阅读说明：本技术 一种农畜废弃物、生活垃圾协同利用及重金属控制工艺 (Process for synergistic utilization of agricultural and livestock wastes and household garbage and heavy metal control ) 是由 林常枫 杨开宇 李刚 刘强强 敖琎 章力 于 2019-10-22 设计创作，主要内容包括：本发明公开了一种农畜废弃物、生活垃圾协同利用及重金属控制工艺,包括如下三部分：厌氧发酵工段、堆肥工段和锅炉焚烧工段。本发明可获取厌氧发酵工艺的多种副产品(沼气、水溶肥、固态有机肥)、可利用堆肥工艺提升有机肥肥效和实现低能耗降低含水率、可采用焚烧工艺对污染物实现减量化以及富集重金属至飞灰中实现重金属的低成本安全处理；解决了厌氧发酵和堆肥产物重金属无法有效控制的技术难题,同时可弥补生物质或生活垃圾单一原料不足时焚烧经济性差以及畜禽粪便干化焚烧耗能高的缺点,真正地实现了废物资源化、无害化、减量化和经济化处理。(The invention discloses a process for cooperative utilization of agricultural and livestock wastes and household garbage and heavy metal control, which comprises the following three parts: anaerobic fermentation section, composting section and boiler incineration section. The invention can obtain various byproducts (methane, water-soluble fertilizer and solid organic fertilizer) of the anaerobic fermentation process, can utilize the composting process to improve the fertilizer efficiency of the organic fertilizer and realize low energy consumption and water content reduction, can adopt the incineration process to reduce pollutants and enrich heavy metals into fly ash to realize low-cost safe treatment of the heavy metals; the method solves the technical problems of anaerobic fermentation and ineffective control of heavy metals in compost products, can make up for the defects of poor incineration economy when single raw materials of biomass or household garbage are insufficient and high energy consumption of drying and incineration of livestock and poultry manure, and truly realizes the recycling, harmless, quantitative reduction and economical treatment of wastes.)

1. A process for the synergistic utilization of agricultural and livestock wastes and household garbage and the control of heavy metals is characterized by comprising the following three parts: anaerobic fermentation section, composting section and boiler incineration section;

the anaerobic fermentation section comprises the following steps: crushing biomass, mixing the crushed biomass with livestock and poultry manure, adding an inoculum, uniformly mixing, and performing medium-temperature wet anaerobic fermentation to generate methane and residues;

the composting section comprises the following steps: uniformly mixing the biogas residues and the biomass, conveying the mixture to a tank-type fermentation device for high-temperature composting treatment, after the composting is finished, carrying out heavy metal detection on the biogas residues, if the heavy metals reach the standard, conveying the biogas residues to an organic fertilizer production workshop to prepare organic fertilizers for sale, and if the heavy metals of the biogas residues do not reach the standard, conveying the biogas residues to a boiler incineration workshop section;

the boiler incineration section comprises the following steps: directly feeding the biogas residues, the biomass and the household garbage into a boiler for incineration, simultaneously introducing the compost gas into a boiler for auxiliary fuel combustion, and heating boiler water to generate steam; heavy metals after incineration accumulate in the fly ash, chelating and solidifying.

2. The process for the synergistic utilization of agricultural and livestock wastes and household garbage and the control of heavy metals according to claim 1, wherein the anaerobic fermentation section comprises the following specific steps:

crushing the biomass to 1.5-2.5 mm, mixing the biomass and the livestock and poultry manure according to a proportion until the C/N ratio of fermentation raw materials is (25-30) to 1, adding 20% of inoculum, adding water according to the situation to adjust the water content to 88-92%, fully mixing the mixture evenly, feeding the mixture into a CSTR fermentation tank for middle-temperature wet anaerobic fermentation for 10-20 days, and fermenting to generate biogas and residues.

3. The process for synergistic utilization of agricultural and livestock wastes and household garbage and heavy metal control as claimed in claim 2, wherein the temperature of the medium temperature wet anaerobic fermentation is 30-35 ℃ and the pH is 6.5-8.0.

