阅读说明：本技术 一种生物炭-麦秸秆改良城镇污泥微曝气混合堆肥方法 (Biochar-wheat straw modified town sludge micro-aeration mixed composting method ) 是由 成庆利 张龙龙 于 2020-04-30 设计创作，主要内容包括：本发明公开一种生物炭-麦秸秆改良城镇污泥微曝气混合堆肥方法,包括以下步骤：a.将城镇污水处理厂剩余污泥、麦秸秆粉和生物炭按湿基质量比1：(0.30-0.40)：(0.020-0.030)混合,得混合物料,该物料含水率为65-70%,碳氮比为21-25；b.将混合物料进行发酵,腐熟,得生物炭-麦秸秆混合堆肥。本发明通过添加生物炭和麦秸秆粉以及采用微曝气系统的城镇污泥混合堆肥,减少堆肥过程氮素损失,增加了堆肥产品肥效,降低堆肥过程能耗,并实现城镇污泥和废弃麦秸秆的资源化利用。(The invention discloses a biochar-wheat straw modified town sludge micro-aeration mixed composting method which comprises the following steps: a. mixing the excess sludge of the urban sewage treatment plant, the wheat straw powder and the biochar according to a wet-based mass ratio of 1: (0.30-0.40): (0.020-0.030) to obtain a mixed material, wherein the water content of the material is 65-70%, and the carbon-nitrogen ratio is 21-25; b. and fermenting and decomposing the mixed materials to obtain the biochar-wheat straw mixed compost. According to the invention, by adding the biochar and the wheat straw powder and adopting the town sludge mixed composting of the micro-aeration system, the nitrogen loss in the composting process is reduced, the fertilizer efficiency of the composting product is increased, the energy consumption in the composting process is reduced, and the resource utilization of the town sludge and the waste wheat straw is realized.)

1. A biochar-wheat straw modified town sludge micro-aeration mixed composting method is characterized by comprising the following steps: the method comprises the following steps:

mixing the excess sludge of the urban sewage treatment plant, the wheat straw powder and the biochar according to a wet-based mass ratio of 1: (0.30-0.40): (0.020-0.030) to obtain a mixed material, wherein the water content of the material is 65-70%, and the carbon-nitrogen ratio is 21-25;

and fermenting and decomposing the mixed materials to obtain the biochar-wheat straw mixed compost.

2. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: in the step a, the residual sludge, the wheat straw powder and the biochar are mixed according to a wet-based mass ratio of 1: 0.35: 0.025 and mixing.

3. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: b, putting the mixed material in a fermentation device, performing aerobic fermentation on the mixed material in a mode of combining a micro-aeration system and manual forced turning, wherein the ventilation rate is 0.1-0.2L/min/kg of wet base, and turning the mixed material at intervals of several days; fermenting for 20-25 days, and decomposing to obtain the biochar-wheat straw mixed compost.

4. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 3, which is characterized in that: the turning at intervals of several days refers to turning on 2 nd, 4 th, 6 th, 8 th, 10 th and 14 th days respectively.

5. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: the water content of the biochar is 2% -5%.

6. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: the particle size of the biochar is 80-105 meshes.

7. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: the water content of the wheat straw powder is 0.65-0.80%.

8. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: the grain size of the wheat straw powder is 0.5-2 mm.

9. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 1, which is characterized in that: the water content of the excess sludge of the urban sewage treatment plant is 75-85%, and the content of organic matters is 500-700 g/kg of dry basis.

10. The biochar-wheat straw modified town sludge micro-aeration mixed composting method as claimed in claim 3, which is characterized in that: the aeration system adopts a micro-aeration system, and the aeration rate is preferably 0.18L/min/kg wet basis.

Technical Field

The invention relates to the technical field of solid waste recycling, in particular to an aerobic fermentation process for town sludge composting, which improves the effect of the town sludge composting by utilizing biochar-wheat straw and a micro-aeration system.

Background

With the gradual increase of daily sewage treatment amount of urban sewage treatment plants in China, the sludge yield is increased day by day, however, about 60 percent of sludge in China is only simply buried at present, and about 23 percent of sludge is not treated at all and is randomly piled up, so that the serious waste of sludge resources is caused. The town sludge contains a large amount of organic matters, energy, nitrogen, phosphorus, potassium and other nutrient substances, and the stabilization and the recycling of the sludge can be realized after the compost fermentation, so that the town sludge is a relatively proper way for the sludge. However, the fermentation period of the aerobic composting of the sludge is long, the nitrogen loss in the composting process is serious, and the composting effect is not good.

