Enhanced bioproduction of short-chain fatty acids by ionic liquid during anaerobic digestion of waste activated sludge
The application of anaerobic digestion of waste activated sludge is hindered by low production rate of short-chain fatty acids(SCFAs)and inefficient sludge solubilization and hydrolysis.To surmount these challenges,this study used ionic liquid to promote sludge solubilization.Effects of ionic liquid on sludge hydrolysis and SCFAs production were evaluated.The results showed that the addition of ionic liquid[Emim]OTF significantly enhanced sludge hydrolysis,increased SCFAs production,and inhibited gas production.At ionic liquid dosage of 0.1g/g VSS,the maximum SCFAs production was 226.4mg COD/(g TS),which was 3.75times that of the untreated sludge.Analysis of microbial diversity revealed that addition of ionic liquid[Emim]OTF enriched hydrolytic acid-producing bacteria and strengthened the sludge hydrolysis and acidification processes,which in turn led to the increase in SCFAs production.