THE EFFECT OF DILUTE ALKALINE-AUTOCLAVING PRETREATMENT IN ENHANCING THE BIODEGRADABILITY OF LIGNOCELLULOSIC GARDEN WASTE

摘要

In Victoria, Australia, organic waste makes up approximately 50% of the average household municipal solid waste. All organic matter is a potential feedstock for anaerobic digestion however there remains a large proportion that is underutilised. Garden waste (GW) is one such lignocellulosic material with a complex cellulosehemicellulose- lignin structure making it resistant to degradation. Dilute alkaline-autoclaving (A-A) pretreatment was performed on GW at various particle sizes (unground and ground <10mm) and NaOH concentrations (0.5%, 1.0%, and 2.0% w/w), in order to assess their effects on enhancing biogas production. Batch tests showed the highest methane yield (213.70 L/kg VS) was obtained from ground GW treated at 1.0% NaOH, a 214.2% increase from untreated GW. FTIR spectroscopy was used to measure cellulose total crystallinity index (TCI), with results showing a correlation between enhanced biogas yield and reduction in TCI, with TCI 1.4973 for ground 1.0% NaOH in comparison to TCI 1.9023 for untreated GW. The findings so far have shown promise for A-A pretreatment in converting GW from a waste material to a value-added resource with the potential for use as a feedstock for bioenergy production.