阅读说明：本技术 一种利用瘤胃微生物生产挥发性脂肪酸的方法 (Method for producing volatile fatty acid by using rumen microorganisms ) 是由 靳文尧 于 2019-11-22 设计创作，主要内容包括：本发明属于资源与环境领域,公开了一种利用瘤胃微生物生产挥发性脂肪酸的方法。具体为：将来源于反刍动物瘤胃内固液混合物接种到预热的厌氧罐中,加入粉碎后的纤维素类生物质后开始稳定运行,厌氧罐出水经过旋流分离沉淀池,固体部分回流至厌氧罐,液体进入混凝沉淀池去除悬浮物后作为挥发性脂肪产品。本发明实现了纤维素类生物质废物生产挥发性脂肪酸,提高了反应效率,降低了产品成本。(The invention belongs to the field of resources and environment, and discloses a method for producing volatile fatty acid by using rumen microorganisms. The method specifically comprises the following steps: inoculating a solid-liquid mixture in a rumen of a ruminant into a preheated anaerobic tank, adding crushed cellulose biomass, then starting to operate stably, enabling water discharged from the anaerobic tank to pass through a cyclone separation sedimentation tank, enabling a solid part to flow back to the anaerobic tank, and enabling liquid to enter a coagulating sedimentation tank to remove suspended matters to be used as a volatile fat product. The invention realizes the production of volatile fatty acid from cellulose biomass waste, improves the reaction efficiency and reduces the product cost.)

1. A method for producing volatile fatty acid by using rumen microorganisms is characterized in that an anaerobic tank is preheated to 30-42 ℃; inoculating a solid-liquid mixture from the rumen of a ruminant into an anaerobic tank, wherein the inoculation volume fraction ratio is 1-20%; adding the crushed cellulose biomass with the particle size of 0.5-20mm into an anaerobic tank and starting to operate; when the efficiency of converting cellulose biomass into volatile fatty acid in the anaerobic tank reaches 50%, the degradation efficiency reaches 70%, and the hydrogen content is more than 5%, the system enters a stable operation stage; the stable operation process parameters of the anaerobic tank are as follows: the retention time is 3-8 days, the temperature is 30-42 ℃, the solid content is 1-3%, the pH value is 5.5-7.0, and the oxidation-reduction potential is less than-300 mV; enabling effluent of the anaerobic tank to enter a cyclone separation sedimentation tank, enabling 50-100% of precipitated solid to flow back into the anaerobic tank, and enabling the liquid to enter a coagulation sedimentation tank to remove suspended matters; the effluent of the coagulating sedimentation tank is a product containing volatile fatty acid.

2. The method for producing volatile fatty acids using rumen microorganisms according to claim 1, wherein the anaerobic tank is a total-mixed anaerobic reactor equipped with a stirrer and a hull breaking means.

3. The method for producing volatile fatty acids using rumen microorganisms according to claim 2, wherein the pulverized cellulosic biomass is introduced into an anaerobic tank, and a pre-conditioning method is used to uniformly mix the pulverized cellulosic biomass and the sewage at a ratio of 1-10% solids content, and then the mixture is pumped by a pump; or directly adding the crushed cellulose biomass into the anaerobic tank, and adding sewage by using a pump to ensure the operation technological parameters of the anaerobic tank.

4. The method for producing volatile fatty acids by using rumen microorganisms as claimed in claim 3, wherein said cellulosic biomass comprises but is not limited to municipal garden waste, kitchen waste and rural corn, rice, wheat, crop vines, and watercress.

Technical Field

The invention belongs to the field of resources and environment, and relates to a method for producing volatile fatty acid by using rumen microorganisms.

Background

The volatile fatty acid refers to short carbon chain organic acid formed by 1-6 carbon atoms and three elements of hydrogen and oxygen, comprises six elements of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid and the like, is widely used for producing microbial oil, Polyhydroxyalkanoates (PHA) and poly-beta-hydroxybutyrate (PHB) biological materials, or is used as a carbon source in a denitrification stage of sewage treatment. At present, the main processing and production mode is to use raw materials containing starch, sugar, protein and the like to prepare the food by anaerobic hydrolysis of microorganisms, and has the defects of high raw material cost, food competition with people and livestock and the like.

Cellulose biomass comprises garden waste, kitchen waste and the like in cities, and is mainly disposed by landfill and other modes at present; wastes such as stems and stems of corn, rice, wheat and the like, and crops such as vines, caucasians and the like in the agricultural production process are mainly recycled by returning to the field, burning for power generation and the like at present. These treatment methods can solve the problem of environmental pollution of cellulosic biomass temporarily, but all of them have problems of resource waste, low conversion efficiency, low added value of products, and the like.

