissions. This provides a suitable environment for subsequent treatment with compound microbial deodorizing agents.

[0030] In some specific embodiments, the composite microbial deodorizer is an attapulgite-loaded microbial agent; the microbial agent includes lactic acid bacteria, Bacillus, and yeast.

[0031] In some specific embodiments, the attapulgite soil loaded with microbial inoculant is prepared through the following steps:

[0032] Add 1.5-5.5 kg of nitrogen source and 2-4 kg of carbon source to 30-36 kg of water, boil, cool, adjust the pH to 6, add microbial inoculant to obtain a compound bacterial solution, ferment at room temperature in a sealed container for 12-24 hours, then add 40-60 kg of attapulgite soil to the compound bacterial solution, mix thoroughly, and dry to obtain attapulgite soil-loaded microbial inoculant. The compound bacterial solution contains 1-3 × 10⁻⁶ bacteria. 8 Lactobacillus acidophilus CFU / mL; including bacteria with counts of 1-3 × 10⁻⁶. 8 Bacillus megaterium with a CFU / mL count; including those with a bacterial count of 7-8 × 10⁶. 8 CFU / mL of Candida albicans. Due to the extremely strong adsorption properties of attapulgite, it can not only serve as a carrier for microbial agents, improving their adaptability and stability in complex environments, but also adsorb organic matter in the filtrate, enriching it. The carrier adsorbs pollutants (amines, hydrogen sulfide, ammonia, etc.) to form high-concentration micro-regions, accelerating microbial degradation kinetics and improving the efficiency of microbial agents in treating the filtrate.

[0033] Preferably, the lactic acid bacteria, Bacillus, and yeast inoculants undergo pre-acclimatization treatment. The inoculants are pre-exposed to the filtrate obtained after fecal dehydration, allowing them to better adapt to the filtrate environment and thus improving their growth, metabolism, and functional performance in the filtrate. For example, the filtrate from fecal dehydration can be added to a culture medium at a ratio of 1:10 to simulate the fecal environment. Each bacterium can be acclimatized individually or mixed together. During the acclimatization process, the growth of the microorganisms and changes in their metabolites are monitored regularly, and the composition of the culture medium is adjusted as needed.

[0034] In some specific embodiments, the chitosan oligosaccharide surfactant is prepared by the following steps:

[0035] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1g:10mL, and triethylamine was added and stirred for 5-6 hours. Fatty acyl chloride was then added under ice-water bath conditions, and the temperature was raised to 40℃. The reaction was continued with stirring for 10-16 hours. After the reaction was complete, acetone was added to precipitate the product, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant. The chitosan oligosaccharide surfactant is modified from chitosan oligosaccharide. Its main component, chitosan oligosaccharide, is a natural biopolymer with good biodegradability, making it more environmentally friendly. Furthermore, the chitosan oligosaccharide surfactant can reduce the surface tension of water, making pollutants easier to disperse and improving the stability of volatile gases in water, thereby enhancing the treatment effect of microbial agents. In addition, the chitosan oligosaccharide surfactant is a nonionic surfactant, and both nonionic polyacrylamide and nonionic polyacrylamide have good hydrophilicity and adsorption properties. The subsequent addition of nonionic polyacrylamide can significantly improve the flocculation effect and accelerate the sedimentation of suspended particles.

[0036] In some specific embodiments, the fatty acyl chloride is one of decanoyl chloride and heptanoyl chloride. The long alkyl chain of the fatty acyl chloride can enhance hydrophobicity, but excessively long alkyl chains can lead to poor solubility, reduced surface activity, decreased solubilizing ability, and poor biodegradability. Decanoyl chloride and heptanoyl chloride are preferred in this invention. The average molecular weight of the chitosan oligosaccharide is 1000; the ratio of fatty acyl chloride to chitosan oligosaccharide is 0.01-0.02 mol: 4 g.

[0037] The following is a detailed description with reference to specific examples.

