Treatment method of multi-source organic waste

Abstract

The invention belongs to the field of organic waste treatment, and particularly relates to a multi-source organic waste treatment method. The treatment method comprises the following steps: separating solid-phase residues and leachate from the sorted kitchen waste; crushing the agricultural and forestry wastes, stirring and crushing the solid-phase residues, the leachate, the crushed agricultural and forestry wastes, the feces and the sludge to obtain a waste mixture, adding a leavening agent into the waste mixture, uniformly stirring, and carrying out static fermentation; and finally, squeezing, dehydrating and crushing the waste mixture subjected to static fermentation, wherein the squeezed, dehydrated and crushed waste mixture can be used as alternative fuel, nutrient soil for landscaping or other aspects. The invention initiatively provides a process technical route of joint aerobic fermentation and ultrahigh-pressure mechanical squeezing dehydration of various organic solid wastes, and has the advantages of no need of an external heat source, low energy consumption, low cost, high dehydration efficiency, complete fermentation, no need of secondary treatment, short treatment period and good production environment.

Description

Technical Field

[0001] The invention belongs to the field of organic waste treatment, and in particular relates to a method for treating multi-source organic waste. Background Art

[0002] With the continuous improvement of my country's urbanization and industrialization levels, the amount of organic solid waste such as sludge is increasing year by year. Sludge and other organic solid wastes have a high natural water content. All treatment and disposal methods require the sludge to be dried, dehydrated and reduced in volume first. The existing sludge drying mainly includes various thermal drying, low-temperature heat pump drying, aerobic composting drying and solar drying technologies. Sludge incineration can achieve the greatest reduction and harmlessness, and is the mainstream technology for sludge treatment and disposal in large and medium-sized cities. In order to reduce the auxiliary energy consumption required for sludge incineration or to achieve autonomous combustion of sludge, sludge dehydration and drying is a very important pre-treatment link. The use of sludge after aerobic composting for landscaping is one of the best ways to realize the resource utilization of sludge.

[0003] Sludge drying is a process of net energy consumption, with high energy consumption and high costs. Traditional sludge thermal drying technology consumes a lot of heat energy, and has disadvantages such as large equipment investment, high energy consumption, high operating costs, explosion risks, and easy secondary pollution. Low-temperature heat pump drying requires a lot of electricity, and the current technical level also has problems such as large equipment footprint, serious corrosion damage to equipment caused by corrosive components contained in organic solid waste such as sludge, and low equipment reliability. Although traditional aerobic composting drying technology has the advantages of no external heat source and low operating cost, it also has the disadvantages of large footprint, difficult odor control, and long production cycle.

[0004] There are many existing methods for waste treatment. For example, the patent application with application number: 202410315874.X discloses an environmentally friendly agricultural waste treatment system and method, which belongs to the field of agricultural waste treatment technology. The treatment system includes a pretreatment module, an anaerobic fermentation module, a biogas utilization module, a biogas residue utilization module and a monitoring and control module. The pretreatment module is used to pretreat agricultural waste; the anaerobic fermentation module is used to perform anaerobic fermentation on pretreated organic waste; the biogas utilization module is used to collect, purify, store and comprehensively utilize the biogas produced by anaerobic fermentation; the biogas residue utilization module is used to further process and utilize the biogas produced by anaerobic fermentation; the monitoring and control module is used to collect and analyze the data of each module, and send control instructions to each module according to the preset intelligent control model and algorithm to realize process monitoring and optimization control. This application realizes the efficient treatment and resource utilization of agricultural waste, which not only reduces the pollution of agricultural waste to the environment, but also can transform waste into resources. However, it only targets agricultural waste and cannot treat multiple wastes at the same time. Summary of the invention

[0005] Based on the above technical background, the main purpose of the present invention is to provide a method for treating multi-source organic waste to overcome the shortcomings of the prior art.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0007] The present invention provides a method for treating multi-source organic waste, the method comprising the following steps:

[0008] Step 1, separating the sorted food waste to separate the solid residue and the leachate;

[0009] Step 2: crushing the agricultural and forestry waste, mixing the solid slag, leachate, crushed agricultural and forestry waste, excrement and sludge according to the carbon-nitrogen ratio and water content of the aerobic fermentation material, adding a fermentation agent, stirring and crushing together, stirring evenly to obtain a waste mixture, and performing static fermentation;

[0010] Step 3: squeeze and dehydrate the waste mixture after static fermentation, and then crush the mud cake obtained by squeezing and dehydration to obtain a treated waste mixture.

