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Abstract
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In the water environment, heavy metals are one of the principal contaminants. Before releasing the waste stream into the ecosystem, industries must lower the content of these metals below the governmentset standard concentration.[1] According to the US Environmental Protection Agency (USEPA), the maximum allowable concentration of Pb(II) is 6 μg/L inground or surface water.[2] In this study, environmentally friendly magnetic chitosan- Zeolite based flocculants was synthesized for efficient adsorption of Pb(II) and Cr(VI). Chemical cross-linking of the linear chains of chitosan can be achieved by cross-linking agents such as glutaraldehyde (GA) and epichlorohydrin to develop a triple-network structure with improved mechanical properties and improved absorption capacity. Given the large number of amino and hydroxyl groups on the surface of chitosan molecules, these groups contain lone pairs of electrons that can chelate with Cr(VI), Pb(II), and other heavy metal ions through coordination. Moreover, the developed chitosan- Zeolite based composite exhibited good potential for re-use after five cycles of regeneration, thus, indicating their potential as cost-effective adsorbents for removal of Pb(II) ions from both drinking and wastewater. The Langmuir-maximum adsorption capacities of Pb(II) ions for all the analysed chitosan- Zeolite based composites and beads was found to range from 42.48 ± 4.22 to 94.60 ± 5.63 mg/g.
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