Study On The Effect Of Biochar On Promoting Anaerobic Digestion Of Food Waste

At present,a large amount of food waste needs to be treated and disposed reasonably.Anaerobic digestion can efficiently degrade food waste and convert it into biogas,realize the recovery of biomass energy and has considerable economic value.The biochar material has a prominent pore structure,abundant surface functional groups and easy to obtain.In this paper,biochar is added to the anaerobic digestion device of food waste,and the related process of promoting the anaerobic digestion of food waste is analyzed.The specific conclusions of the study are as follows:Correlative characterization and analysis of corn stalk biochar were carried out and used in food waste anaerobic digestion equipment.Compared with the control group,the 300 ℃corn stalk biochar reactors,400 ℃ corn stalk biochar reactors,and 500 ℃ corn stalk biochar reactors of the experimental group increased the cumulative methane output by 172.8%,203.5%,160.0%.The 400 ℃ corn stalk biochar reactors showed the lowest volatile fatty acid and ethanol concentration of 4818 mg COD/L.The 400 ℃ corn stalk biochar is a biochar with more redox-active organic functional groups,which can enrich Petrimonas and Anaerolineaceae that transfer electrons to materials.In the reactor with biochar,the methanogens Methanosarcina and Methanothrix,which can use acetic acid to directly accept electrons through DIET to reduce carbon dioxide to methane,have higher abundances than the control group.The effect of biochar prepared from two raw materials of wheat straw and corn straw on the anaerobic digestion process of food waste was compared.Biochar of different raw materials showed different temperatures for the highest cumulative methane production.The BC2 reactor showed the highest cumulative methane production of 18.3 L,was 6.6% and3.6% higher than reactors with corn stalk biochar at 300 ℃ and 500℃.The BC4 reactor showed the highest cumulative methane production of 18.0 L,which was 6.4% and 5.8%higher than reactors with the wheat straw charcoal at 400 ℃ and 500 ℃.The volatile fatty acid content of the BC1 reactor and BC6 reactor were reduced by 68.7% and 63.4%respectively compared with the control group.The two kinds of biochar that showed the best methanogenic effect were corn stalk biocharl at 400 ℃ and wheat stalk biochar at 300 ℃.