[0011] In step 2,

[0012] Preferably, the agricultural and forestry waste is crushed to less than 50 mm.

[0013] Preferably, the solid residue, leachate, crushed agricultural and forestry waste, manure and sludge are mixed, and the proportion of the waste mixture is adjusted so that the water content of the waste mixture is 55% to 65% and the carbon-nitrogen ratio is 25 to 35.

[0014] Preferably, the fermentation agent is selected from one or more of Bacillus, filamentous fungi, actinomycetes, yeasts and extracellular enzymes thereof.

[0015] More preferably, the fermentation agent is a mixture rich in Bacillus, filamentous fungi, actinomycetes and yeast.

[0016] Preferably, the amount of the fermentation agent added is 1 / 10,000 to 3 / 10,000 of the mass of the waste mixture.

[0017] Preferably, static fermentation is carried out in a fully sealed mechanized aerobic fermentation biological drying device;

[0018] The static fermentation conditions are as follows: oxygen content is 5% to 15%, static fermentation lasts for 1 to 3 days, and after the temperature reaches 65° C. to 80° C., heat preservation lasts for 1 to 2 days.

[0019] Preferably, the waste mixture after fermentation has a moisture content of 50% to 60%.

[0020] In step 3,

[0021] Preferably, the squeezing and dehydration is carried out in a heavy-loaded high-pressure press;

[0022] The waste mixture is squeezed and dehydrated until the moisture content is 30% to 50%.

[0023] The beneficial effects of the present invention are:

[0024] (1) Compared with thermal drying, the aerobic fermentation drying method of the present invention does not require an external heat source, has low energy consumption and low cost; the bacteria contained in the sludge after aerobic fermentation are killed, most of the odor is removed, and the internal water molecules are broken, which has great benefits for the production environment and production efficiency of subsequent mechanical pressing;

[0025] The present invention is the first to propose a process technology route of aerobic fermentation of various organic solid wastes + ultra-high pressure mechanical pressing and dehydration. Various organic solid wastes such as municipal sludge with a moisture content of 80% can be directly mixed with biomass auxiliary materials for aerobic fermentation treatment. There is no need to add a large amount of flocculants or lime to the sewage to improve the filter pressing efficiency and reduce the sludge moisture content to 60% or lower. The treatment method of the present invention has low cost, high dehydration efficiency and good production environment.

[0026] (2) Compared with the traditional trough-type and strip-type aerobic fermentation, the fully sealed mechanized aerobic fermentation biological drying equipment used in the present invention adopts a double-shaft gear mixer, which has a high degree of material mixing and homogenization, uniform porosity, and is conducive to the survival and reproduction of aerobic fermentation bacteria. Aerobic fermentation is complete, no anaerobic semi-reactants are produced, and the organic solid waste after aerobic fermentation has been sterilized and deodorized, and there is no secondary pollution problem in the subsequent production links; the water molecules inside the organic solid waste after aerobic fermentation have broken the wall, which is conducive to improving the efficiency of subsequent mechanical pressing and dehydration;

[0027] The drying equipment used in the present invention adopts implanted aeration, breaking through the limit of the traditional aerobic fermentation process that the material pile height can only reach 1.5 to 2 meters. The material layer pile height can reach more than 5 meters, thereby greatly reducing the occupied area; the equipment is a fully sealed external insulation structure, the odor collection and treatment are easy, the production is not affected by the ambient temperature, the heating speed is fast, the insulation time is long, and the fermentation cycle can be greatly shortened.

[0028] (3) Compared with conventional plate and frame filter presses that can only squeeze to a moisture content of 60% and require the addition of a large amount of flocculants, lime powder, etc. to improve the squeezing efficiency, the heavy-loaded high-pressure press used in the present invention has a high loading pressure, high squeezing efficiency, and does not require the addition of additional flocculants. The heavy-loaded high-pressure press used in the present invention can squeeze the product to a moisture content of less than 35%.

[0029] (4) The treatment method of the present invention organically combines the advantages of low cost and low consumption of aerobic fermentation with the advantages of fast and efficient dehydration of heavy-load high-pressure pressing. After 1 to 3 days, various organic solid wastes such as sludge with high water content, kitchen waste, livestock and poultry feces can be treated into nutrient soil or alternative fuel with low water content, sterilization and deodorization, thus achieving the goal of harmless and resourceful treatment of solid waste. The cost of aerobic fermentation of one ton of sludge is less than 150 yuan, and the cost of pressing is less than 40 yuan. The low calorific value of the pressed product can reach 1500 to 2000 kcal / kg. In addition, the equipment occupies a small area, has a short construction period, and a fast investment recovery. The treatment method has good application prospects in the field of organic solid waste treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram showing a method for treating multi-source organic waste according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below, and the characteristics and advantages of the present invention will become clearer and more distinct with the description.

