Comparison between the removal of Reactive Black 5 from aqueous solutions by 3-amino-1,2,4 triazole,5-thiol and melamine grafted chitosan prepared through four different routes

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