Abstract
The purpose of this research is to investigate the removal of Hexavalent-Chromium Cr(VI) ion using activated carbons prepared from the barks of Pterocarpus Marsupium Roxb. by phosphoric acid, specifically Pterocarpus Marsupium Bark Carbon, Acid modified Pterocarpus Marsupium Bark Carbon, and Base modified Pterocarpus Marsupium Bark Carbon. Batch adsorption studies are performed by varying factors such as solution pH, adsorbent dosage, contact time, starting concentration, and temperature. Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich isotherm equations were used to process equilibrium data. Isotherm constant values were found and their relevance was explained. The adsorption of Cr(VI) ions onto PBC, APBC, and BPBC was compared. The data collected from the influence of contact time for varying beginning concentrations were processed using the kinetic equations of Lagergren, ΔHo, and Webber Morris. The expected adsorption capacity and rate constants were determined. The adsorption capacities predicted were compared to experimental adsorption capacities. The statistical method Mean Summation of Error Squares (MSSE) was used to find the best-fitting model. The thermodynamic quantities ΔH°, ΔS°, and ΔG° were calculated using equilibrium data collected at various temperatures. The conclusions drawn from these values were addressed. The ability of adsorbents loaded with Cr (VI) ions to regenerate in acidic, alkaline, and neutral mediums was examined. To understand the adsorbate-adsorbent interactions, the FTIR spectra and EDAX of adsorbents were examined before and after sorption of Cr (VI) ions.