[0038] Example 1

[0039] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0040] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using sodium bicarbonate. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.05:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 1g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0041] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0042] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent; the attapulgite soil-loaded microbial agent is prepared through the following steps:

[0043] 3 kg of soybean meal, 0.5 kg of yeast extract, and 4 kg of glucose were added to 30 kg of water, boiled, and cooled. Sodium carbonate was added to adjust the pH to 6. Microbial inoculants were then added to obtain a compound bacterial solution. After fermentation at room temperature in a sealed container for 12 hours, 40 kg of attapulgite soil was added to the compound bacterial solution and mixed thoroughly. The mixture was then dried to obtain attapulgite soil-loaded microbial inoculants. The compound bacterial solution contained 1 × 10⁻⁶ bacteria. 8 Lactobacillus acidophilus CFU / mL; including Lactobacillus with a bacterial count of 1×10⁻⁶. 8 Bacillus megaterium with a CFU / mL count; including those with a bacterial count of 7 × 10⁶. 8 CFU / mL of Candida albicans.

[0044] Example 2

[0045] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0046] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using sodium bicarbonate. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, and once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.06:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 1g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0047] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0048] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0049] Example 3

[0050] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0051] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using sodium bicarbonate. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, and once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.07:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 1g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0052] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0053] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0054] Example 4

[0055] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0056] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using sodium bicarbonate. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.05:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 2g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0057] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0058] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0059] Example 5

[0060] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0061] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using sodium bicarbonate. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, and once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.05:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 3g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0062] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0063] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0064] Example 6

[0065] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0066] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using sodium bicarbonate. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 2g per liter of filtrate. After thorough stirring, and once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.05:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 1g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0067] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0068] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0069] Example 7

[0070] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0071] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using limestone. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, and once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.05:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 1g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0072] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was decanoyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0073] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0074] Example 8

[0075] This embodiment provides a method for treating fecal wastewater, including the following steps:

[0076] After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to ≤7 using limestone. A chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer at a concentration of 1.5g per liter of filtrate. After thorough stirring, and once the ammonia and hydrogen sulfide concentrations in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation, yielding treated wastewater. The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide was 0.05:1. The amount of nonionic polyacrylamide added per liter of pretreated wastewater was 1g. The chitosan oligosaccharide surfactant was prepared through the following steps:

[0077] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued to be stirred for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant; the fatty acyl chloride was heptanyl chloride; the average molecular weight of chitosan oligosaccharide was 1000; and the ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0078] The composite microbial deodorizer is an attapulgite soil-loaded microbial agent, as in Example 1.

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 1 is that no chitosan oligosaccharide nonionic surfactant is added, while the other raw materials and preparation process remain the same as in Example 1.

[0081] Comparative Example 2

[0082] The difference between this comparative example and Example 1 lies in the preparation process of the chitosan oligosaccharide surfactant. The chitosan oligosaccharide surfactant is prepared through the following steps:

[0083] Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1 g: 10 mL, triethylamine was added and stirred for 5 h, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40 °C, and the reaction was continued with stirring for 10 h. After the reaction was completed, acetone was added to precipitate the mixture, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide surfactant. The fatty acyl chloride was lauroyl chloride. The average molecular weight of the chitosan oligosaccharide was 1000. The ratio of fatty acyl chloride to chitosan oligosaccharide was 0.02 mol: 4 g.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 1 is that the compound microbial deodorizer is different. Specifically, the compound microbial agent is not loaded; instead, 1.5g of the compound bacterial liquid fermented at room temperature for 12 hours as described in Example 1 is directly added to each liter of filtrate. The remaining raw materials and preparation process are the same as in Example 1.

[0086] Comparative Example 4

[0087] The difference between this comparative example and Example 1 is that the composite microbial deodorizer is different; specifically, attapulgite clay is replaced with ceramic particles. The other raw materials and preparation process remain the same as in Example 1.

[0088] After 7 days, the concentrations of ammonia and hydrogen sulfide in the environment stabilized. The ammonia removal rate, hydrogen sulfide removal rate, and suspended solids content corresponding to the methods in Examples 1-8 and Comparative Examples 1-3 were recorded after 7 days. The content of ammonia and hydrogen sulfide gases was tested using an HF-900 gas chromatograph, and the corresponding removal rates were calculated: Ammonia removal rate = (Control group release amount - Experimental group release amount) / Control group release amount × 100%; Hydrogen sulfide removal rate = (Control group release amount - Experimental group release amount) / Control group release amount × 100%. The control group consisted of the same water sample but without any treatment, containing the concentrations of ammonia and hydrogen sulfide. The results are shown in Table 1 below.

