Hydrogen generation in microbial electrolysis cell feeding with fermentation liquid of waste activated sludge

• DOI: 10.1016/j.ijhydene.2012.04.090
• Publication Date: 2012-05-12T14:48:18Z
• Authors: Wenzong Liu; Shihching Huang; Aijuan Zhou; Guangyu Zhou; Nanqi Ren; Aijie Wang; Guoqiang Zhuang
• Keywords: Valerate; Microbial electrolysis cell; Dilution; Dark fermentation

Abstract The short-chain fatty acids (SCFAs) accumulated in waste activated sludge (WAS) fermentation was adopted as an alternative extra carbon source for biohydrogen production in microbial electrolysis cells (MECs). WAS was pretreated by bi-frequency ultrasonic and the highest SCFAs were accumulated at 3rd day. Three groups of tests were conducted in single chamber MECs for H2 production under different SCOD concentrations. SCOD removals were up to 60% at diluted influent, but reduced to 50% at original concentration. Highest H2 yield was 1.2 mL H2/mg COD at 2-fold dilution with 155% energy efficiency. Results showed that >90% of acetate and ∼90% of propionate were effectively converted to hydrogen, and next were n-butyrate and n-valerate (at dilutions), but