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    The Removal of Textile Dyes with Cross-Linked Chitosan-Poly(acrylamide) Adsorbent Hydrogels
    (Taylor & Francis Inc, 2011) Ekici, Sema; Guntekin, Gamze; Saraydin, Dursun
    This study examined the behaviors and mechanisms of chitosan (CS)-poly(acrylamide) (PAAM) full interpenetrating polymeric network (IPN) hydrogels as an adsorbent to remove EY-4GL and S-Blue textile dyes from an aqueous solution. CS-PAAM IPN hydrogels were prepared by acrylamide monomer polymerization in the presence of a natural polymer, e. g., chitosan. N,N'-methylenebisacrylamide (MBAM) and glutaraldehyde (GLA) were selected to cross-link PAAM and CS chains and a full-IPN structure formed simultaneously. Kinetic swelling studies of CS-PAAM IPNs were carried out with deionized water and aqueous dye solutions. The experimental data clearly suggested that the swelling process obeys second-order kinetics. Network and diffusion parameters for CS-PAAM and PAAM hydrogels were calculated and it was observed that these IPN hydrogels have high cross-linking efficiencies in comparison to PAAM hydrogels. Adsorption of textile dyes onto hydrogels was studied by a batch adsorption technique at 23 degrees C and 40 degrees C, and it was seen that the higher temperature increased the dye adsorption onto the hydrogels. L type (Lan gmuir) adsorption isotherms, according to Giles classification system, were established at the end of adsorption experiments. The prepared IPN hydrogels show good ability to uptake textile dyes from wastewater.
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    Öğe
    Utilization of polyampholyte hydrogels for simultaneous removal of textile dyes from aqueous solutions
    (Taylor & Francis Inc, 2018) Ekici, Sema; Guntekin, Gamze
    The study aimed to create hydrogel structures with greater functionality, otherwise known as polyampholytes (PAHs), and to use these in simultaneous removal studies for remazol-type dyes found in environmental waste waters. Adsorption studies were accomplished at 20 degrees C and 35 degrees C, indicated that adsorption process was exothermic in nature. The Q(m) values for the PAH-dye systems were in the interval 111-122mg dye/g PAH with Ads% from 94% to 98%. The ability of PAH hydrogels to adsorb two different species of dye molecules at the same time is an advantage of PAH adsorbents compared to other hydrogel adsorbents prepared in this area.