Kinetics and isotherm study of reactive red 120 dye adsorbed onto Chitosan modified zero-valent iron nanoparticle (CS-nZVI).

Because of easy dyeing operations and high durability throughout the washing process, azo dyes of a reactive nature are widely employed in textile coloring methods. About twenty to forty percent of these colors stay in the effluents. As a result of their reactive, toxic, and stable nature, discharges of such effluent into receiving waterways might be dangerous to exposed species. Azo dyes are the most common cause of mutation and cancer among xenobiotic contaminants. The removal of these pigments, as well as the clean-up of linked polluted areas, remains a global challenge. The sorption of reactive dyes on diverse adsorbing agents like bacteria, fungus, algae, water plants, and chitosan has been well-researched, etc. Various adsorbing agents like Lentinus sajor-caju, Spirogyra majuscule, pistachio husk, Hydrilla verticillate, chitosan, palm oil industry waste, clay were utilized to remove Reactive Red (RR) 120. This study investigates the synthesis of Chitosan-enhanced Nano Zero-Valent Iron (CS-nZVI), the adsorption of RR dye by the synthesized material as well as its kinetic and isothermal studies. The adsorptive capability was calculated to be 3.017481mg/g. Kinetic model – pseudo-1st, pseudo-2nd, and elovich models, isotherm models— Langmuir, Freundlich, Jovanovic, Sips, Vieth-Sladek, Khan, Radke-Prausnitz and Unilan, were utilized as well as non-linear regression fittings. Discriminatory analyses of statistical data centered on RMSE (root-mean-square error), adjR2 (adjusted coefficient of determination), AF (accuracy factor), AICc (Akaike Information Criterion corrected) BF (bias factor), were used in finding the superior fit model. The best kinetic models were both pseudo-1st and pseudo 2nd order and the best isotherm model was Vieth-Sladek. The results obtained suggest reliable isothermal and kinetic behavior that will allow the fitting of several models when the zero-valent iron nanoparticle is used in the adsorption of other anionic azo dyes. [ABSTRACT FROM AUTHOR]