[0089] Table 1

[0090] project Ammonia removal rate / % Hydrogen sulfide removal rate / % Suspended solids content (mg / L) Example 1 81.50 78.32 Less than 1 Example 2 83.33 80.21 Less than 1 Example 3 83.46 80.22 Less than 1 Example 4 81.34 78.57 Less than 1 Example 5 81.66 78.48 Less than 1 Example 6 85.51 82.24 Less than 1 Example 7 81.12 78.15 Less than 1 Example 8 80.24 77.88 Less than 1 Comparative Example 1 76.23 73.30 4.26 Comparative Example 2 77.49 74.85 Less than 1 Comparative Example 3 74.75 71.57 6.39 Comparative Example 4 79.14 76.36 2.33

[0091] As shown in Table 1, the method provided in this invention achieves a removal rate of up to 80% for ammonia and hydrogen sulfide in the filtrate obtained after dehydrating feces, and can also reduce the suspended solids content in the filtrate. A comparison of Example 1 and Comparative Examples 1-4 shows that the absence of chitosan oligosaccharide surfactants and the use of supported composite microbial deodorizers affects the enrichment of organic matter. Different types of chitosan oligosaccharide surfactants and carriers also affect the enrichment of organic matter, failing to form high-concentration micro-zones, leading to a decrease in the efficiency of microbial agents in treating the filtrate.

[0092] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0093] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for treating fecal wastewater, characterized in that, Includes the following steps: After dehydrating the feces, a filtrate was obtained. The pH of the filtrate was adjusted to maintain at 6 < pH ≤ 7. Chitosan oligosaccharide nonionic surfactant was added, followed by a compound microbial deodorizer. After stirring evenly, when the concentrations of ammonia and hydrogen sulfide in the gas system stabilized, pretreated wastewater was obtained. Nonionic polyacrylamide was added to the pretreated wastewater for flocculation and sedimentation. The compound microbial deodorizer was an attapulgite-loaded microbial agent.

2. The method for treating fecal wastewater according to claim 1, characterized in that, The mass ratio of chitosan oligosaccharide nonionic surfactant to nonionic polyacrylamide is 0.05-0.07:

1.

3. The method for treating fecal wastewater according to claim 1, characterized in that, The dosage of nonionic polyacrylamide added per liter of pretreated wastewater is 1-3g.

4. The method for treating fecal wastewater according to claim 1, characterized in that, Add 1.5-2g of compound microbial deodorizer per liter of filtrate.

5. The method for treating fecal wastewater according to claim 1, characterized in that, Use sodium bicarbonate or limestone to adjust the pH.

6. The method for treating fecal wastewater according to claim 1, characterized in that, Microbial inoculants include lactic acid bacteria inoculants, Bacillus inoculants, and yeast inoculants.

7. The method for treating fecal wastewater according to claim 1, characterized in that, The attapulgite soil-loaded microbial inoculant is prepared through the following steps: Add 1.5-5.5 kg of nitrogen source and 2-4 kg of carbon source to 30-36 kg of water, boil and cool, adjust the pH to 6, add microbial inoculant to obtain a compound bacterial solution, seal and ferment at room temperature for 12-24 hours, then add 40-60 kg of attapulgite soil to the compound bacterial solution, mix evenly, and dry to obtain attapulgite soil loaded with microbial inoculant.

8. A method for treating fecal wastewater according to claim 7, characterized in that, The compound bacterial solution contains bacteria with a count of 1-3 × 10⁻⁶. 8 Lactobacillus acidophilus CFU / mL; including bacteria with counts of 1-3 × 10⁻⁶. 8 Bacillus megaterium with a CFU / mL count; including those with a bacterial count of 7-8 × 10⁶. 8 CFU / mL of Candida albicans.

9. A method for treating fecal wastewater according to claim 1, characterized in that, The chitosan oligosaccharide nonionic surfactant is prepared by the following steps: Chitosan oligosaccharide and isopropanol were mixed at a ratio of 1g:10mL, triethylamine was added and stirred for 5-6 hours, fatty acyl chloride was added under ice-water bath conditions, the temperature was raised to 40℃, and the reaction was continued to be stirred for 10-16 hours. After the reaction was completed, acetone was added to precipitate the product, which was then washed with ethanol and dried under vacuum to obtain the chitosan oligosaccharide nonionic surfactant.

10. A method for treating fecal wastewater according to claim 9, characterized in that, Fatty acyl chloride is one of decanoyl chloride and heptanoyl chloride; the average molecular weight of chitosan oligosaccharide is 1000; the ratio of fatty acyl chloride to chitosan oligosaccharide is 0.01-0.02 mol: 4 g.