Production of volatile fatty acids from sewage organic matter by combined bioflocculation and alkaline fermentation

Rungnapha Khiewwijit; Hardy Temmink; Alvaro Labanda; Huub Rijnaarts; Karel J Keesman

doi:10.1016/j.biortech.2015.08.112

Production of volatile fatty acids from sewage organic matter by combined bioflocculation and alkaline fermentation

Bioresour Technol. 2015 Dec:197:295-301. doi: 10.1016/j.biortech.2015.08.112. Epub 2015 Sep 1.

Authors

Rungnapha Khiewwijit¹, Hardy Temmink², Alvaro Labanda³, Huub Rijnaarts⁴, Karel J Keesman⁵

Affiliations

¹ Wetsus, European Centre of Excellence for Sustainable Water Technology, P.O. Box 113, 8900CC Leeuwarden, The Netherlands; Biobased Chemistry and Technology, Wageningen University, P.O. Box 17, 6700AA Wageningen, The Netherlands; Sub-department of Environmental Technology, Wageningen University, P.O. Box 8129, 6700EV Wageningen, The Netherlands. Electronic address: rungnapha.khiewwijit@wetsus.nl.
² Wetsus, European Centre of Excellence for Sustainable Water Technology, P.O. Box 113, 8900CC Leeuwarden, The Netherlands; Sub-department of Environmental Technology, Wageningen University, P.O. Box 8129, 6700EV Wageningen, The Netherlands.
³ Wetsus, European Centre of Excellence for Sustainable Water Technology, P.O. Box 113, 8900CC Leeuwarden, The Netherlands.
⁴ Sub-department of Environmental Technology, Wageningen University, P.O. Box 8129, 6700EV Wageningen, The Netherlands.
⁵ Wetsus, European Centre of Excellence for Sustainable Water Technology, P.O. Box 113, 8900CC Leeuwarden, The Netherlands; Biobased Chemistry and Technology, Wageningen University, P.O. Box 17, 6700AA Wageningen, The Netherlands.

PMID: 26342342
DOI: 10.1016/j.biortech.2015.08.112

Abstract

This study explored the potential of volatile fatty acids (VFA) production from sewage by a combined high-loaded membrane bioreactor and sequencing batch fermenter. VFA production was optimized with respect to SRT and alkaline pH (pH 8-10). Application of pH shock to a value of 9 at the start of a sequencing batch cycle, followed by a pH uncontrolled phase for 7days, gave the highest VFA yield of 440mgVFA-COD/g VSS. This yield was much higher than at fermentation without pH control or at a constant pH between 8 and 10. The high yield in the pH 9 shocked system could be explained by (1) a reduction of methanogenic activity, or (2) a high degree of solids degradation or (3) an enhanced protein hydrolysis and fermentation. VFA production can be further optimized by fine-tuning pH level and longer operation, possibly allowing enrichment of alkalophilic and alkali-tolerant fermenting microorganisms.

Keywords: Alkaline pH; Anaerobic fermentation; Bioflocculation; Volatile fatty acids; Wastewater treatment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bioreactors
Fatty Acids, Volatile / chemistry*
Fermentation
Flocculation
Hydrogen-Ion Concentration
Hydrolysis
Proteins / chemistry
Sewage / chemistry*

Substances

Fatty Acids, Volatile
Proteins
Sewage