Potential of Biogas Production from Floating Aquatic Weeds

Abstract

This study investigates the potential of biogas production from water hyacinth, water lettuce and water fern. Laboratory experiments were carried out at the Faculty of Agriculture laboratory, University of Benin, Nigeria. The aquatic weeds which are major constituents of the substrate were contained in the conical flasks used as digester. The cow dung and aquatic weeds were mixed in the ratio of 1:1; 1:2; 1:3; 1:4; and 1:5 in the different samples used for each of the three aquatic weeds and gas produced measured.The results obtained showed that no gas was produced in any of the flasks containing the aquatic weed within 21days. Gas production was however recorded in those with cow dung alone which gave 302ml of biogas within the 21 days retention period with an average of 21ml of gas produced within the active 14 days of production. The results also showed variations in gas production between daytime and night hours with minimal gas production recorded at night hours and peak production during the daytime. It was concluded that cow dung requires shorter retention time to initiate production of biogas when compared with that of the aquatic weeds and therefore can be used to sustained biogas production in aquatic weed at the early stage.