4. The process of claim 3, wherein the residues enter a filter-pressing solid-liquid separation device, the biogas slurry obtained through separation is subjected to precipitation/filtration, ozone disinfection, pH adjustment and nutrient component doping to prepare water-soluble fertilizers for sale, the biogas residues with the water content of 55-65% generated through separation are subjected to heavy metal detection, if the heavy metals reach the standard, the biogas residues are transported to an organic fertilizer production workshop to prepare organic fertilizers for sale, and if the heavy metals do not reach the standard, the biogas residues are transported to a composting workshop.

5. The process of claim 2, wherein the biogas is used for purification to produce CNG or for power generation and sale.

6. The process for the synergistic utilization of agricultural and livestock wastes and household garbage and the control of heavy metals according to claim 4 or 5, which is characterized in that the composting section comprises the following specific steps:

uniformly mixing the biogas residues and the biomass in proportion, adjusting the C/N ratio to be (25-30) to 1, conveying the biogas residues and the biomass into a tank type fermentation device for high-temperature composting treatment, controlling the temperature to be 45-60 ℃, keeping the temperature of the material to be above 55 ℃ for at least 5 days, controlling the water content of the initial material to be 50-60% and the pH to be 6.0-8.0;

and after composting, reducing the water content of the biogas residues to 18-22%, detecting heavy metals in the biogas residues, if the heavy metals reach the standard, transporting the biogas residues to an organic fertilizer production workshop to prepare organic fertilizers for sale, and if the heavy metals in the biogas residues do not reach the standard, transporting the biogas residues to a boiler incineration section.

7. The process for cooperative utilization of agricultural and livestock wastes and household garbage and control of heavy metals as claimed in claim 6, wherein the bottom of the tank type fermentation equipment is ventilated and supplied with oxygen, and the material is turned once every 1-3 days by using a turner.

8. The process of claim 7, wherein forced ventilation is used to prevent odor pollution during composting, and compost gas is fed to boiler as combustion air.

9. The process for the synergistic utilization of agricultural and livestock wastes and household garbage and the control of heavy metals according to claim 8, wherein the specific steps of the boiler incineration section are as follows:

directly feeding the biogas residues with the water content of 18-22% into a boiler together with biomass and household garbage for incineration without extra energy consumption, and simultaneously introducing compost gas into a boiler for auxiliary fuel combustion to heat boiler water to generate steam; heavy metals after incineration accumulate in fly ash and are chelated and solidified by cement.

10. The process of claim 9, wherein the steam can be used for heating, steam supply or power generation.

Technical Field

The invention relates to the technical field of ecological environment protection, in particular to a process for the cooperative utilization of agricultural and livestock wastes and household garbage and the control of heavy metals.

Background

Currently, the problem of pollution of animal husbandry, agricultural waste and domestic waste has become a focus of global attention. In the field of animal husbandry, according to statistics of 2017, livestock and poultry manure produced in China is as high as 38 hundred million tons, but only about half of the livestock and poultry manure is comprehensively utilized, which means that nearly 20 hundred million tons of livestock and poultry manure cannot be properly treated, and thus huge negative effects are caused on various aspects of ecological environment, human health, regional appearance and the like. In agriculture, 2.15 million tons of 8.2 million tons of crop straws are incinerated and discarded every year in China. Not only wastes energy and reduces the organic matter content of soil, but also leads to soil hardening and water storage capacity reduction, and also seriously pollutes atmosphere and water environment. In the aspect of domestic garbage pollution, the accumulated quantity of domestic garbage in cities in China exceeds 65 hundred million tons, the domestic garbage occupies about 35 hundred million square meters of land, large and medium cities of 2/3 are surrounded by garbage in 660 cities in the country, and cities of 1/4 are forced to extend a way for solving the garbage crisis to the villages, so that the garbage secondary pollution is caused, and the ecological environment of urban and rural combined areas is rapidly deteriorated.

In order to solve the problem of pollution of livestock husbandry, agricultural wastes and household garbage, the state provides notice of the development and development planning of the energy agency of the State development and reform Commission on the printing and issuing, and points out that the liquid fuel, the gas fuel and the solid forming fuel of the biomass are actively developed to promote the biogas power generation and the biomass gasification power generation. In 2017, the country sets the three provinces of Jiangxi, Fujian and Guizhou as the first ecological civilization test area in the country, and marks that the construction of the ecological civilization test area in China enters the comprehensive development and accelerated promotion stage. In this context, it is very necessary to perform animal husbandry, agriculture and domestic waste treatment.

