A kitchen waste stench pollution source control method

Abstract

The application discloses a kind of kitchen garbage stench pollution source control method.This method is directly added to the kitchen garbage that has not been treated Compound deodorization reagent, stir evenly, stand 1~50h, obtain;The Compound deodorization reagent includes the following mass percentage components:45~60% potassium monopersulfate compound salt, 3~9% polyvinyl alcohol, 5~15% polyvinylpyrrolidone, the rest is pure water.This method is based on the synergistic effect of Compound deodorization reagent and kitchen garbage, using the environmental characteristics of high salt, rich in organic matter and acidic spoilage of kitchen garbage, and the strong oxidizing substance of superoxide class is generated by reaction with compound reagent, oxidize and degrade the reducing stench substance in kitchen garbage, especially the sulfide with strong irritation, and improve the anaerobic environment inside kitchen garbage, reduce the amount of stench substance released due to anaerobic microbial metabolism, so as to realize the source of kitchen garbage stench pollution control.

Description

Technical Field

[0001] This invention relates to a method for treating kitchen waste, specifically a method for controlling the source of odor pollution from kitchen waste, belonging to the field of kitchen waste pollution and treatment technology. Background Technology

[0002] Food waste is mainly composed of organic matter such as starch, dietary fiber, and animal fat, and is characterized by high moisture, high oil, high salt, and easy putrefaction and acidification. The initial stages of food waste harmless treatment often employ a decentralized collection, transportation, and centralized processing method. From the time food waste is dumped, through collection and transportation, to its harmless treatment phase, it often takes 1-3 days. During this process, the environment is predominantly anaerobic, where microorganisms decompose the easily perishable organic matter, releasing large amounts of complex gaseous products, such as hydrogen sulfide, thiols, sulfides, and most reducing substances, including small-molecule organic acids. These substances mix together to form foul-smelling gases, causing unpleasantness and damaging the living environment, resulting in odor pollution and affecting the lives of surrounding residents.

[0003] Currently, the methods for controlling odor pollution throughout the entire process of harmless treatment of food waste are mainly divided into three aspects: source reduction, process control, and end-of-pipe removal. End-of-pipe removal technologies mainly include physical, chemical, and biological methods. These methods utilize certain characteristics and properties of odors, based on physical, chemical, and biological principles, to adsorb, transfer, and decompose odors into odorless substances. Process control methods involve physical isolation and negative pressure collection. This primarily involves implementing closed-loop mechanical operations during the harmless treatment of food waste to reduce the exposed surface of odor sources and the disorderly dispersion of odorous gases. Appropriate equipment is used to collect odorous substances in an orderly manner, thereby reducing unorganized odor pollution. Source reduction methods mainly involve the impact application of chemicals with antibacterial or bactericidal functions to reduce microbial metabolic activity. Another approach is to use film-forming products to form a physical film on the surface of food waste to block the diffusion of odorous substances, achieving source reduction and control.

[0004] Methods for odor pollution control mainly focus on process control and end-of-pipe removal. However, limitations in application scope, usage environment, land area, and cost mean that while these methods can effectively control odor pollution and reduce its impact within a certain range, their effectiveness is less than ideal at the source of food waste, such as collection and transportation. Existing source control methods are mostly single-function products that rely on physical isolation through film-forming products and microbial disinfection and inhibition. These methods suffer from short duration of action and are highly susceptible to external environmental influences, failing to effectively regulate odor pollution at the source of food waste. Therefore, the market urgently needs to develop a method to control odor pollution from food waste at its source, achieving control and reduction of odor pollution at the source throughout the entire process of harmless treatment of food waste. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for controlling odor pollution from kitchen waste at its source. This method is based on the synergistic effect of a compound deodorizing agent and kitchen waste. It utilizes the environmental characteristics of kitchen waste, such as high salt content, rich organic matter, and acidic decay, to react with the compound agent to produce superoxide-like strong oxidizing substances. These substances oxidize and degrade reducing odorous substances in the kitchen waste, especially highly irritating sulfides, and improve the anaerobic environment inside the kitchen waste, reducing the odorous substances released by anaerobic microorganisms. This achieves source control of odor pollution from kitchen waste.

[0006] To achieve the above technical objectives, this invention provides a method for controlling odor pollution sources from kitchen waste, which involves directly adding a compound deodorizing agent to untreated kitchen waste, stirring it evenly, and letting it stand for 1 to 50 hours to obtain the product.

[0007] The composite deodorizing agent comprises the following components in the following mass ratio: 45-60 parts potassium persulfate compound salt, 3-9 parts polyvinyl alcohol and 5-15 parts polyvinylpyrrolidone.

