| Rural breeding of Dali Erhai Lake basin is on the rise and livestock manure production continues to increase,especially the dairy industry flourished in the northern basin of Erhai Lake,resulting in a large rural area non-point source pollution and threating to the water qualities of Erhai Lake.Erhai pollution control is around the corner,so to control non-point source pollution has been imperative,and resource utilization of livestock manure is one of the important means to address nonpoint source pollution.Anaerobic fermentation has both social and economic benefits and environmental benefits.With anaerobic fermentation of livestock manure,the environmental pollution in rural areas can reduce and provide biogas,while the residue after fermentation is fertilizer.However,lignocellulose is difficult to digest by microorganism,causing anaerobic fermentation rate-limiting step in the whole process,lignocellulose degradation in conventional anaerobic fermentation process is inefficient,and found a method for improving the efficiency of lignocellulose degradation is particularly important.The characteristics of mechanical grinding,electrochemical conditions and hydrothermal pretreatment in anaerobic fermentation of cow manure are discussed,the specific are as follows:1.Mechanical grinding effect on anaerobic fermentation of cow manure are significantly.With decreasing particle size,volume and quality of biogas production by anaerobic fermentation overall upward trend,the gas production of 60 mesh group and 80 mesh group can reach about 6800mL,that significantly higher than the large particle size of 20 mesh group and 40 mesh group,indicating that the cumulative gas production,TS gas production rate and raw material conversion rate are improved significantly with a smaller particle size of cow manure in anaerobic fermentation process.2.hydrothermal pretreatment effect on anaerobic fermentation is obviously,after temperature of 150 ? and 200 ? treatment,the cumulative gas production and TS produced gas rate and raw materials rate are obviously higher than the temperature of 50? and 100? group,CH4 content value is increases in 50 ?,1500? range but reduced in 150 ?-200 ?,Description of high hydrothermal pretreatment temperature can affect the quality of biogas,so the optimum temperature of 150 ? for hydrothermal treatment.Hydrothermal pretreatment time of 10min,and 30min for two groups,the cumulative gas production,TS gas production rate and raw material conversion rate of 34min groups are highter than the 10 min groups.3.With electrochemical conditions added in anaerobic fermentation,gas production and CH4 content have significant effects.First is daily production volume of gas production change significantly,added to the positive power supply anaerobic fermentation system,the gas peak comparison with blank group is significantly low,but the other time of daily gas are stable than the blank group,the cumulative gas production is slightly higher than the blank group.Anaerobic fermentation system with the negative power supply,there are mang daily gas production peaks and vallies,but will soon be able to recover,and the cumulative production gas is significantly higher than the other two groups,and its maintain a high level CH4 content.4.Joint hydrothermal pretreatment technology and electrochemical condition for anaerobic fermentation is better than separate used hydrothermal pretreatment or electrochemical condition.First change is gas production trend,daily gas peaks are lower than single hydrothermal pretreatment groups,and exist vally period,but the peak continued a long time,and overall gas production are smooth.Second,joint groups with higher total produvtion,TS produced gas rate and raw materials into rate.Third,biogas quality with temperature of 150 ? pretreatment is the best.5.The degradation reaction mechanism of electrically assisted anaerobic fermentation system is preliminarily disscussed. |
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