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|Title:||Enhanced volatile fatty acids (VFAs) production in a thermophilic fermenter with stepwise pH increase – Investigation on dissolved organic matter transformation and microbial community shift||Authors:||Chen, Yun
Zeng, Raymond J.
|Keywords:||Progressive pH Increase
|Issue Date:||2017||Source:||Chen, Y., Jiang, X., Xiao, K., Shen, N., Zeng, R. J., & Zhou, Y. (2017). Enhanced volatile fatty acids (VFAs) production in a thermophilic fermenter with stepwise pH increase – Investigation on dissolved organic matter transformation and microbial community shift. Water Research, 112, 261-268.||Series/Report no.:||Water Research||Abstract:||In this study, a mixture of primary and wasted activated sludge was fermented in a semi-continuous reactor aiming for enhanced volatile fatty acids (VFAs) production. The reactor was subjected to a stepwise pH increase from 7 to 10 during approximately 130 days of operation. The result revealed that the maximum acidification was obtained at pH 8.9 (21%) resulting in the maximum production of VFAs (423.22 ± 25.49 mg COD/g VSS), while the maximum hydrolysis efficiency was observed at pH 9.9 (42%). The high pH was effective in releasing dissolved organic matter (DOM) including protein, carbohydrate, building blocks and low molecular weight (LMW) neutrals. More LMW DOMs were released than high molecular weight (HMW) DOMs fractions at higher pH. pH 9.9 favored hydrolysis of HMW DOMs while it did not enhance the acidogenesis of LMW DOMs. The microbial community analysis showed that the relative abundance of phyla Actinobacteria and Proteobacteria increased with the increased pH, which may lead to the maximum hydrolysis at pH 9.9. At pH 8.9, class Clostridia (59.16%) was the most dominant population where the maximum acidification (21%) was obtained. This suggested that the dominance of Clostridia was highly related to acidification extent. The relative abundance of Euryarchaeota decreased significantly from 58% to 2% with increased pH.||URI:||https://hdl.handle.net/10356/86555
|ISSN:||0043-1354||DOI:||10.1016/j.watres.2017.01.067||Rights:||© 2017 Elsevier Ltd. This is the author created version of a work that has been peer reviewed and accepted for publication by Water Research, Elsevier Ltd. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.watres.2017.01.067].||Fulltext Permission:||open||Fulltext Availability:||With Fulltext|
|Appears in Collections:||CEE Journal Articles|
NEWRI Journal Articles
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