Enhanced short-chain fatty acids production from waste activated sludge by sophorolipid: Performance, mechanism, and implication
Author(s)
Xu, Qiuxiang
Liu, Xuran
Wang, Dongbo
Liu, Yiwen
Wang, Qilin
Ni, Bing-Jie
Li, Xiaoming
Yang, Qi
Li, Hailong
Griffith University Author(s)
Year published
2019
Metadata
Show full item recordAbstract
It was found in this study that the presence of sophorolipid (SL) enhanced the production of short-chain fatty acid (SCFA) from anaerobic fermentation of waste activated sludge (WAS). Experimental results showed that with an increase of SL addition from 0 to 0.1 g/g TSS, the maximal SCFA yield increased from 50.5 ± 4.9 to 246.2 ± 7.5 mg COD/g VSS. The presence of SL reduced the surface tension between hydrophobic organics and fermentation liquid, which thereby accelerated the disintegration of WAS and improved the biodegradability of the released organics. SL promoted the carbon/nitrogen ratio of the fermentation system, ...
View more >It was found in this study that the presence of sophorolipid (SL) enhanced the production of short-chain fatty acid (SCFA) from anaerobic fermentation of waste activated sludge (WAS). Experimental results showed that with an increase of SL addition from 0 to 0.1 g/g TSS, the maximal SCFA yield increased from 50.5 ± 4.9 to 246.2 ± 7.5 mg COD/g VSS. The presence of SL reduced the surface tension between hydrophobic organics and fermentation liquid, which thereby accelerated the disintegration of WAS and improved the biodegradability of the released organics. SL promoted the carbon/nitrogen ratio of the fermentation system, enhancing the conversion of proteins in WAS. Moreover, SL suppressed severely the activities of methanogens, probably due to the drop of pH caused by SL addition. Amplicon sequencing analyses revealed that SL increased the abundance of hydrolytic microbes such as Bacteroides sp. and Macellibacteroides sp., and SCFA producers (e.g., Acinetobacter sp.).
View less >
View more >It was found in this study that the presence of sophorolipid (SL) enhanced the production of short-chain fatty acid (SCFA) from anaerobic fermentation of waste activated sludge (WAS). Experimental results showed that with an increase of SL addition from 0 to 0.1 g/g TSS, the maximal SCFA yield increased from 50.5 ± 4.9 to 246.2 ± 7.5 mg COD/g VSS. The presence of SL reduced the surface tension between hydrophobic organics and fermentation liquid, which thereby accelerated the disintegration of WAS and improved the biodegradability of the released organics. SL promoted the carbon/nitrogen ratio of the fermentation system, enhancing the conversion of proteins in WAS. Moreover, SL suppressed severely the activities of methanogens, probably due to the drop of pH caused by SL addition. Amplicon sequencing analyses revealed that SL increased the abundance of hydrolytic microbes such as Bacteroides sp. and Macellibacteroides sp., and SCFA producers (e.g., Acinetobacter sp.).
View less >
Journal Title
Bioresource Technology
Note
This publication has been entered into Griffith Research Online as an Advanced Online Version.
Subject
Water treatment processes
Environmental sciences
Bacteriology