Effect of Ultrasonication On Pulp Waste Solubilization and Enhancement of Hydrogen Production in Batch Study

Batch anaerobic studies were conducted to study the effect of ultrasonication as a pretreatment method for pulp waste prior to bio-hydrogen production. Ultrasonication pretreatment of pulp waste was evaluated by sonicating 200 mL of waste at specific energies ranging from 500 to 30000 kJ/. Batch experiments were designed, based on food to microorganisms' ratio (F/M) of 4 based on total chemical oxygen demand (TCOD) of the substrate and volatile suspended solids (VSS) of the seed, to evaluate the effect of ultrasonication on the ultimate hydrogen production as well as hydrogen yield. The seed was primary anaerobic digested sludge form a municipal wastewater treatment plant. Hydrogen gas production was calculated using gas composition in the headspace and the total volume of biogas produced. The correlation between sonication energy and increase in both hydrogen production and hydrogen yield was determined. Liquid samples were analyzed for soluble metabolites i.e. volatile fatty acids. Mass balance closures were undertaken to validate the results based on TCOD.