Enhanced removal of Hg(II) from acidic aqueous solution using thiol-functionalized biomass

摘要

Spent grain, the low-cost and abundant biomass produced in the brewing industry, wasnfunctionalized with thiol groups to be used as an adsorbent for Hg(II) removal from acidicnaqueous solution. The adsorbents were characterized by the energy-dispersive X-ray analysisn(EDAX) and Fourier transform infrared (FTIR) spectroscopy. Optimum pH for Hg(II) adsorptionnonto the thiol-functionalized spent grain (TFSG) was 2.0. The equilibrium and kinetics of thenadsorption of Hg(II) onto TFSG from acidic aqueous solution were investigated. From the Langmuirnisotherm model the maximum adsorption capacity of TFSG for Hg(II) was found to ben221.73mg g21n, which was higher than that of most various adsorbents reported in literature.nMoreover, the adsorption of Hg(II) onto TFSG followed pseudo-second-order kinetic model.