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ELwakeel K.Z.,Port Said University | El-Kousy S.,Menoufia University | El-Shorbagy H.G.,Al Menofia Water and Wastewater Company | El-Ghaffar M.A.A.,National Research Center of Egypt
Journal of Environmental Chemical Engineering | Year: 2016

Chitosan was modified through four different modification routes. First, epichlorohydrine cross-linked Chitosan was grafted with 3-Amino-1,2,4 triazole,5-thiol and melamine to produce RI and RII, respectively. Second, glutaraldehyde cross-linked chitosan was chemically modified using ammonium hydroxide then grafted with 3-Amino-1,2,4 triazole,5-thiol and melamine to produce RIII and RIV, respectively. The prepared polymers were characterized via FTIR, TGA, elemental analysis, water regain and surface area. RIII and RIV shows higher thermal stability, bigger surface area, and lower water regain, than RI and RII. Removal of Reactive Black 5 (RB5) anions from their aqueous solutions were studied using the modified chitosan adsorbents under various parameters such as pH, agitation time, and temperature. The maximum adsorption capacities are 0.492, 0.330, 0.622 and 0.698 mmol g-1 for RI, RII, RIII, and RIV, respectively, at pH 3 and 25 °C. The nature of interaction of RB5 with the adsorbents was identified. Uptake kinetics and adsorption isotherms were modeled using conventional and simple equations: best results were respectively obtained with the pseudo-second order rate equation and the Langmuir equation. The thermodynamic parameters have been calculated: the adsorption is endothermic, spontaneous and contributes to increase the entropy (randomness) of the system. RI and RII gives higher desorption yield than RIII and RIV, this probably due to the presence of the quaternary ammonium moiety in the last two sorbents. © 2015 Elsevier Ltd. All rights reserved.


Elwakeel K.Z.,Port Said University | Abd El-Ghaffar M.A.,National Research Center of Egypt | El-Kousy S.M.,Menoufia University | El-Shorbagy H.G.,Al Menofia Water and Wastewater Company
Journal of Dispersion Science and Technology | Year: 2013

Chitosan was cross-linked using epichlorohydrine to form chitosan gel. The resins obtained were chemically modified through the reaction with to 1,1,1,3,3,3 hexafloro,2-bis (3-amino,2-hydroxyphenyl) propane to produce resin (RI), 3-amino-1,2,4 triazole,5-thiol to produce resin (RII), and melamine to produce resin (RIII). The uptake of Reactive Black 5 (RB5) from aqueous media by the obtained resins was studied using batch method. Various parameters such as pH, agitation time, RB5 concentration and temperature were studied. The resins showed high affinity for the adsorption of RB5 where uptake values of 0.63, 0.45, and 0.33 mmol/g were reported for resins RI, RII, and RIII, respectively at 25°C. Both kinetics and thermodynamic parameters of the process were estimated. These data indicated an endothermic spontaneous adsorption process and kinetically followed the pseudo-second order model, Fickian diffusion low and Elovich equation. Desorption of RB5 from the surface of the prepared resins was efficiently done using sodium hydroxide. © 2013 Copyright Taylor and Francis Group, LLC.


Elwakeel K.Z.,Port Said University | Abd El-Ghaffar M.A.,National Research Center of Egypt | El-kousy S.M.,Menoufia University | El-Shorbagy H.G.,Al Menofia Water and Wastewater Company
Chemical Engineering Journal | Year: 2012

Chitosan/gluteraldehyde resin was chemically modified using ammonium hydroxide to produce (RI) resin, which was additionally semi cross-linked with epichlorohydrine through hydroxyl group of chitosan. The obtained resin was modified with 3-Amino-1,2,4 triazole,5-thiol to produce resin (RII)/or melamine to produce resin (RIII). The uptake of modified chitosan resins toward Brilliant Blue R250 (BBR250) from aqueous media was studied using batch method. Various parameters such as pH, agitation time and temperature had been studied. The resins showed high affinity for the adsorption of BBR250 from aqueous media where uptake values of 0.97, 0.79 and 2.505. mmol/g were reported for resins RI, RII and RIII at 25 °C, respectively. Both kinetics and thermodynamic parameters of the process were estimated. These data indicated an endothermic spontaneous adsorption process and kinetically followed the pseudo-second order model, Fickian diffusion low and Elovich model. Desorption of BBR250 from the prepared resins was efficiently done using sodium hydroxide. © 2012 Elsevier B.V.

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