Adsorption characteristics of nickel on Bacillus cereus M-16(1) biomass have been studied under varied environmental conditions to explore the potentiality of the biomass for controlling water pollution due to nickel. The optimized parameters for adsorption process are as follows: pH: 7.0, temperature: 40 degrees C, biomass dosage: 2 g L-1. The process is best fitted to Redlich-Peterson isotherm model and follows pseudo-second order rate model. The combination of zeta potential measurement, SEM - EDXA, XRD, XPS, FTIR, TGA, and DSC studies allow a more comprehensive characterization of biomass to understand the mechanisms involved in nickel (II) adsorption in aqueous system.