Biosorption behavior and mechanism of heavy metals by the fruiting body of jelly fungus (Auricularia polytricha) from aqueous solutions

Abstract

The aim of this study was to investigate the bio-sorption characteristics of Cd2+, Cu2+, and Pb2+ by the fruiting body of jelly fungus Auricularia polytricha. Batch experiments were conducted to characterize the kinetics, equilibrium, and mechanisms of the biosorption process. Optimum values of pH 5, biomass dosage 4 gL-1, and contact time 60 min provided maximum biosorption capacities of A. polytricha for Cd 2+, Cu2+, and Pb2+ of 63.3, 73.7, and 221 mg g-1, respectively. The maximum desorption was achieved using 0.05 mol L-1 HNO3 as an elute. The fruiting body was reusable at least for six cycles of operations. The pseudo-second-order model was the best to describe the biosorption processes among the three kinetic models tested. Freundlich and Dubinin-Radushkevich models fitted the equilibrium data well, indicating a heterogeneous biosorbent surface and the favorable chemisorption nature of the bio-sorption process. A Fourier transform infrared spectroscopy analysis indicated that carboxyl, amine/hydroxyl, amino, phosphoryl, and C-N-C were the main functional groups to affect the biosorption process. Synergistic ion exchange and surface complexation were the dominant mechanisms in the biosorption process. The present work revealed the potential of jelly fungus (fruiting body of A. polytricha) to remove toxic heavy metals from contaminated water. © Springer-Verlag 2012.