Paper Title
Removal of Reactive Black 5 (RB5) from Aqueous Solutionby Cross-Linked Magnetic Biosorbent

The aim of this study is investigate to the equilibrium and kinetics of adsorption of anionic reactive dye in acid solutions. Chitosan was cross-linked using glutaraldehyde in the presence of magnetite.The adsorption capacity of Reactive Black 5(RB5)oncross-linked glutaraldehyde magnetic chitosan nanoparticles (GMCNs) was studied. During the studies, various essential factors influencing the adsorption, like adsorbate concentration and contact time have been monitored. The effect of pH value of solution on adsorption capacity was also investigated. The equilibrium was achieved within 17 h for the RB5 at pH 4, and the maximum sorption capacity calculated by applying the Langmuir equation to dye adsorption isotherm was357.1mg/g (C0 = 0.11-0.20 mM) for the RB5 at pH 4, 30 °C. The effect of initial dye concentration on the dynamical behaviors of the adsorption was measured. To determine the adsorption rates, the nonlinear first-order and second-order models were used. The second-order kinetic model fits well with the dynamical adsorption behavior of the RB5. The nanoparticles for the adsorption of the dye were regenerated efficiently through the alkaline solution and were then reused 10 times for dye removal. Keywords-Cross-linked magnetic chitosan, Reactive black 5, Adsorption kinetics, Adsorption isotherms, Reusability