[0008] The kitchen waste is high in salt and rich in organic matter, with a pH value of 2-5, a chloride content of 0.5-1.5%, an odor concentration of ≥1000, and a sulfide content of ≥3.5ppm; the mass ratio of the compound deodorizing agent to the kitchen waste is 1:100-300.

[0009] The food waste treatment method provided by this invention is a source-based treatment method. Food waste requires no pretreatment; the compound deodorizing agent utilizes the high-salt, acidic, and reducing odorous substances in the food waste to react with it, releasing strong oxidizing substances. The oxidation-reduction process of the reducing odorous substances is as follows:

[0010] 1. H2S + O2 → H2SO4

[0011] 2. (CH3)2S + O2 → H2SO4 + CO2 + H2O

[0012] 3. (CH3)2S2+O2→H2SO4+CO2+H2O. This method addresses the issue at its source, eliminating the need for additional strong oxidants and effectively degrading odorous substances in food waste.

[0013] As a preferred embodiment, the preparation process of the composite deodorizing agent is as follows: after mixing polyvinyl alcohol, polyvinylpyrrolidone and water evenly, potassium persulfate composite salt is slowly added and fully mixed, and then dried, ground and sieved in sequence to obtain the final product.

[0014] As a preferred embodiment, the composite deodorizing agent is dried by baking, with the following conditions: temperature of 50–65°C and time of 1–2 hours. More preferably, the drying temperature is 55°C and the time is 1.5 hours.

[0015] As a preferred embodiment, the particle size of the composite deodorizing agent is 50-100 mesh.

[0016] As a preferred embodiment, the composite deodorizing agent comprises the following components in the indicated mass ratio: 50-60 parts potassium persulfate composite salt, 6-9 parts polyvinyl alcohol, and 9-12 parts polyvinylpyrrolidone. More preferably, the composite deodorizing agent comprises the following components in the indicated mass ratio: 55 parts potassium persulfate composite salt, 6 parts polyvinyl alcohol, and 10 parts polyvinylpyrrolidone.

[0017] The composition and proportion of the compound deodorizing agent must strictly adhere to the above requirements. Potassium persulfate compound salt can undergo a chain reaction under acidic conditions, using chloride ions as a catalyst, to produce strong oxides such as hypochlorite, hydroxyl radicals, and reactive oxygen species. Polyvinyl alcohol and polyvinylpyrrolidone are both water-soluble polymers with excellent encapsulation properties, which can encapsulate the potassium persulfate compound salt, thus preventing a rapid reaction between the potassium persulfate compound salt and reducing substances in kitchen waste, which would hinder long-term control of odor sources. If the proportion of potassium persulfate compound salt is too high, the film-forming effect will be too weak, and the reaction too violent. If the proportion is too low, the oxide content in the kitchen waste will be too low, failing to inhibit the reproduction of anaerobic microorganisms and the generation of odorous substances, thus failing to achieve the purpose of source deodorization. Therefore, only within the component and proportion range required by this invention can the compound deodorizing agent achieve its intended effect.

[0018] As a preferred embodiment, when the chloride content of the kitchen waste is ≤0.8%, chloride is added to adjust the chloride content of the kitchen waste to 0.8-1.5%.

[0019] As a preferred embodiment, the chloride is at least one of sodium chloride, potassium chloride, hydrochloric acid, calcium chloride, and phosphorus chloride.

[0020] As a preferred embodiment, the food waste has a pH value of 2-4, a chloride content of 0.8-1.1%, an odor concentration of ≥1200, and a sulfide content of ≥3.8ppm.

[0021] As a preferred embodiment, the mass ratio of the compound deodorizing agent to the kitchen waste is 1:100-300; the kitchen waste with the added compound deodorizing agent is left to stand in air for 12-48 hours.

[0022] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0023] 1) The control method provided by this invention is based on the synergistic effect of compound deodorizing agents and kitchen waste. It utilizes the characteristics of kitchen waste being high in salt, rich in organic matter, and acidic in its decay to react with compound agents to produce superoxide-like strong oxidizing substances, which oxidize and degrade the reducing odorous substances in kitchen waste, especially the highly irritating sulfides, thereby achieving source-based treatment and control of odor pollution from kitchen waste.

[0024] 2) In the technical solution provided by the present invention, by strictly controlling the content of each component in the compound deodorizing agent, the active oxygen content in the kitchen waste is greatly increased in the specific environment of the kitchen waste. On the one hand, it degrades the reducing malodorous substances in the kitchen waste, and on the other hand, it can improve the anaerobic environment in the kitchen waste, prevent more malodorous substances from being produced by the metabolism of anaerobic microorganisms, and facilitate subsequent treatment.

