Study On The Anaerobic Co-digestion Characteristics Of Steam Explosion Corn Stover Wastewater And Cattle Manure

The lignocellulose in the corn stover can be separated into three components in high-temperature and high-pressure steam explosion environment,thereby obtaining cellulose,hemicellulose and lignin which are convenient for industrial use.In the process of steam explosion,the mass ratio of corn stalk to influent water is generally 1:2 ～1:4,which leads to a large amount of high-temperature organic wastewater,namely steam explosion corn stover wastewater(CSTW).The anaerobic co-digestion of CSTW and cattle manure can not only use the heat and organic matter in the CSTW,but also achieve the purpose of harmless treatment of pollutants,which is of great significance for the production of biomass energy and environmental protection.However,furfural and 5-hydroxymethylfurfural in the CSTW can inhibit the activity of methanogenic microorganisms,at the same time,the characteristics of the CSTW and the reaction conditions of anaerobic co-digestion with cattle manure have not been clear yet.Therefore,exploring the characteristics of anaerobic co-digestion of CSTW and cattle manure is essential for the sufficient utilization of CSTW.To this end,a batch test of anaerobic co-digestion of CSTW and cattle manure was conducted primarily to explore the effect of CSTW contents on the methane production performance,and then continuous feeding test and intermitte nt feeding test were designed and conducted to prove the influence law of organic load on anaerobic co-digestion,and determine the optimal organic load for methane production in the co-digestion system.The main research results and conclusions were:(1)The test group with a CSTW addition of 40 g/L had the best gas production performance among all the batch test groups of anaerobic co-digestion,its cumulative methane production was2569.79 m L,which was 20.86% higher than the control group,and the TS a nd VS degradation rates 35.2% and 35% higher than that of the control group,respectively.The results show that the proper amount of CSTW in the co-digestion system can promote the degradation of the substrate and improve the utilization rate of organic matter in the substrate,thereby increasing the methane production.(2)In the test of continuously increasing the organic load,the test group with the addition of40 g/L of CSTW had better methanogenic performance and organic load-bearing capacity than the other test group and the control group.In this test group,when the daily input and output feeding volume was 123.08 g,namely the organic loading rate was 13.94 g/(L·d),the daily methane production reached the highest 629.19 m L,which was 1.57 times that of the control group,at the same time the volume gas production rate reaches 1.28 L/(L·d)and the methane content was61.69%,which was much higher than the control group’s 45.8%.It means that adding the appropriate amount of CSTW improves the methane production and the quality of biogas produced.(3)In the test of intermittently increasing the organic load,the test group with an intermittent time of 1 day had higher methane production efficiency and substrate degradation rate.The total amount of methane produced during the cycle was 888 m L,which 436 m L more than the control group.And the total volume gas production rate was 1.53 L /(L·T),which was 0.52 L /(L·T)more than the control group,and the daily methane production was 162.26 m L less tha n the test group that continuously increases test under the same organic load.The TS degradation rate of the group during the intermittent 1 day feed and discharge was 60.4%,which was 20% higher than the control group,and 17.63% higher than the test group that continuously increased the feed and discharge under the same organic load.