不同发酵浓度对混合尾菜中温厌氧消化产甲烷特性及关键酶活性的影响OA

This study explored the effects of different mass fractions on the methane production characteristics and the activ-ities of key enzymes in the anaerobic digestion of mixed tail vegetables through batch experiments.The experiment set up three substrate concentration gradients with mass fractions of 4％(TA),5％(TB),and 6％(TC).Under the constant temperature condition of(35±1)℃,the system monitored key parameters such as the concentration of volatile fatty acids(VFAs),methane content,total organic carbon(TOC),total inorganic carbon(TIC),cumulative gas production,and the activities of urease and β-glucosidase.The fermentation of the tail vegetable ended after 48 days.The results showed that 1)The kinetic analysis indicated that the cumulative gas production at a mass fraction of 6％(TC)reached 375.5 L,which was 37.76％higher than that at a mass fraction of 4％(TA).Using the SGompertz model for fitting,the 6％mass fraction(TC)fitting had the best effect and showed a maximum methane production rate of 6.78 L·d-1,which was 19.79％higher than that of the experimental group with a 4％mass fraction(TA),and the hydraulic retention time was the shortest.2)The variation trend of VFAs concentration in the entire fermentation system was consistent with the varia-tion law of TOC,indicating that a mass fraction of 6％(TC)could provide a large amount of TOC to promote the synthesis of VFAs.At the end of anaerobic digestion,it was found that achieving a TOC reduction of 4244.11 mg·L-1 had the stron-gest ability to produce VFAs.The peak value reached 3160.45 mg·L-1.3)By analyzing urease and β-glucosidase,the peak values of urease and β-glucosidase at a mass fraction of 6％(TC)were 21.05 mg·L-1 and 2.52 mg·L-1 respectively,which increased by 74.25％and 13.57％respectively compared with a mass fraction of 4％(TA).The changes in total or-ganic carbon and volatile fatty acid content during the anaerobic digestion process can be revealed through enzyme activity,thereby increasing gas production and methane yield.Urease is the most active key enzyme activity indicator when methane production begins,while β-glucosidase is the key enzyme activity indicator for maximizing methane production.