For agricultural wastes and household garbage, direct-fired power generation is the most mature treatment technology at present, but biomass and garbage power generation has feasibility in regions with better resources, and the power generation scale is small and the economical efficiency is poor when the amount of single resource raw materials is small. For livestock and poultry manure with higher water content, more external energy needs to be consumed in a drying and burning mode, and the economic benefit of the project is influenced. Therefore, the method of treating agricultural, animal husbandry and domestic garbage by direct combustion incineration has many limitations.

The current common use of livestock and poultry manure is anaerobic fermentation and composting. Although the excrement can be converted into biogas manure or biogas to realize resource utilization, the heavy metal content in the livestock excrement generally exceeds the standard due to the fact that a large amount of heavy metal is added into the feed. On one hand, the quality of the biogas manure is influenced, the project income is reduced, on the other hand, soil pollution is caused by applying the biogas manure with heavy metals exceeding the standard, and the heavy metals finally enter human bodies through agricultural products to harm the health of the human bodies. Passivation is a wide heavy metal treatment mode applied at present, but only converts the form of heavy metal into a stable insoluble compound, and does not realize the separation and removal of the heavy metal. After returning the biogas manure to the field, the heavy metals will face the risk of secondary release. So far, reports of really realizing effective control and safe removal of the heavy metal in the biogas manure in the industrial application field are not seen. Therefore, it is important to provide a new scheme for effectively controlling and removing heavy metals in livestock and poultry manure, which meets the environmental protection requirements and is technically and economically feasible.

In conclusion, in the area suffering from the pollution of various wastes such as biomass, livestock and poultry manure, household garbage and the like, a novel technology for realizing the cooperative utilization of multiple pollutants and the effective control and standard emission of heavy metals is developed, so that the problem of regional ecological environment pollution can be thoroughly solved, the requirements of national ecological civilization construction and sustainable development are met, and the method has very strong practical requirements.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a process for the cooperative utilization of agricultural and livestock wastes and domestic garbage and the control of heavy metals, aims to comprehensively solve the problem of the trouble of multiple pollutants of agricultural, animal husbandry and urban domestic garbage in the area through the cooperative resource utilization of biomass, animal excrements and domestic garbage, solves the problems of poor incineration economy and high energy consumption of animal excrements in drying and incineration when single raw materials of biomass or domestic garbage are insufficient, and simultaneously, also aims to realize the effective control of heavy metals in byproducts, ensure the standard emission and solve the problem of heavy metal pollution of animal excrements.

In order to achieve the purpose, the invention adopts the following technical scheme:

a process for the synergistic utilization of agricultural and livestock wastes and domestic garbage and the control of heavy metals comprises the following three parts: anaerobic fermentation section, composting section and boiler incineration section;

the anaerobic fermentation section comprises the following steps: crushing biomass, mixing the crushed biomass with livestock and poultry manure, adding an inoculum, uniformly mixing, and performing medium-temperature wet anaerobic fermentation to generate methane and residues;

the composting section comprises the following steps: uniformly mixing the biogas residues and the biomass, conveying the mixture to a tank-type fermentation device for high-temperature composting treatment, after the composting is finished, carrying out heavy metal detection on the biogas residues, if the heavy metals reach the standard, conveying the biogas residues to an organic fertilizer production workshop to prepare organic fertilizers for sale, and if the heavy metals of the biogas residues do not reach the standard, conveying the biogas residues to a boiler incineration workshop section;

the boiler incineration section comprises the following steps: directly feeding the biogas residues, the biomass and the household garbage into a boiler for incineration, simultaneously introducing the compost gas into a boiler for auxiliary fuel combustion, and heating boiler water to generate steam; heavy metals after incineration accumulate in the fly ash, chelating and solidifying.

The technical scheme is further set, and the anaerobic fermentation section comprises the following specific steps:

crushing the biomass to 1.5-2.5 mm, mixing the biomass and the livestock and poultry manure according to a proportion until the C/N ratio of fermentation raw materials is (25-30) to 1, adding 20% of inoculum, adding water according to the situation to adjust the water content to 88-92%, fully mixing the mixture evenly, feeding the mixture into a CSTR fermentation tank for middle-temperature wet anaerobic fermentation for 10-20 days, and fermenting to generate biogas and residues.