[0032] The present invention provides a method for treating multi-source organic waste, the method comprising the following steps:

[0033] Step 1: Add the sorted food waste into a three-phase separator to separate the solid phase residue and the leachate;

[0034] Step 2: crushing the agricultural and forestry waste, mixing the solid slag, leachate, crushed agricultural and forestry waste, excrement and sludge according to the carbon-nitrogen ratio and water content of the aerobic fermentation material, adding a fermentation agent, stirring and crushing together, stirring evenly to obtain a waste mixture, and performing static fermentation;

[0035] Step 3: squeeze and dehydrate the waste mixture after static fermentation, and then crush the mud cake obtained by squeezing and dehydration to obtain a treated waste mixture, which can be used as an alternative fuel or nutrient soil for landscaping.

[0036] The above steps are described in detail below. Figure 1 shown.

[0037] In step 1, the kitchen waste is first sorted for large substances and then added to a three-phase separator. The separated crude oil is sold separately, and the separated solid residue and leachate are combined with sludge, livestock and poultry manure, etc. for aerobic fermentation.

[0038] In step 2, agricultural and forestry waste, such as straw, peanut shells, corn cobs, garden garbage, etc., are crushed to less than 50 mm, preferably, crushed to less than 25 mm, and unloaded into the (agricultural and forestry waste) live-bottom auxiliary material silo as auxiliary materials. Multiple feeders at the bottom of the silo evenly transport them to the discharge screw conveyor.

[0039] The solid residue, leachate, crushed agricultural and forestry wastes, manure and sludge are mixed, and the proportion of the mixture is adjusted so that the moisture content of the mixture is 55% to 65% and the carbon-nitrogen ratio is 25 to 35.

[0040] Preferably, the proportion of the mixture is adjusted so that the water content of the mixture is 58% to 62% and the carbon-nitrogen ratio is 28 to 32.

[0041] The fermentation agent is selected from one or more of Bacillus, filamentous fungi, actinomycetes, yeast and extracellular enzymes thereof.

[0042] Preferably, the fermentation agent is a mixture rich in Bacillus, filamentous fungi, actinomycetes and yeast.

[0043] The amount of the fermentation agent added is 1 / 10,000 to 3 / 10,000 of the mass of the waste mixture. Preferably, the amount of the fermentation agent added is 1 / 10,000 of the mass of the waste mixture.

[0044] The evenly mixed waste mixture and fermentation agent are transported to a fully sealed mechanized aerobic fermentation biological drying equipment for static fermentation. During the fermentation, the temperature and oxygen content of the pile are continuously detected. The automatic control system starts and stops the oxygen supply fan to supplement oxygen for the pile according to the detected temperature, oxygen content and preset start and stop limits, ensuring that the oxygen content of the pile is 5% to 15% to meet the needs of microbial survival and reproduction. After 1 to 2 days of fermentation, the pile temperature reaches a high temperature of 65℃ to 80℃ and is maintained for a certain period of time, thereby killing various pathogens contained in the sludge, decomposing some organic matter, removing foul odors, and breaking the internal water molecules.

[0045] The static fermentation conditions are: oxygen content of 5% to 15%, static fermentation for 1 to 3 days, after the temperature reaches 65°C to 80°C, heat preservation for 1 to 2 days, and the water content of the waste mixture after fermentation is 50% to 60%.

[0046] Preferably, the static fermentation conditions are: oxygen content of 7% to 12%, static fermentation for 1 to 2 days, after the temperature reaches 70°C to 75°C, insulation for 1 day, and the water content of the waste mixture after fermentation is 50% to 60%.

[0047] In step 3, after fermentation, the output material is crushed by a high-speed rotating crusher, and the waste material is fluffy and odorless, mixed evenly, and is very convenient to transport and store.

[0048] It is sent to a heavy-load high-pressure press through a conveying system for further dehydration to a moisture content of 30% to 50%, preferably 35% to 45%. The dehydrated water cake can be crushed and used as nutrient soil for landscaping. The part that cannot be absorbed by the landscaping market can be sold in bulk form or reprocessed into pellets as a biomass alternative fuel to independent incinerators, thermal power plants, cement plants, waste incineration plants, etc.

