Removal of Ag(I) from Aqueous Solution by Japanese Natural Clinoptilolite  

作　　者：Takaaki Wajima Takaaki Wajima(Department of Urban Environment Systems, Graduate School of Engineering, Chiba University, Chiba, Japan)

机构地区：[1]Department of Urban Environment Systems, Graduate School of Engineering, Chiba University, Chiba, Japan

出　　处：《Advances in Chemical Engineering and Science》2016年第4期470-487,共18页化学工程与科学期刊（英文）

摘　　要：The present study examined the adsorption of silver ion in aqueous solution onto natural clinoptilolite zeolite from Futatsui Mine, Akita Prefecture, Japan. The effects of various parameters, i.e., solution pH, adsorbent dosage, adsorption time, silver ion solution concentration, and temperature, on silver ion adsorption process onto clinoptilolite were examined. Additionally, the thermodynamics of the silver ion adsorption process was investigated. The optimum pH for silver adsorption was determined to be around 4.0. The adsorption process could be well described by the Langmuir isotherm model. The calculated maximum adsorption capacity was 0.64 mmol/g. Adsorption kinetics studies were also conducted. The results showed that the adsorption process preferentially followed the pseudo-second-order kinetics model over the pseudo-first-order model. Furthermore, with decreasing aqueous solution temperatures, the adsorption kinetics became slower and the amount of silver ion adsorbed increased. The thermodynamic values, ΔG⁰, ΔH⁰, and ΔS⁰, indicated that adsorption was an exo-thermic and spontaneous process.The present study examined the adsorption of silver ion in aqueous solution onto natural clinoptilolite zeolite from Futatsui Mine, Akita Prefecture, Japan. The effects of various parameters, i.e., solution pH, adsorbent dosage, adsorption time, silver ion solution concentration, and temperature, on silver ion adsorption process onto clinoptilolite were examined. Additionally, the thermodynamics of the silver ion adsorption process was investigated. The optimum pH for silver adsorption was determined to be around 4.0. The adsorption process could be well described by the Langmuir isotherm model. The calculated maximum adsorption capacity was 0.64 mmol/g. Adsorption kinetics studies were also conducted. The results showed that the adsorption process preferentially followed the pseudo-second-order kinetics model over the pseudo-first-order model. Furthermore, with decreasing aqueous solution temperatures, the adsorption kinetics became slower and the amount of silver ion adsorbed increased. The thermodynamic values, ΔG⁰, ΔH⁰, and ΔS⁰, indicated that adsorption was an exo-thermic and spontaneous process.

关 键 词：CLINOPTILOLITE Ag(I) Removal ADSORPTION Natural Zeolite 

分 类 号：O64[理学—物理化学]