Hydrolysis–acidogenesis of food waste in solid–liquid-separating continuous stirred tank reactor (SLS-CSTR) for volatile organic acid production
Department of Biology
The use of conventional continuous stirred tank reactor (CSTR) can affect the methane (CH4) recovery in a two-stage anaerobic digestion of food waste (FW) due to carbon short circuiting in the hydrolysis–acidogenesis (Hy–Aci) stage. In this research, we have designed and tested a solid–liquid-separating CSTR (SLS-CSTR) for effective Hy–Aci of FW. The working conditions were pH 6 and 9 (SLS-CSTR-1 and -2, respectively); temperature-37 °C; agitation-300 rpm; and organic loading rate (OLR)-2g VS L−1 day−1. The volatile fatty acids (VFA), enzyme activities and bacterial population (by qPCR) were determined as test parameters. Results showed that the Hy–Aci of FW at pH 9 produced ∼35% excess VFA as compared to that at pH 6, with acetic and butyric acids as major precursors, which correlated with the high enzyme activities and low lactic acid bacteria. The design provided efficient solid–liquid separation there by improved the organic acid yields from FW.
Food waste, Hydrolysis–acidogenesis, CSTR, Solid- and hydraulic-retention time, Volatile fatty acids
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Link to Publisher's Edition
Obulisamy, Parthiba Karthikeyan, Selvam Ammaiyappan, and Woon Chung Jonathan Wong. "Hydrolysis–acidogenesis of food waste in solid–liquid-separating continuous stirred tank reactor (SLS-CSTR) for volatile organic acid production." Bioresource Technology 200 (2016): 366-373.