[0049] Example

[0050] The present invention is further described below by means of specific examples. These embodiments are only intended to illustrate the present invention but are not intended to limit the scope of the present invention.

[0051] Example 1

[0052] The kitchen waste is first sorted for large substances and then added to a three-phase separator. The separated crude oil is sold separately, and the separated solid residue and leachate are combined with sludge, livestock and poultry manure, etc. for aerobic fermentation.

[0053] Agricultural and forestry waste, such as straw, peanut shells, corn cobs, garden garbage, etc., are crushed to less than 50mm and fed into the (agricultural and forestry waste) live-bottom auxiliary material bin as auxiliary materials. Multiple feeders at the bottom of the bin evenly transport them to the discharge screw conveyor. The solid phase residue, leachate, crushed agricultural and forestry waste, feces and sludge are mixed, and the proportion of the mixture is adjusted to make the moisture content of the mixture 58% to 62%, the carbon-nitrogen ratio 28 to 32, and the fermentation agent is added in a prescribed proportion. The fermentation agent is a mixture rich in Bacillus, filamentous fungi, actinomycetes, and yeast. The amount of the fermentation agent added is one ten-thousandth of the mass of the waste mixture. The fermentation agent is added through a quantitative feeding screw of a variable frequency speed regulating dosing device, and the mixture is fed into a double-shaft mixer for mixing and crushing to obtain a waste mixture. The waste is transported to a fully sealed mechanized aerobic fermentation biological drying device for static fermentation. During the fermentation, the temperature and oxygen content of the pile are continuously detected. The automatic control system starts and stops the oxygen supply fan to supplement oxygen for the pile according to the detected temperature, oxygen content and the preset start and stop limits. The static fermentation conditions are: oxygen content of 7% to 12%, static fermentation for 1 to 2 days, after the temperature reaches 70°C to 75°C, it is kept warm for 1 day, and the moisture content of the waste mixture after fermentation is 50% to 60%.

[0054] After fermentation, the waste is crushed in a high-speed rotating crusher and then sent to a heavy-duty high-pressure press by a conveying system for further squeezing and dehydration until the moisture content of the waste mixture reaches 35% to 45%. The dehydrated mud cake can be crushed and used as nutrient soil for landscaping. The part that cannot be absorbed by the landscaping market can be sold in bulk or processed into pellets as a biomass alternative fuel to independent incinerators, thermal power plants, cement plants, waste incineration plants, etc. Figure 1 shown.

[0055] Example 2

[0056] The kitchen waste is first sorted for large substances and then added to a three-phase separator. The separated crude oil is sold separately, and the separated solid residue and leachate are combined with sludge, livestock and poultry manure, etc. for aerobic fermentation.

[0057] Agricultural and forestry waste, such as straw, peanut shells, corn cobs, garden waste, etc., are crushed to less than 50mm and fed into the (agricultural and forestry waste) live-bottom auxiliary material bin as auxiliary materials. Multiple feeders at the bottom of the bin evenly transport them to the discharge screw conveyor. The solid phase residue, leachate, crushed agricultural and forestry waste, feces and sludge are mixed, and the proportion of the mixture is adjusted to make the moisture content of the mixture 55% to 60% and the carbon-nitrogen ratio 25 to 30. The fermentation agent is added in a prescribed proportion. The fermentation agent is a mixture rich in bacillus, filamentous fungi, actinomycetes and yeast. The amount of the fermentation agent added is 0.02% of the mass of the waste mixture. The fermentation agent is added by a quantitative feeding screw of a variable frequency speed regulating dosing device and transported to a fully sealed mechanized aerobic fermentation biological drying equipment for static fermentation. During the fermentation, the temperature and oxygen content of the pile are continuously detected. The automatic control system starts and stops the oxygen supply fan to supplement oxygen for the pile according to the detected temperature, oxygen content values ​​and the preset start and stop limits. The static fermentation conditions are: oxygen content of 5% to 10%, static fermentation for 1 to 2 days, after the temperature reaches 65°C to 70°C, heat preservation for 2 days, and the water content of the waste mixture after fermentation is 50% to 60%.

[0058] After fermentation, the material is crushed in a high-speed rotating crusher and then sent to a heavy-load high-pressure press by a conveying system for further squeezing and dehydration until the moisture content of the waste mixture reaches 30% to 40%. The mud cake after squeezing and dehydration can be crushed and used as nutrient soil for landscaping. The part that cannot be consumed by the landscaping market can be sold in bulk form or reprocessed into granules as biomass alternative fuel to independent incinerators, thermal power plants, cement plants, waste incineration plants, etc.

