Co-Digestion of Water Hyacinth and Duck Manure for Potential Low-Cost Biogas Production by Rural Communities

Leftover harvested water hyacinth biomass and duck manure can create waste management issues. As they are readily abundant and available, potential co-digestion of both waste sources for biogas production is explored as a waste-to-energy approach for a rural fishermen community. Seven 19-L do-it-yourself bioreactors are constructed with four different feedstock mixing ratios. The mixing ratios of water hyacinth to duck manure are varied at 70:30, 50:50, and 30:70, and are conducted in duplicate. One reactor utilizing 100% water hyacinth as feedstock acts as the control. Biogas production is measured daily for 50 days through the water displacement method. Variations in pH and chemical oxygen demand levels are monitored weekly. The results show that the highest biogas production is from the mixture of water hyacinth to duck manure at a 70:30 ratio (p < 0.05), with a volume of cumulative gas produced at 4.27 L that can be well simulated through the logistic function kinetic model (R-2 = 0.965). The biogas produced consists of methane, carbon monoxide, and hydrogen sulfide. The findings prove the potential of water hyacinth and duck manure as feedstocks for biogas production as one of the waste management solutions that can be practiced by the community.