Performance of a composite bioactive membrane for enhanced BioH2 production and capture from wastewater

Water and wastewater treatment accounts for 3% to 4% of the annual energy demand in the US. The opportunities for waste to energy conversion using anaerobic technologies are abundant, especially if applied to overcome the actual energy demand of wastewater treatment. In this study, a composite bioactive membrane was tested to recover clean energy from wastewater. Hollow fiber membranes were functionalized using encapsulated acidogenic bacteria to simultaneously produce and capture H2 from waste streams. Under anaerobic conditions and pH from 4.5 to 5.5, 5% of the maximum H2 molar yield (i.e., 4 holes H2/g hexose) was recovered from synthetic sewage. The H2 capture efficiency was improved by coating the modules with silica gel, resulting in 25% increase in H2 production. These results suggest that about 2.5 kWh/m3 excess energy could be generated from the treated influent in a wastewater treatment facility. To our knowledge, this study is the first to report efficient production/capture of H2 from wastewater using bioactive membranes.