Enhanced and selective adsorption of Pb2+ and Cu2+ by EDTAD-modified biomass of baker’s yeast

Abstract Enhanced and selective removal of Pb 2+ and Cu 2+ in the presence of high concentration of K + , Na + , Ca 2+ and Mg 2+ were achieved by adsorption on biomass of baker’s yeast modified with ethylenediaminetetraacetic dianhydride (EDTAD). The modified biomass was found to have high adsorption capacities and fast rates for Pb 2+ and Cu 2+ , and it also displayed consistently high levels of metal uptake over the pH range from 2.7 to 6.0. From Langmuir isotherm, the adsorption capacities for Pb 2+ and Cu 2+ were found to be 192.3 and 65.0 mg g −1 , respectively, which are about 10 and 14 times higher than that of the unmodified biomass. Competitive biosorption experiments showed that the co-ions of K + , Na + , Ca 2+ and Mg 2+ had little effects on the uptake of Pb 2+ and Cu 2+ even at the concentration of 1.0 mol L −1 . The adsorbed Pb 2+ and Cu 2+ on the modified biomass could be effectively desorbed in an EDTA solution, and the regenerated biomass could be reused repeatedly with little loss of the adsorption capacity.