Spectral Interpretation of Dye Adsorption on Activated Carbons
Dr. K. Venkata Krishna
Associate Professor of Chemistry, Government Degree College for Women (A), Nalgonda.
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http://doi.org/10.37648/ijps.v18i01.020
Abstract
Activated carbons can remove dissolved dyes through interactions governed by accessible porosity, surface chemistry and solution conditions. This review explains how Fourier-transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–Vis) analysis, equilibrium isotherms and kinetic models contribute to interpretation of adsorption. FTIR changes may suggest altered functional-group environments but do not uniquely establish a binding mechanism. Calibrated UV–Vis measurements estimate residual dissolved dye concentration when matrix effects and alternative losses are controlled. Langmuir and Freundlich equations describe equilibrium behavior, whereas pseudo-first-order and pseudo-second-order models empirically describe uptake kinetics. A high coefficient of determination alone does not establish monolayer coverage, equivalent sites or chemisorption. Reliable interpretation requires controls, reproducibility, uncertainty analysis and complementary characterization. No raw spectra, measured capacities or fitted constants are reported; the figures are conceptual schematics or reproduced from open-access literature with attribution.
Keywords:
activated carbon; dye adsorption; FTIR; UV–Vis spectroscopy; adsorption isotherms; kinetic modeling.
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