title: Efficient removal of cesium from aqueous solution with vermiculite of enhanced adsorption property through surface modification by ethylamine.
abstract: Ethylamine modified vermiculite (Ethyl-VER) with high specific surface area and excellent pore structure was prepared to remove cesium from aqueous solution. The physic-chemical properties of the pristine and modified vermiculite were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), specific surface area (BET) and scanning electron microscopy/energy disperse spectroscopy (SEM/EDS). The corroding effect of ethylamine increased the specific surface area of vermiculite from 4.35 to 15.59 m(2) g(-1), and the average pore diameter decreased from 6.8 to 5.34 nm. Batch adsorption experiments were conducted as a function of pH, initial Cs(+) concentration, contact time, coexisting cations (K(+), Na(+), Ca(2+)) and low-molecular-weight organic acids (acetic acid, oxalic acid, citric acid) to illustrate the adsorption behavior. The study found that the adsorption capacity of cesium in aqueous solution was improved from 56.92 to 78.17 mg g(-1) after modification. The formation of micropores and mesopores and the increased surface area played a critical role in the enhancement of cesium adsorption. Kinetic experiments indicated that the adsorption process can be simulated well with a pseudo-second-order model. The presence of cations or low-molecular-weight organic acids inhibited cesium adsorption in different degrees. On the basis of our results, Ethyl-VER with good surface characteristics and high adsorption capacity is a suitable adsorbent for cesium removal from aqueous solution.
authors.affiliation: College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors.forename: Hang
authors.initials: H
authors.lastname: Long
authors.affiliation: College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, PR China. Electronic address: pppxwu@scut.edu.cn.
authors.forename: Pingxiao
authors.initials: P
authors.lastname: Wu
authors.affiliation: College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.affiliation: College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors.forename: Zhujian
authors.initials: Z
authors.lastname: Huang
authors.affiliation: College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, PR China.
authors.forename: Nengwu
authors.initials: N
authors.lastname: Zhu
authors.affiliation: College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China.
authors.forename: Zhixian
authors.initials: Z
authors.lastname: Hu
keywords: Adsorption; Cesium; Ethylamine; Organic acids; Surface modification; Vermiculite