The biochar has a developed pore structure and a large specific surface area, can provide a strong attachment space for microorganisms, enhances the activity of the microorganisms, improves the nitrification process, and can be used as a mixture to form biochar soil without being screened and recovered from compost products, thereby simplifying the sludge composting process. The wheat straw powder has rich organic carbon content, can improve the condition of low carbon-nitrogen ratio of sludge, can improve the air permeability of the mixed material by adding the wheat straw powder, and reduces the generation of hydrogen sulfide in a reactor anaerobic environment. Therefore, the town sludge mixed composting condition can be improved by adding the biochar and the wheat straw powder, the odor emission in the sewage composting process is reduced, and the fertilizer efficiency of sludge compost products is improved.

The traditional sludge composting aeration system has the problems of large loss of a pipeline system, high energy consumption, easy blockage of aeration holes and the like. The aeration disc with the nano-aperture and the aeration device with the aeration bin and the fermentation bin separated are adopted, and the pressure difference between the aeration bin and the fermentation bin is utilized to enable gas to be better transferred and utilized in the stockpile with good air permeability, so that the loss of a pipeline system is reduced, and the energy consumption is reduced.

Disclosure of Invention

The invention aims to provide a method for improving town sludge micro-aeration mixed composting by using biochar-wheat straw, which improves town sludge composting effect by using a biochar and micro-aeration system, can reduce nitrogen loss in the composting process, improves the fertilizer efficiency of composting products, and shortens the fermentation period of sludge composting.

The purpose of the invention is realized by the following technical scheme:

a biochar-wheat straw modified town sludge micro-aeration mixed composting method comprises the following steps:

a. mixing the excess sludge of the urban sewage treatment plant, the wheat straw powder and the biochar according to a wet-based mass ratio of 1: (0.30-0.40): (0.020-0.030) to obtain a mixed material, wherein the water content of the material is 65-70%, and the carbon-nitrogen ratio is 21-25;

b. and fermenting and decomposing the mixed materials to obtain the biochar-wheat straw mixed compost.

According to the method for improving town sludge micro-aeration mixed composting by using biochar-wheat straw, in the step a, the residual sludge, the wheat straw powder and the biochar are mixed according to a wet-based mass ratio of 1: 0.35: 0.025 and mixing.

The biochar-wheat straw modified town sludge micro-aeration mixed composting method comprises the step b of subjecting a mixed material to aerobic fermentation in a fermentation device in a mode of combining a micro-aeration system and manual forced turning, wherein the ventilation rate is 0.1-0.2L/min/kg of wet base, and turning is carried out at intervals of several days; fermenting for 20-25 days, and decomposing to obtain the biochar-wheat straw mixed compost.

According to the method for improving the town sludge micro-aeration mixed composting by the biochar-wheat straw, the turning at intervals of several days is carried out on days 2, 4, 6, 8, 10 and 14 respectively.

According to the method for improving town sludge micro-aeration mixed composting by using biochar-wheat straw, the water content of the biochar is 2% -5%.

According to the method for improving town sludge micro-aeration mixed composting by using biochar-wheat straw, the granularity of the biochar is 80-105 meshes, and is preferably 95 meshes.

According to the method for improving town sludge micro-aeration mixed composting by using biochar-wheat straw, the moisture content of the wheat straw powder is 0.65-0.80, and preferably 0.72%.

According to the method for improving the town sludge micro-aeration mixed composting by the biochar-wheat straw, the particle size of the wheat straw powder is 0.5-2mm, and the optimal particle size is 1 mm.

According to the method for improving the town sludge micro-aeration mixed composting by using the biochar-wheat straw, the water content of the residual sludge of the town sewage treatment plant is 75-85%, and the organic matter content is 500-700 g/kg dry basis.

According to the biochar-wheat straw modified town sludge micro-aeration mixed composting method, the micro-aeration system is adopted in the aeration system, and the aeration rate is preferably 0.18L/min/kg of wet basis.

By adopting the technical scheme, the invention has the beneficial effects that:

according to the invention, the biochar is added to enhance microbial attachment, improve microbial community activity, enhance nitration process, promote decomposition and shorten sludge composting period. The characteristic of low carbon-nitrogen ratio content of the sludge is improved by adding the wheat straw powder, the air permeability of the sludge pile is improved, a sufficient carbon source is provided for the growth of microorganisms, and the gas circulation effect is better.

According to the invention, by adding the biochar and the wheat straw powder and adopting the town sludge mixed composting of the micro-aeration system, the nitrogen loss in the composting process is reduced, the fertilizer efficiency of the composting product is increased, the energy consumption in the composting process is reduced, and the resource utilization of the town sludge and the waste wheat straw is realized.

Detailed Description