Extraction of Heavy Metals from Aqueous Solutions using Chitosan/Montmorillonite Hybrid Hydrogels

Hydrogels based on chitosan, a biodegradable and abundant natural polymer, have received significant interest in various applications, including the removal of heavy metals from aqueous solutions. Novel chitosan (CTS)/ montmorillonite (MMT) hybrid hydrogels have been successfully developed by freeze-drying technique. The morphology of the hydrogels is observed to be porous and the existence of reactive ligands for chelation is confirmed, The stability of the hydrogels is improved by introducing polyvinyl alcohol (PVA) and increasing the cross-linking agent. Interestingly, the increment of MMT content also enhances the mechanical strength of the hydrogels. Adsorption study is performed with Cu(II) to evaluate the effects of pH and Cu(II) initial concentration. The maximum adsorption capacities at pH 3, 7 and 10 are 286, 282 and 179 mg/g, respectively, for the hybrid hydrogels with high content of chitosan. Langmuir isotherm provides the best fit for Cu(II) adsorption. Finally, the selectivity of CTS/MMT hybrid hydrogels toward various metal ions was determined. The order of selectivity is Cu(II)>Cr(III)˜Co(II)> Ni(II)>Zn(II).

Name thesis:degree_name

Master of Sciences

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Chemical Engineering

Grantor dc:publisher

Case Western Reserve University School of Graduate Studies

Year dc:date

2013

Author dc:creator

• Mahaweero, Thanatdej

Contributors dc:contributor

• Qutubuddin, Syed

• Chemical Engineering

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=case1365160267

OAI identifier oai:identifier

oai:etd.ohiolink.edu:case1365160267