[0025] 3) In the technical solution provided by the present invention, there is no need to directly add strong oxidants to the kitchen waste. The strong oxides are formed by the synergistic effect of the compound deodorizing agent and the kitchen waste. The strong oxides are generated based on the specific environment of the kitchen waste with specific high salt, acid and reducing odor substances. Therefore, when the odor substances are significantly degraded, the strong oxides will no longer be generated in the system, thereby avoiding the over-oxidation of the system. The overall treatment process is mild and has strong sustainability.

[0026] 4) The odor control method for reducing food waste at the source provided by this invention, compared with process control and end-of-pipe removal methods, regulates and controls the odor pollution of food waste at an earlier stage, effectively reducing the scope and degree of odor pollution. It also features less interference from external environmental factors, simple operation, low equipment investment, and no secondary pollution. Detailed Implementation

[0027] To better understand this invention, the following specific embodiments further illustrate its content. A composite agent was prepared using the above-described method for preparing a source control agent for odor pollution from kitchen waste, and applied to an experiment controlling the source of odor pollution from kitchen waste. Under certain conditions, the source control effect on odor pollution from kitchen waste was investigated. Details are as follows:

[0028] Detection method:

[0029] (1) The concentrations of hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide in sulfur-containing odorous substances were detected by gas chromatography (GB / T14678-1993) for the determination of hydrogen sulfide, dimethyl sulfide and dimethyl disulfide in air quality.

[0030] (2) The odor concentration was detected by the "Three-point comparison odor bag method for determination of odor in ambient air and exhaust gas" (HJ 1262-2022).

[0031] (3) The chloride content in kitchen waste was detected by the argentometric method in "Determination of Chloride in Food" (GB5009.44-2016).

[0032] (4) The pH value of kitchen waste was detected by electrode method in "Determination of pH value in food" (GB5009.237-2016).

[0033] (5) The oxidation-reduction potential of kitchen waste was detected using the "Determination of Soil Oxidation-Reduction Potential by Potential Method" (HJ746-2015).

[0034] The preparation process of the drug:

[0035] (1) The present invention provides a composite deodorizing agent, wherein the components and their proportions are as follows:

[0036] Components Proportion potassium persulfate complex salt 55 Polyvinyl alcohol 6 Polyvinylpyrrolidone 10 pure water 29

[0037] (2) First, mix polyvinyl alcohol, polyvinylpyrrolidone and pure water evenly, then mix potassium persulfate compound salt evenly with it, dry, grind and sieve to obtain 50-100 mesh granules.

[0038] Example 1

[0039] Take 25 kg of kitchen waste from a company's workshop. Its pH value is 3.5 and its chloride content is 0.86%. Weigh out 100 g of the reagent, add it to the kitchen waste, and stir well.

[0040]

[0041] Example 2

[0042] Take 25 kg of kitchen waste from a company's workshop. Its pH value is 3.5 and its chloride content is 0.86%. Weigh 200 g of the reagent, add it to the kitchen waste, and stir well.

[0043]

[0044] Example 3

[0045] Take 25kg of kitchen waste from a company's workshop. Its pH value is 3.5 and its chloride content is 0.86%. Adjust the chloride content to 1.06% with edible salt. Weigh out 100g of the reagent, add it to the kitchen waste, and stir well.

[0046]

[0047] Example 4

[0048] Take 25kg of kitchen waste from a company's workshop. Its pH value is 3.5. Adjust the pH value to 4.5 with caustic soda flakes. The chloride content is 0.86%. Weigh 100g of the agent and add it to the kitchen waste. Stir well.

[0049]

[0050] Comparative Example 1

[0051] 25 kg of kitchen waste from a company's workshop, with a pH value of 3.5 and a chloride content of 0.86%, was collected and tested simultaneously in the same environment without any treatment.

[0052]

[0053] Comparative Example 2

[0054] Take 25 kg of kitchen waste from a company's workshop. Its pH value is 6.0 and its chloride content is 0.47%. Weigh out 100 g of the reagent, add it to the kitchen waste, and stir well.

[0055]

[0056]

[0057] As demonstrated in Examples 1-3 and Comparative Example 1, the composite deodorizing agent provided by this invention can effectively degrade and inhibit the continuous generation of malodorous substances in kitchen waste, and effectively degrade reducing sulfides. Furthermore, as shown in Examples 1 and 2, increasing the dosage of the agent results in stronger, faster, and longer-lasting control of malodorous pollution. Examples 1 and 3 show that increasing the chloride content in the system effectively accelerates the agent's action rate, leading to faster control of malodorous pollution sources. Examples 1 and 4 demonstrate that the pH of the system significantly affects the agent's effectiveness; as the pH increases, the agent's action rate slows down considerably, and its inhibitory effect on malodorous substances decreases. Examples 1 and Comparative Example 1 show that the composite deodorizing agent provided by this invention can improve the internal anaerobic environment of kitchen waste, with its oxidation-reduction potential gradually increasing after addition, thereby effectively inhibiting the metabolism of anaerobic microorganisms in kitchen waste and reducing the generation of malodorous substances.

