Succinate-bonded pullulan: An efficient and reusable super-sorbent for cadmium-uptake from spiked high-hardness groundwater |
| |
Authors: | Azhar Abbas Muhammad Ajaz Hussain Muhammad Amin Muhammad Sher Muhammad Nawaz Tahir Wolfgang Tremel |
| |
Institution: | 1 Department of Chemistry, University of Sargodha, Sargodha 40100, Pakistan;2 Institute of Inorganic and Analytical Chemistry, Johannes Guttenberg University, Duesbergweg 10-14, 55128 Mainz, Germany |
| |
Abstract: | Chemically modified pullulan was evaluated for its sorption efficiency and selectivity to remove cadmium (Cd) from spiked high-hardness groundwater (GW). Pullulan esterified with succinic anhydride using dimethylaminopyridine showed a fairly high degree of substitution value as confirmed by 1H NMR spectroscopy. Pullulan succinate (Pull-Suc) was converted into the sodium salt (Pull-Suc-Na). The effect of contact time (5–200 min) and pH (2–8) on Cd-uptake by the sorbent (Pull-Suc-Na) was investigated. The sorbent showed more than 90% Cd-removal in first 15 min from distilled water (DW) and GW solution, respectively. Comparison of Pull-Suc-Na with other polysaccharidal sorbents suggested its high efficiency (DW 476.2 mg/g and GW 454.5 mg/g) and selectivity for the removal of Cd by an ion exchange mechanism, which is further supported by the negative Gibbs free energy values calculated from Langmuir isotherms. A Langmuir isotherm kinetic model provided the best fit for the sorption of Cd using Pull-Suc-Na. The sorbent showed a negligible decrease in Cd-uptake over three regeneration cycles. The thermal stability testing of the sorbents indicated that Pull-Suc-Na (sorbent) is more stable than Pull-Suc. |
| |
Keywords: | Adsorption Cadmium Modified pullulan Succinylation Thermal stability |
本文献已被 CNKI 万方数据 等数据库收录! |
| 点击此处可从《环境科学学报(英文版)》浏览原始摘要信息 |
| 点击此处可从《环境科学学报(英文版)》下载免费的PDF全文 |