ABSTRACT
Large amounts of organic matter from wastewater are converted into waste activated sludge (WAS) during biological treatment processes in wastewater treatment plants (WWTPs) [1]. Anaerobic digestion of WAS has been widely applied to stabilize and reduce the volume of WAS as well as produce a renewable bioenergy resource in the form of methane [2-5]. The anaerobic digestion process generally consists four stages, i.e. hydrolysis, fermentation, acetogenesis and methanogenesis for methane production [6]. However, the application of anaerobic digestion is often limited
by the slow hydrolysis rate and/or poor biochemical methane potential (or degradation extent) of the WAS [7-11].
