标题：Preparation and characterization of beta-FeOOH-coated sand and its adsorption of Cr(VI) from aqueous solutions
作者：Xu, Chunhua; Cheng, Dandan; Gao, Baoyu; Yin, Zhilei; Yue, Qinyan; Zhao, Xian
作者机构：[Xu Chunhua] School of Environmental Science and Engineering,Shandong University, Shandong Key Laboratory of Water Pollution Control and Resource Reus 更多
通讯作者地址：[Gao, BY]Shandong Univ, Sch Environm Sci & Engn, Shandong Key Lab Water Pollut Control & Resource, Jinan 250100, Peoples R China.
摘要：Batch adsorption experiments were conducted to explore the adsorption of Cr(Ⅵ) in aqueous solutions by β-FeOOH-coated sand.We investigated the key factors which affected the adsorption process such as adsorbent dosage,initial pH,initial Cr(Ⅵ) ion concentration,contact time and temperature.The uptake of Cr(Ⅵ) was very rapid and 44.3％,51.6％,58.9％ of the adsorption happened during the first 180minutes at 293K,303K and 313K,respectively.The pseudo-second-order rate equation successfully described the adsorption kinetics.To study the adsorption isotherm,two equilibrium models,the Langmuir and Freundlich isotherms,were adopted.At 293K,303K and 313K,the adsorption capacities obtained from the Langmuir isotherm were 0.060,0.070 and 0.076 mg Cr(Ⅵ) per gram of the adsorbent,respectively.Thermodynamic parameters such as the change of energy,enthalpy and entropy were calculated using the equilibrium constants.The negative value of AG0 and the positive value of △H0 showed that the adsorption of Cr(Ⅵ) in aqueous solutions by β-FeOOH-coated sand was spontaneous,endothermic and occurred by physisorption.