Biosorption of Ni (II) on industrial anaerobic sludge was investigated at 308.1 K and 7.5 pH in a batch reactor. The effective metal sorption capacity was of 10.25 mgNi/gTSS. Equilibrium data were fitted using Langmuir and Freundlinch models and the results compared by non-linear regression. A better agreement with experimental data was shown by Freundlich isotherm. Effects on methane production were also studied with the purpose of investigate if the biosorption process could occur without any variation in the ability of the anaerobic sludge to produce biogas. The results reveal that methane production rapidly drops for low metal concentration and that it can be partially recovered with further metal addition.