[0058] As can be seen from Examples 1-3 and Comparative Example 2, the various physicochemical parameters of kitchen waste have a significant impact on the source odor treatment effect. When the pH and chloride content of kitchen waste are not within the required range, the activity of the agent will be greatly reduced. Furthermore, due to the decrease in the content of odorous substances in kitchen waste, the synergistic effect between the compound agent and kitchen waste is further reduced, and strong oxidizing substances cannot be generated. As a result, as the treatment time changes from 1 to 12 hours, not only is the decrease in odorous substances in kitchen waste not inhibited, but more odorous substances are generated. Furthermore, the data from Comparative Example 2 also shows that the growth rate of odorous substances gradually decreased from 1 to 12 hours after drug administration. From 1 to 6 hours, the increase in odorous substances was 704, and from 6 to 12 hours, the increase was 582. After 12 hours of drug administration, the odorous substances in the kitchen waste decreased. This is because, over time, the putrefaction of organic matter in the kitchen waste led to acidification, which changed the pH and salinity of the system, reaching the threshold for activating the compound agent, thus reacting with and inhibiting the odorous substances. A comparison of the odorous substance content of Comparative Example 2 and Comparative Example 1 at 48 hours also shows that the odorous substance content in Comparative Example 2 was around 1701, while the odorous substance content in Comparative Example 1 was as high as 20451 at 48 hours.

[0059] As can be seen from the above embodiments and comparative examples, only by utilizing the synergistic effect of kitchen waste and compound agents within the scope provided by this invention can the source treatment of odorous substances in kitchen waste be achieved and the odor pollution from kitchen waste be controlled.

Claims

1. A method for controlling odor pollution sources from kitchen waste, characterized in that: A composite deodorizing agent is directly added to untreated kitchen waste, stirred uniformly, and left to stand for 1-50 h to obtain the kitchen waste. The composite deodorizing agent comprises the following components in a mass ratio: 45-65 parts of potassium monopersulfate compound salt, 3-9 parts of polyvinyl alcohol, and 5-15 parts of polyvinylpyrrolidone. The kitchen waste is high-salt organic-rich waste, has a pH value of 2-5, a chloride content of 0.5-1.5%, an odor concentration of ≥1000, and a sulfide content of ≥3.5 ppm; the mass ratio of the composite deodorizing agent to the kitchen waste is 1:100-300. When the chloride content of the kitchen waste is ≤0.8%, chloride is added to adjust the chloride content of the kitchen waste to 0.8-1.5%.

2. The kitchen waste odor pollution source control method according to claim 1, characterized in that: The preparation process of the composite deodorizing agent is as follows: polyvinyl alcohol, polyvinylpyrrolidone, and water are uniformly mixed, and then potassium monopersulfate compound salt is slowly added and fully mixed, and the mixture is sequentially dried and ground and sieved to obtain the composite deodorizing agent.

3. The method for controlling odor pollution sources from kitchen waste according to claim 2, characterized in that: The drying method of the composite deodorizing agent is oven drying, and the conditions are as follows: a temperature of 50-65℃ and a time of 1-2 h; the particle size of the composite deodorizing agent is 50-100 mesh.

4. The kitchen waste odor pollution source control method according to claim 1, characterized in that: The composite deodorizing agent comprises the following components in a mass ratio: 50-60 parts of potassium monopersulfate compound salt, 6-9 parts of polyvinyl alcohol, and 9-12 parts of polyvinylpyrrolidone.

5. The kitchen waste odor pollution source control method according to claim 1, characterized in that: The chloride is at least one of sodium chloride, potassium chloride, hydrochloric acid, and calcium chloride.

6. The kitchen waste odor pollution source control method according to claim 1, characterized in that: The kitchen waste has a pH value of 2-4, a chloride content of 0.8-1.1%, an odor concentration of ≥1200, and a sulfide content of ≥3.8 ppm.

7. The kitchen waste odor pollution source control method according to claim 1, characterized in that: The mass ratio of the composite deodorizing agent to the kitchen waste is 1:100-300; the kitchen waste to which the composite deodorizing agent is added is left to stand in an air atmosphere for 12-48 h.

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