[0059] Example 3

[0060] The kitchen waste is first sorted for large substances and then added to a three-phase separator. The separated crude oil is sold separately, and the separated solid residue and leachate are combined with sludge, livestock and poultry manure, etc. for aerobic fermentation.

[0061] Agricultural and forestry waste, such as straw, peanut shells, corn cobs, garden waste, etc., are crushed to less than 25mm and passed into the (agricultural and forestry waste) live-bottom auxiliary material bin as auxiliary materials. Multiple feeders at the bottom of the bin evenly transport them to the discharge screw conveyor. The solid phase residue, leachate, crushed agricultural and forestry waste, feces and sludge are mixed, and the proportion of the mixture is adjusted to make the moisture content of the mixture 60% to 65% and the carbon-nitrogen ratio 30 to 35. The fermentation agent is added in a prescribed proportion. The fermentation agent is a mixture rich in bacillus, filamentous fungi, actinomycetes and yeast. The amount of the fermentation agent added is 0.03% of the mass of the waste mixture. The fermentation agent is added by a quantitative feeding screw of a variable frequency speed regulating dosing device and transported to a fully sealed mechanized aerobic fermentation biological drying equipment for static fermentation. During the fermentation, the temperature and oxygen content of the pile are continuously detected. The automatic control system starts and stops the oxygen supply fan to supplement oxygen to the pile according to the detected temperature, oxygen content values ​​and the preset start and stop limits. The static fermentation conditions are: oxygen content of 10% to 15%, static fermentation for 1 to 3 days, after the temperature reaches 70°C to 80°C, heat preservation for 1 day, and the water content of the waste mixture after fermentation is 50% to 60%.

[0062] After fermentation, the material is crushed in a high-speed rotating crusher and then sent to a heavy-load high-pressure press by a conveying system for further squeezing and dehydration until the moisture content of the waste mixture reaches 40% to 50%. The dehydrated mud cake can be crushed and used as nutrient soil for landscaping. The part that cannot be consumed by the landscaping market can be sold in bulk form or reprocessed into granules as a biomass alternative fuel to independent incinerators, thermal power plants, cement plants, waste incineration plants, etc.

[0063] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for treating multi-source organic waste, characterized in that: The processing method comprises the following steps: Step 1, separating the sorted food waste to separate the solid residue and the leachate; Step 2: crushing the agricultural and forestry waste, mixing the solid slag, leachate, crushed agricultural and forestry waste, excrement and sludge according to the carbon-nitrogen ratio and water content of the aerobic fermentation material, adding a fermentation agent, stirring and crushing together, stirring evenly to obtain a waste mixture, and performing static fermentation; Step 3: squeeze and dehydrate the waste mixture after static fermentation, and then crush the mud cake obtained by squeezing and dehydration to obtain a treated waste mixture.

2. The processing method according to claim 1, characterized in that: In step 2, Crush agricultural and forestry waste to less than 50mm.

3. The processing method according to claim 1, characterized in that: In step 2, The solid residue, leachate, crushed agricultural and forestry waste, manure and sludge are mixed, and the proportion of the waste mixture is adjusted so that the water content of the waste mixture is 55% to 65% and the carbon-nitrogen ratio is 25 to 35.

4. The processing method according to claim 1, characterized in that: In step 2, The fermentation agent is selected from one or more of Bacillus, filamentous fungi, actinomycetes, yeast and extracellular enzymes thereof.

5. The processing method according to claim 4, characterized in that: In step 2, The fermentation agent is a mixture rich in bacillus, filamentous fungi, actinomycetes and yeast.

6. The processing method according to claim 1, characterized in that: In step 2, The addition amount of the fermentation agent is 1 / 10,000 to 3 / 10,000 of the mass of the waste mixture.

7. The processing method according to claim 1, characterized in that: In step 2, Static fermentation is carried out in a fully sealed mechanized aerobic fermentation bio-drying equipment; The static fermentation conditions are: oxygen content of 5% to 15%, static fermentation for 1 to 3 days, and after the temperature reaches 65° C. to 80° C., heat preservation for 1 to 2 days.

8. The processing method according to claim 1, characterized in that: In step 2, The water content of the waste mixture after fermentation is 50% to 60%.

9. The processing method according to claim 1, characterized in that: In step 3, Pressing and dehydration are carried out in a heavy-loaded high-pressure press; The waste mixture is squeezed and dehydrated until the moisture content is 30% to 50%.

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