Vegetable Waste Performances Of One-Phase Anaerobic Digestion

A large amount of vegetable waste produces annually in China, which is the main source of decay, odor and leachate due to their high volatile solids and moisture content.Nowadays,the practical treatments are mainly landfill,incineration,compost and anaerobic digestion. Compared to the other technologies,anaerobic digestion is the most effective to reduce the amount of vegetable waste and produce biogas for energy recovery.The research on different process parameters of the biogas production from vegetable waste by anaerobic fermentation is significant for the resource recovery of vegetable waste.Moreover,the residues produced by anaerobic fermentation can be used with various purposes. This research focuses on the research on different process parameters of the biogas production from vegetable waste by anaerobic fermentation. The main contents of the paper are as follows:The subject first selected the school cafeteria waste for anaerobic digestion suitable analysis. General classification of the vegetable waste, selecteding representative samples to analysis composition, including moisture, total solids, volatile solids, cellulose, hemicellulose, lignin, total carbon, total nitrogen, carbon and nitrogen ratio, soluble sugar, starch, fat, titratable acidity, total K, total P, total Na. Fruit and vegetable derived stem and leaf vegetables is more suitable for anaerobic digestion, Compared summer vegetables, spring vegetables is more suitable for anaerobic digestion.Then this study carried out batch experiments to select the appropriate inoculum.Then vegetables waste mixed pig manure at 35℃, in the single-phase reactor for semi-continuous anaerobic digestion experiments. Studyed organic loading limit, and gas production under different loadings, digestion performance, system stability, system energy consumption. The limit of organic load was 2.5gVS·L-1·d-1, gas production of 1.75gVS·L-1·d-1 is the best performanceTo further enhance the organic load, improved reactor and process conditions, the vegetable waste and anaerobic sludge were mixed in semi-continuous single-phase experiments at 35℃. Analysised different organic loading effect on the anaerobic digestion process, and the gas production performance, digestibility, material flow changes, the system stability. The limit of organic load was 3.5gVS·L-1·d-1, load 2.75gVS·L-1·d-1 of the best gas properties.Construction of molecular biology methods 16S rDNA clone library, analysis of different load single-phase anaerobic digestion of vegetable waste system, microbial community structure and succession of dominant bacteria in the digestive system of rule by microorganism-rich, high degree of diversity was with time and changes in operating conditions, flora structure has greatly changed. OLR 1.75 bacteria belonging to the major advantages of thick-walled bacteria (Firmicutes), Bacteroides (Bacteroidetes), Proteus (Proteobacteria) gate, the ratio was 32.3%, 22.6%,22.6%. OLR 2.0 dominant bacteria belong to thick-walled bacteria (Firmicutes), Bacteroides (Bacteroidetes), green curved bacteria (Chloroflexi) gate, the ratio of 29.5%,15.9%,18.2%. OLR 2.5 dominant flora belonged to Bacteroides (Bacteroidetes), each bacteria (Synergistetes) door.