Adding Biochar In Anaerobic Digestion Of Dairy Manure Dung Can Strengthen Biogas Production

With the rapid development of animal husbandry,the bulk deposition and environmental pollution problems caused by centralised breeding are becoming more and more serious.At present,there are various weaknesses in the traditional treatment of cow dung,and the preparation technology of biogas using anaerobic digestion of cow dung is the best solution.However,the key problem of cow dung biomass energy conversion is low processing efficiency and low gas yield.In this essay,the anaerobic digestion process of cow dung was strengthened on the basis of small scale batch anaerobic digestion system employing biofortification which should be easy to obtain and low cost.Controlling the concentration of cerium in the fermentation system can improve the gas production of anaerobic digestion.Biochar at a specific temperature was added to the fermentation system in a certain proportion to enhance the gas production of anaerobic digestion.The main work are as follows: 1.The firing process of diary-manure-derived biochar was studied.After grinding,drying,burning and other methods,the raw material cow dung is fired into cow dung biochar.The cow dung biochar with can be obtained by adjusting the firing temperature of cow dung biochar.By adding cow dung biochar into the anaerobic digestion system,the best firing temperature and amount of biochar were determined by the change of methane accumulation.It is shown that the cow dung biochar has the ability to improve the anaerobic fermentation to produce methane.The strongest reinforcement effect can be realized using 400℃to fire the cow dung biochar and adding 30% the quantity of dry sludge weight.2.The firing process of mushroom-substrate-derived biochar was studied.After grinding,drying,burning and other methods,the raw material fungus chaff is fired into fungus chaff biochar.The fungus chaff biochar different feature can be obtained by adjusting the firing temperature of fungus chaff biochar.By adding fungus chaff biochar into the anaerobic digestion system,the best firing temperature and amount of biochar were determined by the change of methane accumulation.We found that the fungus chaff biochar has the ability to improve the anaerobic fermentation to produce methane.The strongest reinforcement effect can be realized using 550℃to fire the cow dung biochar and adding 30% the quantity of dry sludge weight.3.The effect of the cerium on gas production using anaerobic digestion of cow dung was studied through the contrast experiment of the different concentration gradient.The results show that the highest biogas production will achieved when we add 0.3μmol /Lthe rare earth cerium in the whole fermentation system.Compared with the blank controller,biogas and methane production increased by 20.3% and 22.34%.At the same time,anaerobic fermentation was carried out on the substrate of fungus chaff with the same concentration of compost.The treatment group with 0.3μmol /L of cerium showed a 26.17% increase in biogas production compared to the blank controller,and a 29.67% increase in methane production compared to the blank controller.4.Previous experiments showed that both biochar and cerium can enhance anaerobic fermentation to produce biogas.Using cerium as a modified material to change the properties of biomass,the rare earth modified biochar was prepared.A single biochar enhanced group and a Rare earth modified biochar enhanced group were designed.Compared with the blank controller,the biogas production of the rare earth modified biochar enhanced groups using cow dung as substrate was increased 49.41% and the methane production was increased 58.41%.Compared with the single biochar enhanced group,the biogas production of the rare earth modified biochar enhanced groups was increased 10.86% and the methane production was increased by 50.02%.