Biosorption of Toxic Transition Metals and Radionuclides from Aqueous Solutions by Agro-Industrial Byproducts

AbstractAn investigation was conducted on different agro-industrial byproducts to evaluate their potentiality for simultaneous removal of Pb2+, Zn2+, Cu2+, Ni2+, Cd2+, Cr3+, UO22+, and Th4+ from aqueous solutions. All experiments were performed in batch mode at ambient temperature. According to the results obtained from pH, rice bran was selected as the most effective biosorbent. In a single step, more than 91% of studied cations (except Ni2+ and Cr3+) were simultaneously removed by rice bran from aqueous solution with RSD less than 2.19%. Also, the sorption process was very quick, and sorption equilibrium was achieved in about 10 min for all studied cations. The obtained results from all experiments showed that sorption behavior of Th4+ onto rice bran was different from other heavy metals, so that its sorption efficiency (>95%) did not have considerable change with varying pH from 3 to −0.6. The electrostatic complexation mechanism was recognized between hard-functional groups of rice bran biomass and Th...