Batch adsorption of Fe3+ ions from aqueous solutions using activated carbon derived from Horse Chestnut Shells found in Northwestern Himalayas: Equilibrium, kinetic and thermodynamic studies

This research paper analyses the adsorbent properties of a unique biomass i.e. horse chestnut shell (Aesculus hippocastanum L) activated carbon synthesized by chemical activation of KOH produced under optimized carbonization conditions for Fe3+. Research was done to look into the characteristics of the made activated carbon and its systematic effects of process parameters. Characterizations like SEM, BET, FTIR, XRD, TGA, EDX, proximate and ultimate analysis, calorific value was performed. Also effect of process parameters like initial Fe3+ ion content, contact time, dosage and temperature of system was studied for mechanism of adsorption at pH (6) of Fe3+ in an aqueous solution. Data on equilibrium and kinetic isotherms from experiments were examined, for kinetics pseudo 1st order reaction, pseudo 2nd order reaction and intraparticle diffusion has been utilised. System was fairly fitted by pseudo-2nd-order reaction. Adsorption isotherms such as Halsey, Harkin Jura, Temkin, Freundlich, and Langmuir and Dubinin Radushkevich were used and Langmuir adsorption isotherm turned out best suitable match as R-2 value was found out to be 0.99. The maximum Fe3+ adsorbing ability of the HCAC4 was 138.88 mg/g at 25 degrees C. Thermodynamical evaluation concluded the process to be spontaneous and heat-releasing.