Adsorption characteristics of Zn(II) on thiol-functionalized spent grain

作者：Li Qing Zhu; Qin Wen Qing; Chai Li Yuan; Wang Qing Wei^*

来源：Chinese Journal of Nonferrous Metals, 2014, 24(4): 1076-1083.

• Adsorption capacities
• Adsorption characteristic
• Adsorption equilibrium isotherms
• Adsorption mechanism
• Adsorption performance
• Chemical adsorption
• Pseudo-second-order kinetic models
• Spent grains

The thiol-functionalized spent grain (TSG) was used to remove Zn(II) from wastewater. The effects of solution pH, reaction time and temperature and initial Zn(II) concentration on the adsorption were investigated. The adsorption mechanism was clarified by the adsorption equilibrium isotherm and adsorption kinetics model fitting combined with Fourier transform infrared spectroscopy (FTIR) analysis. The results show that the thiol-functionalized spent grain exhibits good adsorption performance over the wide pH range of 6-9. The maximum theoretical Zn(II) adsorption capacity of TSG calculated from Langmuir isotherm is 353.36 mg/g, which is higher than those of other modified lingocellulosic adsorbents reported (17.88-156 mg/g). In addition, the results of Zn(II) sorption kinetics by TSG indicate that the sorption process is fast and the equilibrium is established in 30 min. The sorption kinetics is well described by the pseudo-second order kinetic model. The calculated activation energy (Ea) implies that the adsorption of Zn(II) on TSG is a chemical adsorption. FTIR analysis demonstrates that the hydroxyl groups and sulphur atoms of thiol groups (S-H) of TSG complexing with the zinc ion leads to the adsorption.

• 出版日期2014
• 单位中南大学