Equilibrium, kinetic and mechanism studies on the biosorption of Cu2+ and Ni2+ by sulfur-modified bamboo powder

Two biosorbents were prepared using bamboo powder modified with mercaptoacetic acid and carbon disulfide, which exhibits strong adsorption properties for Cu2+ and Ni2+. The obtained materials were characterized by FTIR. Maximum adsorption for both metals was found to occur around pH 5.0–6.5. The kinetic data followed the pseudo-second-order model. The maximum adsorption capacities of Cu2+ and Ni2+ on mercaptoacetic acid modified bamboo powder determined from Langmuir isotherm were 103.97mg g−1 and 61.35mg g−1, respectively. While on carbon disulfide modified bamboo powder were 128.21mg g−1 and 56.82mg g−1, respectively. The adsorption mechanism analysis revealed that the most possible adsorption mode of Cu2+ was coordination, and Ni2+ was ion exchange. The obtained adsorbents could effectively remove Cu2+ and Ni2+ from industrial electroplating wastewater and could be used repeatedly for more than five cycles.