The use of magnetic multiwalled carbon nanotubes functionalized with chitosan for nitrate removal from wastewater

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بشارات, إيناس إبراهيم محمود
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An-Najah National University
This study aims to synthesis magnetic multiwalled carbon nanotubes functionalized with chitosan, and used for removal of nitrate from wastewater. The resulting adsorbent characterized by TEM, ATR, XRD, TGA and Raman analysis. This porous material showed a very good thermal and chemical stability and hence it can be used as perfect adsorbent to uptake nitrate ions from wastewater. The concentration of the nitrate in the filtrate was determined using UV-visible Spectrophotometer. The results showed that the resulting product has high adsorption efficiency. Also, it showed strong complexation properties with nitrate ions. In order to investigate the adsorption efficiency for the adsorption of nitrate onto magnetic multiwalled carbon nanotubes functionalized with chitosan the effect of solution conditions on each adsorption process were studied. These conditions involve the effect of contact time, pH value, temperature, adsorbent dose and the initial concentration of adsorbate. The best equilibrium isotherm model for each adsorption process was investigated according to the value of the correlation coefficient of Langmuir and Freundlich isotherm adsorption models. The kinetics of adsorption were also investigated using pseudo first-order, pseudo second- order and intra-particle diffusion kinetic models. In addition, Van’t Hoff plot for the adsorption was investigated in order to determine the values of enthalpy change and entropy change, and hence determining if the adsorption process is spontaneous or not, and if it is exothermic or endothermic one. The results showed that the adsorption followed Frenndlich isotherm and the mechanism of the reaction followed pseudo first-order kinetic adsorption model. The thermodynamic parameters of the adsorption proved that this process is endothermic (ΔH > 0) and spontaneous (ΔS > 0). The synthesized adsorbent was also regenerated, and the percentage removal before and after adsorbent recovery is determined.