Evaluation of Biogas Production by Anaerobic Digestion of Duckweed (Lemna minor) and Cattle Manure

Abstract

This study entailed evaluation of biogas production by anaerobic digestion of duckweed ( Lemna minor ) a plant that can be made easily available as much cheaper feedstock and cattle manure. Total solids, volatile solids, and organic carbon content of duckweed and cattle manure and pH of the slurries were determined using standard procedures. Three sets of plastic bottles were interconnected through connecting tube method. Digestion of duckweed to cattle manure in different percentage ratio (100:0, 75:25, 50:50, 25:75, 0:100) was performed respectively each in triplicates at 38 0 C temperature for 30 daysatAmbo University plant Science Department laboratory. The cumulative biogas production in milliliters from 100% duckweed, 75% duckweed and 25% cattle manure; 50% duckweed and 50% cattle manure; 25% duckweed and 75% cattle manure, and 100% cattle manure was found to be 1015.5, 1040, 1159, 1206, and 862, respectively. Statistical analyses indicated significant differences between means of the physico-chemical parameters determined before and after anaerobic digestion (P<0.05) in all samples. The result revealed the attractive potential of duckweed as a feedstock in biogas production which peaked when the plant was co-digested with cattle manure at ratio of 25% to75%. Keywords : Biogas, Renewable Energy, Cow Manure, Duckweed, Rumen Fluid DOI: 10.7176/JETP/11-2-01 Publication date: March 31 st 2021