Preferably, the temperature of the medium-temperature wet anaerobic fermentation is 30-35 ℃, and the pH value is 6.5-8.0.

According to the technical scheme, the residues enter filter-pressing solid-liquid separation equipment, biogas slurry obtained through separation is subjected to precipitation/filtration, ozone disinfection, pH adjustment and nutrient component doping to prepare water-soluble fertilizer for sale, heavy metal detection is carried out on biogas residues with the water content of 55-65% generated through separation, if the heavy metal reaches the standard, the biogas residues are transported to an organic fertilizer production workshop to prepare organic fertilizer for sale, and if the heavy metal of the biogas residues does not reach the standard, the biogas residues are transported to a composting workshop section.

Preferably, the biogas is used for purifying to prepare CNG or for electricity generation and sale.

The technical scheme is further set, and the composting section comprises the following specific steps:

uniformly mixing the biogas residues and the biomass in proportion, adjusting the C/N ratio to be (25-30) to 1, conveying the biogas residues and the biomass into a tank type fermentation device for high-temperature composting treatment, controlling the temperature to be 45-60 ℃, keeping the temperature of the material to be above 55 ℃ for at least 5 days, controlling the water content of the initial material to be 50-60% and the pH to be 6.0-8.0;

and after composting, reducing the water content of the biogas residues to 18-22%, detecting heavy metals in the biogas residues, if the heavy metals reach the standard, transporting the biogas residues to an organic fertilizer production workshop to prepare organic fertilizers for sale, and if the heavy metals in the biogas residues do not reach the standard, transporting the biogas residues to a boiler incineration section.

The technical scheme is further set, the bottom of the groove type fermentation equipment is ventilated and supplied with oxygen, and the material is turned once by using the turner every 1-3 days.

The technical scheme is further set, in order to prevent odor pollution generated in the composting process, a forced ventilation mode of a closed workshop is adopted, and composting gas is sent to a boiler to be used as combustion-supporting air.

The technical scheme is further set, and the specific steps of the boiler incineration section are as follows:

directly feeding the biogas residues with the water content of 18-22% into a boiler together with biomass and household garbage for incineration without extra energy consumption, and simultaneously introducing compost gas into a boiler for auxiliary fuel combustion to heat boiler water to generate steam; heavy metals after incineration are accumulated in fly ash, great reduction treatment is realized, and the heavy metals can be prevented from being released into soil for the second time by adopting low-cost cement chelation and solidification.

Preferably, the steam can be used for heating, steam supply or power generation.

Compared with the prior art, the invention has the following advantages and positive effects:

(1) the method has the advantages of three processes of anaerobic fermentation, composting and incineration, can obtain various byproducts (methane, water-soluble fertilizer and solid organic fertilizer) of the anaerobic fermentation process, can improve the fertilizer efficiency of the organic fertilizer and realize low energy consumption and water content reduction by using the composting process, and can realize the reduction of pollutants and the low-cost safe treatment of heavy metals by enriching the heavy metals into fly ash by using the incineration process; meanwhile, the disadvantages of the three processes are avoided, the technical problems that the anaerobic fermentation and the heavy metal of the compost product cannot be effectively controlled are solved, and the waste is really treated by recycling, harmlessness, reduction and economy; meanwhile, the defects of poor incineration economy when single raw materials of biomass or household garbage are insufficient and high energy consumption of drying and incineration of livestock and poultry excrement can be overcome.

(2) The synergistic resource utilization of various pollutants of biomass raw materials (such as regional straws), livestock and poultry manure (such as pig manure) and household garbage is realized; can obtain various byproducts of organic fertilizer, methane, steam and electric energy, can be fully utilized, has high resource utilization rate and good economic benefit, conforms to the concept of circular economy, and has technical and economic feasibility.

Drawings

FIG. 1 is a schematic diagram of the process for the synergistic utilization of agricultural and livestock wastes and domestic garbage and the control of heavy metals according to the present invention;

Detailed Description

The following detailed description of specific embodiments of the invention refers to the accompanying drawings.