Selection of pretreatment method for enriching hydrogen-producing bacteria using anaerobic sewage sludge with three different substrates.

ABSTRACTThe pretreatment of anaerobic sewage sludge by different methods (acid, base, Ethyline Diamine Tetra Acetic Acid (EDTA), chloroform, ammonia, heat-shock, aeration, microwave oven and chloroform) were conducted in batch tests to evaluate and compare their suitability in the enrichment of hydrogen-producing bacteria from three different carbon sources (glucose, sucrose and starch). Among the pretreatment methods, heat-shock and alkali show the higher hydrogen production at 6.5 initial pH and 35°C using 5 g/l substrate concentration. The combination of heat and alkali pre-treatment found to be the maximal hydrogen content of 71%, hydrogen production potential of 310 ml/l (1.73 mol/kg COD[chemical oxygen demand]), hydrogen production rate of 51.7 ml/h/l, hydrogen yield of 2.27mol/mol glucose and substrate degradation efficiency of 70%.