BioChem - DOS

Production of volatile fatty acids by fermentation of waste activated sludge pre-treated in full-scale thermal hydrolysis plants

Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformations, production technologies

Morgan-Sagastume, F.; Pratt, S.; Karlsson, A.; Cirne, D.; Lant, P.; Werker, A.

This work focuses on fermentation of pre-treated waste activated sludge (WAS) to generate volatile fatty acids (VFAs). Pre-treatment by high-pressure thermal hydrolysis (HPTH) was shown to aid WAS fermentation. Compared to fermentation of raw WAS, pre-treatment enabled a 2-5x increase in VFA yield (gVFA<SUB>COD</SUB>gTCOD<SUP>-1</SUP>) and 4-6x increase in VFA production rate (gVFA<SUB>COD</SUB>L<SUP>-1</SUP>d<SUP>-1</SUP>). Three sludges, pre-treated in full-scale HPTH plants, were fermented. One was from a plant processing a mix of primary sludge and WAS and the other two from plants processing solely WAS. The HPTH plants solubilised suspended matter, evidenced by a 20-30% decrease in suspended solids and an increase of soluble COD : total COD from 0.04 to 0.4. Fermentation of the three sludges yielded similar VFA concentrations (15-20gVFA<SUB>COD</SUB>L<SUP>-1</SUP>). The yields were largely independent of retention time (1d-6d) and temperature (42<SUP>o</SUP>C, 55<SUP>o</SUP>C). Also, the product spectrum depended mostly on the composition of the sludge rather than on operating conditions.

2011

Elsevier Applied Science

0960-8524

102

3

pp.3089-3097

10.1016/j.biortech.2010.10.054

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART55191999

Fermentation; Thermal hydrolysis; Waste activated sludge; VFA; Sludge pre-treatment