Biogas production from an anaerobic pond treating domestic wastewater in Burkina Faso

Abstract

The production of biogas and its composition from an anaerobic pond treating domestic wastewater have been studied in the Sudano-Sahelian climate of Burkina Faso. The biogas production was measured from March 2010 to March 2011 using a floating static chamber, and the composition was analysed using a micro-gas chromatograph. The composition of biogas produced was relatively constant with time. The major component of the biogas by volume was CH4 which accounted for an average of 80.5%, N2 for 11.8%, O2 for 5% and CO2 for 2.5%. The mean areal production rates of biogas and methane respectively were 121 and 97 L m-2 d-1. The mean methane production rates were 248 L kg-1 COD removed and 588 L kg-1 VSS removed. The average daily volume of biogas and its corresponding methane were 5.73 and 4.63 m3 d-1, respectively, equivalent to a ratio of 7.3 m3 CH4 per capita-year. The conversion of this methane production to electricity could reduce the CO2 equivalent greenhouse gas emission from petrol combustion. This study revealed that the conversion of an anaerobic pond to an anaerobic lagoon digester with the capture and reuse of biogas would be an interesting option for wastewater treatment in the warm conditions of Sudano-Sahelian climate of Burkina Faso.