Competitive sorption efficiency studies of Cd(II), Cu(II) and Pb(II) by powdered mycelium of Cloud Ear Fungus Auricularia polytricha

Abstract

This study provides a theoretical basis for use of the Cloud Ear Fungus Auricularia polytricha powdered mycelium as a sorbent for removal of heavy metals from aqueous solution. The sorption efficiency of Cd(II) alone was greater than that of Pb(II) or Cu(II), while of Pb(II) was greater than that of Cu(II). Pb(II) highly competed with Cd(II) for the binding sites during sorption process and its binding efficiency was higher than Cd(II). A competition from Cu(II), present in small concentration (≤5 mg/L) in solution, promoted the sorption efficiency of Pb(II) but affected sorption negatively, when both solutes occurred at an equal concentration of 10 mg/L. Small concentration (≤5 mg/L) of Cu(II) decreased sorption rate of Cd(II), while a further increase of its concentration to 10 and to 30 mg/L, promoted the sorption efficiency of Cd(II). An influence of Cd(II) on the sorption efficiency of Cu(II) was not so obvious as that of Cu(II) on Cd(II) sorption. The results showed that competition between Cd(II), Cu(II) and Pb(II) for the binding sites onto the cell wall surfaces of the A. polytricha powdered mycelia biomass can be affected by two factors – one was physical and chemical features (ionic radius) of these metal cations, while another was the thiol (−SH) functional groups of the sorbent.

Keywords:

• Bio-sorption
• fungi
• heavy metals
• mushrooms
• wastewater treatment

Acknowledgments

This study was supported by the National Natural Science Foundation of China (40871111).