Effect of nickel on biological methane generation from a laboratory poultry waste digester

Abstract
Nickel added in concentrations as low as 10μM significantly increased biogas production in a laboratory poultry waste digester utilizing excreta from laying hens as the organic energy source. It was shown that the initial rate of biogas production increased as early as 4 h after the addition of nickel to the laboratory cultures. Analysis of the excreta for nickel content prior to addition of exogenous NiCl2 showed appreciable amounts of nickel present. The data indicate that nickel naturally present in layer excreta is suboptimal or unavailable to the bacteria for biogas production purposes.