The degradation of cellulose and lignocellulosic material was investigated in simulated landfill column reactors under sulfate reducing and methanogenic conditions. In the sulfate reducing reactors, methane gas production was effectively suppressed. The carbon dioxide produced during the sulfate reduction was dissolved in leachate as IC, leading to low carbon dioxide emission from sulfate reducing reactors. Higher COD in the leachate from the sulfate reducing reactors was probably due to higher solubilization rate of cellulose and lignocellulosic material. In a batch experiment, the hydrolysis of Avicel-cellulose, filter paper and newspaper was faster under sulfate reducing conditions. The percentage of organic carbon biodegradation in sulfate reducing conditions was higher than that in methanogenic conditions. (C) 1997 IAWQ. Published by Elsevier Science Ltd.