Correlating metal ionic characteristics with biosorption capacity using QSAR model

Abstract

The relationship between metal ionic characteristics and the maximum biosorption capacity ( q max) was established using QSAR model based on the classification of metal ions (soft, hard and borderline ions). Ten kinds of metal ions (Ag +, Cs +, Zn 2+, Pb 2+, N i2+ , Cu 2+, Co 2+, Sr 2+, Cd 2+, Cr 3+) were selected and the waste biomass of Saccharomyces cerevisiae obtained from a local brewery was used as biosorbent. Eighteen parameters of physiochemical characteristics of metal ions were selected and correlated with q max. Classification of metal ions could improve the QSAR models and different characteristics were significant in correlating with q max, such as polarizing power Z 2/ r or the first hydrolysis constant |log K OH| or ionization potential IP. X m 2 r seemed to be suitable for metal ions including soft ions, and Z 2/ r, |log K OH| and IP suitable for only soft ions or metal ions excluding soft ions. It provided a new way to predict the biosorptive capacity of metal ions.