Anaerobic Co-Digestion of Water Hyacinth and Sheep Waste

Water hyacinth (WH) and sheep waste (SW) can be used to generate energy which could save on the fossil fuels conventionally used as source of energy. In this study, the possibility was explored to mix water hyacinth with sheep waste in different combinations for anaerobic co-digestion, so that energy can be generated as biogas and at the same time digested sludge can be used as fertilizer for agricultural applications. Pretreatment of water hyacinth was done by alkali method. Anaerobic co-digestion was carried out in mesophilic temperature range of 30 degrees C to 37 degrees C with different fermentation slurries of 8% total solids. Co-digestion was carried for a retention period of 60 days. The gas produced was collected by the downward displacement of water, and was subsequently measured and analyzed. Fermentation slurry SW3 (mixing ratio of 4: 12.01: 83.90 for Water Hyacinth: Sheep Waste: Water) was found to be optimum, which gave the highest biogas yield of 0.36 l/gVS. with composition 60.84% % CH4, 21.53% CO2 and 17.63% others (H-2, N-2, H2O and H2S). The overall results showed that blending water hyacinth with Sheep waste had significant improvement on the biogas yield. (C) 2014 Published by Elsevier Ltd.