Abstract

For many years, sewage sludge has been processedfor methane production in anaerobic digestion reactors atwastewater treatment plants around the world. Sewage sludgeis produced in large quantities and is rich in biodegradableorganic materials, from which sugars (e.g., glucose) can beproduced, recovered and used as a substrate to supporthydrogen production through the Dark Fermentation (DF)process. DF is one of several methods used for bio-hydrogenproduction, whereby fermentative bacteria are used tohydrolyse organic substrates to produce hydrogen gas.Carbohydrates (sugars) is one of the main fermentablesubstrates for hydrogen production, and they are consideredthe most favourable substrate for fermentative bacteria (e.g.,Clostridium bacteria). Although sewage sludge is rich inorganic materials, still the complexity of its structure and lowcarbon/nitrogen ratio limits the bio-hydrogen production viaDF processes. Therefore, this paper addresses the impact ofEnzymatic Hydrolysis (EH) as a pre-treatment of sewage sludgeon enhancing the biodegradability and glucose content insewage sludge. The result shows that using the EH process aspre-treatment for sewage sludge, enhanced the glucose contentin sewage sludge and converted some of the macro sewage flocsto easy digestible micro flocs (glucose). Therefore, the substratebeing more favourable and easier to digest by bacteria in the DFreactor, enhanced the production of hydrogen and VFAs. Moreresearch needs to be done to find the optimum enzyme dosage,initial substrate concentration and operation temperature(especially when the enzyme is used inside the DF reactor).