Evaluation of biohydrogen production potential from sewage sludge

Abstract

Owing to limited resources and emission of pollutants, hydrogen is a promising alternative to fossil fuels. Hydrogen is a clean energy that produces water instead of greenhouse gases when combusted. Furthermore, hydrogen has a high-energy yield (about 2.75 times that of hydrocarbon fuels). Biological hydrogen production from biomass is considered one of the most promising alternatives for sustainable green energy production and important solution to a sustainable power supply and is nowadays being seen as the versatile fuel of the future, with potential to replace fossil fuels. This process is able to solve two problems: The reduction of pollution from the uncontrolled degradation of waste and the generation of a clean alternative fuel. The treatment and disposal of sewage sludge generated in urban wastewater treatment plants are an important environmental problem. Unused, discarded biomass residues are a potential energy resource, which at present are not well managed and thus pose significant environmental problems. Recently, some studies are focusing on using the sludge to produce hydrogen by anaerobic fermentation. Sewage sludge from a wastewater treatment plant is biomass that contains large quantities of polysaccharides and proteins and thus is a potential substrate for producing hydrogen. Limited data addressing this topic show that the biohydrogen yield using waste sludge and anaerobic fermentation is rather low. Due to low hydrogen yield from the raw sewage sludge, a number of pretreatment approaches have been investigated. Pretreatment can increase the efficiency of anaerobic stabilization of sludge by hydrolyzing the insoluble organic matter to water. This study deals with the suitability of pretreated sewage sludge as the primary substrate for microbial H2 production and also may overcome certain important limitations of biological H2 production. © Springer International Publishing Switzerland 2014.