naa a22 4500 510750389 CHVBK 20180411083102.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1007/s11270-013-1720-0 doi (NATIONALLICENCE)springer-10.1007/s11270-013-1720-0 Synthesis and Characterization of Thiolated Chitosan Beads for Removal of Cu(II) and Cd(II) from Wastewater [Elektronische Daten] [Soon Yong, Nanthi Bolan, Enzo Lombi, William Skinner] Removal of Cu(II) and Cd(II) from wastewater using porous chitosan beads is likely to be enhanced by the introduction of thiol groups (−SH). This is because, in accordance with the Hard Soft Acid Base concept, the soft Lewis base of -SH forms a strong bond with soft Lewis acid of Cd(II) or with borderline Lewis acids such as Cu(II). Possible formation of thiourea and disulfide crosslinks (−S-S-) may also confer increased bead stability in acidic solution. Thiolated chitosan beads (ETB) prepared and investigated in this study had a total sulfur content of 7.9%. The thiolation process slightly increased the Brunauer-Emmett-Teller surface area of the chitosan beads from 39.5 to 46.3m2/g. This ETB was categorised as a microporous material (pore aperture: 1.8nm) with multiple and uniform porous layers. Analysis by X-ray photoelectron spectroscopy indicated the presence of three sulfur species, S(−I), S(−II) and S(V) attributed to -S-S-, -SH and sulfonate (−SO3 −) groups. The Langmuir sorption capacity, q max, for Cd(II) was improved by 18 times by thiolation of chitosan. However, the q max for Cu(II) by ETB was seven times lower than that of pristine chitosan beads, possibly due to exhaustion of amine groups (−NH2). The batch sorption data was generally fitted well by a linearised Freundlich isotherm model and a Ho's pseudo-second-order kinetic model, indicating metal interaction with the heterogeneous surface of ETB and chemical adsorption as the possible rate-limiting step, respectively. The metal uptake has resulted in the oxidation of -SH to -SO3 − group in ETB, thereby decreasing the stability of metal-sulfide bonds as well as their metal uptake. Springer Science+Business Media Dordrecht, 2013 Chitosan nationallicence Heavy metal nationallicence Thiourea nationallicence Crosslink nationallicence Wastewater nationallicence Yong Soon Centre for Environmental Risk Assessment and Remediation, University of South Australia, 5095, Mawson Lakes, Australia aut Bolan Nanthi Centre for Environmental Risk Assessment and Remediation, University of South Australia, 5095, Mawson Lakes, Australia aut Lombi Enzo Centre for Environmental Risk Assessment and Remediation, University of South Australia, 5095, Mawson Lakes, Australia aut Skinner William Ian Wark Research Institute, University of South Australia, 5095, Mawson Lakes, Australia aut Water, Air, & Soil Pollution Springer Netherlands 224/12(2013-12-01), 1-12 0049-6979 224:12<1 2013 224 11270 https://doi.org/10.1007/s11270-013-1720-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-013-1720-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yong Soon Centre for Environmental Risk Assessment and Remediation, University of South Australia, 5095, Mawson Lakes, Australia aut NATIONALLICENCE 700 1- Bolan Nanthi Centre for Environmental Risk Assessment and Remediation, University of South Australia, 5095, Mawson Lakes, Australia aut NATIONALLICENCE 700 1- Lombi Enzo Centre for Environmental Risk Assessment and Remediation, University of South Australia, 5095, Mawson Lakes, Australia aut NATIONALLICENCE 700 1- Skinner William Ian Wark Research Institute, University of South Australia, 5095, Mawson Lakes, Australia aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/12(2013-12-01), 1-12 0049-6979 224:12<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer