A Research On Two-stage Anaerobic Fermentation Process Of Vegetable Leaves And Crop Straw

As the most important agricultural waste,tailing and crop straw,if discarded directly without treatment,not only cause the waste of resources,but also cause the pollution of the ecological environment in rural areas.Reasonable development and utilization of agricultural wastes such as tail vegetables and crop straws is conducive to the protection of the ecological environment in rural areas,and has great significance in promoting the development of circular agriculture.Using anaerobic fermentation to treat tailing and crop straw has the characteristics of good economy,no pollution and high utilization rate of resources.Through the study of the two-stage combined anaerobic fermentation process of tailing and crop straw,according to the anaerobic fermentation characteristics of tailing,the optimal fermentation process is proposed.The problem of difficult start-up,difficult seed introduction,easy acidification and low gas production rate of crop straw dry fermentation can be solved by spraying and soaking the tailing biogas slurry.After experimental research and data analysis,the following conclusions are drawn:1.Based on lettuce leaves and cabbage leaves as raw materials,the best technology of anaerobic fermentation of tailing vegetables was studied.Through the study of the parameters such as the best fermentation temperature,the best microbial inoculum amount and the best fermentation organic load,5L anaerobic fermentation bottle and 30L full-automatic anaerobic fermentation tank were used for the laboratory test.Under the condition of the best fermentation temperature of 35?and the best microbial inoculum amount of 30%,it was concluded that The maximum organic load of anaerobic fermentation was 4.03g.ts/l.d~4.17g.ts/l.d,HRT was about17.2d,the maximum gas production rate of raw material was 0.44l/g.ts,the maximum gas production rate of tank capacity was 1.81l/l.d,and the number of methanogenic archaea was maintained at 1.82×10~8/mL~2.12×10~8/mL.2.With corn straw as raw material,the experiment of straw dry fermentation was carried out,and the straw was compressed and packed,which not only saved the fermentation space,but also made it more convenient to import and export materials.With the tail vegetable biogas liquid as the microbial inoculum,the inoculation was carried out by means of spraying and soaking,which solved the problems of difficult start-up of straw dry fermentation and difficult transfer of materials,increased the gas production rate of raw materials and shortened the gas production cycle?In the laboratory,the start-up time of corn straw dry fermentation was accelerated to 1d~3d,the pH value was kept around 7.5,the gas production rate of raw materials reached334.26mL/g.ts,the peak gas production was advanced to 8d~16d,the gas production cycle was shortened to 40d~45d,and the number of methanogenic archaea was maintained at 1.56×10~8/mL~2.07×10~8/mL.3.The two-stage combined anaerobic fermentation process of tailing and crop,straw improves the organic load of tailing and the gas production rate of raw materials through microbial enhancement technology.The problem of dry fermentation of crop straw is solved by spraying and soaking the tailing biogas liquid,which shortens the gas production cycle and improves the gas production rate of raw materials.The biogas liquid and biogas residue after anaerobic fermentation are better ecological organic fertilizer.It is directly used for returning to the field and meets the requirements of ecological circular agriculture.