Another characteristic of cellulosic biomass is that it is difficult to degrade by microorganisms due to its "three-dimensional binding" structure and the influence of crystalline cellulose. Rumen microorganisms are a general term of first intragastric microorganisms of ruminants, are a 'microbial treasury' of natural cellulose biomass fermentation, can be efficiently converted into substances such as volatile fatty acid and the like to be absorbed by animals, and further participate in tricarboxylic acid cycle to provide energy for organisms. If the bionic principle is adopted and the anaerobic hydrolysis theory is combined, a ruminant rumen fermentation system is simulated, urban and rural cellulose biomass waste is efficiently converted into volatile fatty acid in vitro, and the resource, harmless and high-value utilization ways of the cellulose biomass waste are effectively expanded.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for producing volatile fatty acid by using rumen microorganisms, which can efficiently convert cellulose biomass into volatile fatty acid, reduce resource waste and reduce the production cost of volatile fatty acid.

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

a method for producing volatile fatty acid by using rumen microorganisms comprises the steps of preheating an anaerobic tank to 30-42 ℃; inoculating a solid-liquid mixture from the rumen of a ruminant into an anaerobic tank, wherein the inoculation volume fraction ratio is 1-20%; adding the crushed cellulose biomass with the particle size of 0.5-20mm into an anaerobic tank and starting to operate; when the efficiency of converting cellulose biomass into volatile fatty acid in the anaerobic tank reaches 50%, the degradation efficiency reaches 70%, and the hydrogen content is more than 5%, the system enters a stable operation stage; the stable operation process parameters of the anaerobic tank are as follows: the retention time is 3-8 days, the temperature is 30-42 ℃, the solid content is 1-3%, the pH value is 5.5-7.0, and the oxidation-reduction potential is less than-300 mV; enabling effluent of the anaerobic tank to enter a cyclone separation sedimentation tank, enabling 50-100% of precipitated solid to flow back into the anaerobic tank, and enabling the liquid to enter a coagulation sedimentation tank to remove suspended matters; the effluent of the coagulating sedimentation tank is a product containing volatile fatty acid.

Furthermore, the anaerobic tank is a full-mixing type anaerobic reactor and is provided with a stirrer and a shell breaking device.

Further, the crushed cellulose biomass is added into an anaerobic tank, a pre-humidifying method can be adopted, and the crushed cellulose biomass and sewage are uniformly mixed according to the solid content of 1-10% and then pumped by a pump; or directly adding the crushed cellulose biomass into the anaerobic tank, and adding sewage by using a pump to ensure the operation technological parameters of the anaerobic tank.

Further, the cellulosic biomass includes, but is not limited to, municipal garden waste, kitchen waste and rural corn, rice, wheat, crop vines, and brassica rapa.

Compared with the prior art, the invention has the beneficial effects that:

by means of the method for simulating the rumen fermentation environment of the ruminant through preheating, stirring, refluxing and the like of the anaerobic tank, the number of bacteria and fungi OTU which can effectively degrade cellulose, hemicellulose and other components in rumen microorganisms is kept to be more than 20%, and the effectiveness and stability of the bacteria flora for producing volatile fatty acid by the anaerobic tank are guaranteed. In the stable operation stage of the anaerobic tank, the rumen microbial fermentation characteristics and the mechanism of producing volatile fatty acid by anaerobic fermentation are fully considered and combined, the efficiency of producing the volatile fatty acid by cellulose biomass per gram weight can reach more than 0.5g/g, the degradation efficiency reaches more than 75 percent, and the retention time can be shortened to 3-8 days from the traditional 10-20 days. The effluent of the anaerobic tank is a solid-liquid mixture, the solid and the liquid can be separated by the cyclone separator, and suspended matters in the liquid part are further removed by a coagulating sedimentation method, so that the subsequent process systems are smoothly connected. The invention realizes the production of volatile fatty acid from cellulose biomass waste, improves the reaction efficiency and reduces the product cost.

Drawings

FIG. 1 is a graph comparing the production of volatile fatty acids by the method of example 1 and the method of comparative example 1.

Detailed Description

The invention is described in more detail below with reference to specific examples, without limiting the scope of the invention. Unless otherwise specified, the experimental methods adopted by the invention are all conventional methods, and experimental equipment, materials, reagents and the like used in the experimental method can be obtained from commercial sources.