Biohydrogen production from chemical wastewater as substrate by selectively enriched anaerobic mixed consortia: Influence of fermentation pH and substrate composition

Bioconversion of de-oiled Jatropha Waste (DJW) to hydrogen and methane gas by anaerobic fermentation: Influence of substrate concentration, temperature and pH

“…However, the pH change in all the experiments was not coincided with the concentration of VFA, contrarily showed a distinct profile. A similar case was observed [33] and the pH drop is not significantly varied, only 0e0.5 unit from initial pH. The highest pH drop (0.4 AE 0.1) was at 55 C when the DJW concentration was 200 g/L.…”

Integration of acidogenic and methanogenic processes for simultaneous production of biohydrogen and methane from wastewater treatment

“…The pH range of 5.5-6 was considered to be ideal to avoid both methanogenesis and solventogenesis [39,56] in addition to effective H 2 generation. By maintaining the pH around 6 compared to a near neutral pH the conversion efficiency (of fermentative H 2 production) can be increased [6,[13][14]55]. AcSBBR outlet pH varied between 3.2 and 4.4 during the operation which might be attributed to the production of acid (Fig.…”

“…In recent times a great deal of attention is focused on hydrogen (H 2 ) production by biological route as an alternative and viable method by research fraternity [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. H 2 has been recognized as a promising, green and ideal energy carrier of the future due to its high energy yield (122 kJ/g) and clean, efficient, renewable, sustainable and recyclable nature [16].…”

“…Typical H 2 yield range from 1 to 2 mol of H 2 /mol of glucose, and results in 80-90% of the initial chemical oxygen demand (COD) remaining in the wastewater in the form of various volatile organic acids (VFAs) and solvents, such as acetic, propionic, butyric acids and ethanol [1]. Even under optimal conditions about 60-70% of the original organic matter remains in solution [12][13][14][15]. In spite of theoretical conversion efficiency of 33%, only 15% of the energy from the organic source is typically obtained in the form of H 2 [1,11,38,39].…”

Meeting the U.S. renewable fuel standard: a comparison of biofuel pathways

“…shallow ponds or tanks that can be circular or parallel raceway ponds (PRPs)] or in closed photobioreactors (PBRs). Most of the cultivation of algae is done in PRPs because of their low construction and operating costs (Briggs, 2004;Li et al, 2007;Venkata Mohan et al, 2007a,b Evangelista et al, 2008Graham et al, 2008;González-Fernández et al, 2011). PBRs are contained, closely controlled systems in which an ideal environment is maintained to ensure high and stable production levels of algae (Chisti, 2007;Hu et al, 2006;.…”