Removal of Cd2+ ions from aqueous solution using cassava starch–based superabsorbent polymers |
| |
Authors: | Wenbo Bai Liren Fan Yang Zhou Yin Zhang Jiyan Shi Guohua Lv Yongfeng Wu Qi Liu Jiqing Song |
| |
Affiliation: | 1. Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China;2. Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan, People's Republic of China;3. China Ground Golden Shield Environment Technology Co. Ltd, Wuhan, People's Republic of China |
| |
Abstract: | A comprehensive feasibility study on the adsorption of Cd2+ ions by cassava starch–based superabsorbent polymers (CST‐SAPs) as the biosorbent was investigated as a function of adsorbent dosage, pH, initial concentration, contact time, and temperature. An orthogonal experiment and range analysis were applied to optimize the adsorption conditions. Adsorbent dosage and initial concentration were the most sensitive variables for adsorption capacity. The maximum adsorption value of Cd2+ ions was determined as 347.46 mg/g at pH 6.0, initial concentration of 200 mg/L, and contact temperature and time of 323 K and 6 h, respectively, with 0.1 g adsorbent dosage. The equilibrium data were well described by a Langmuir model, and the adsorption process was well fitted by pseudo‐second‐order kinetics. The Fourier transform infrared spectroscopy (FTIR) data confirmed that acrylic acid and acrylic amide grafted onto the cassava starch. The X‐ray diffraction and FTIR results for the Cd2+‐absorbed CST‐SAP (CST‐SAP‐Cd2+) samples showed that the CST‐SAP could effectively adsorb Cd2+ ions and that the characteristic groups were translocated by chelation. The scanning electron microscopy results for the CST‐SAP revealed that the surface of the polymer was rough, and the layered structure that was full of folds caused an enhanced specific surface; such conditions were beneficial to Cd2+ ion adsorption. It was concluded that the CST‐SAP was an excellent adsorbent for Cd2+ ion removal from aqueous solution. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44758. |
| |
Keywords: | adsorption biosynthesis of polymers crosslinking grafting kinetics |
|
|