A QICAR model for quantifying connection between metal ionic character and biosorption capacity of Pleurotus eryngii

摘要

Quantitative ion character-activity relationship (QICAR) was used for quantifying connection between metal ionic characteristics with maximum biosorption capacity (q_(max)). q_(max) of Pleurotus eryngii was determined by Langmuir isotherm decreasing in the order of: Pb~(2+)＞Cr~(3+)＞Cu~(2+)＞Zn~(2+)＞Cd~(2+)＞Ni~(2+)＞K~+. In batch studies, Minimum Run Res V Design was used to determine the most significant medium factors. It was found that pH, biomass loading, and contact time manifest stronger influence on biosorption of Pb~(2+) and Cd~(2+). In the 22 physiochemical characteristics of metal ions, Covalent Index X_m~2r was correlated best with q_(max) for all metal ions tested (R~2 = 0.69). Classifying metal ions appropriately could improve models and more ionic properties could be significantly correlated with q_(max). It turned out that the best fitting parameter for divalent metal ions was X_m~2 (R~2 = 0.93) and for transition metal ions was | log K_(OH) | (R~2 = 0.90). Moreover, two-variable model had greater ability to improve the fitting result (R~2 = 0.99).