Biosorption Mechanism of Zn2+ and Cd2+ by a Rhodotorula mucilaginosa

WT6-5, a Rhodotorula sp. isolated from a Tailings Reservoir soil in Liaoning province, might have ability to adsorb heavy metals. Its biosorption ability and mechanism for zinc and cadmium were studied, and the results showed that the removal efficiency of zinc and cadmium were up to 78.0% and 100% separately, with the. wet biomass of 18mg/mL and the conditions of Zn2+ 10mg/L and Cd2+ 1mg/L. In order to identify the main sorption characteristics of WT6-5, biosorption time, wet biomass and pH values were measured. The main biosorption functional groups including hydroxide, acylamide, carboxyl, C-N, carbonyl and sulfur carbonyl were analyzed by IR spectroscopy; moreover, zinc and cadmium ions absorbed by WT6-5 distributed in cell wall after destroying capsule were observed with SEM. The results suggested that WT6-5 was a valuable biosorbent for treating the heavy metal pollution.