International Journal of Scientific Research and Engineering Development

Soda feldspar, a naturally abundant and inexpensive mineral, was investigated as an adsorbent for the removal of methyl violet (MV) dye from aqueous solutions. Batch adsorption experiments were carried out to examine the influence of key operating parameters, including contact time, solution pH, and adsorbent dosage. The adsorption performance was found to depend strongly on these parameters, with optimum conditions observed at a contact time of 90 min, pH 7, and adsorbent dosage of 20 g L⁻¹with a maximum dye removal efficiency of 95.4%. The adsorption kinetics were evaluated using pseudo-firstorder and pseudo-second-order models. Among them, the pseudo-second-order model showed a much better correlation with the experimental data (R² = 0.99). Equilibrium data were analysed using Langmuir, Freundlich, Temkin, Redlich–Peterson, and Dubinin–Radushkevich isotherm models. The Langmuir model provided the best fit (R² = 0.99) with a maximum adsorption capacity of 3.91 mg g⁻¹, suggesting predominantly monolayer adsorption on the adsorbent surface. Thermodynamic analysis revealed negative Gibbs free energy values confirming the spontaneous nature of adsorption, while the positive enthalpy change (ΔH° = 11.521 kJ mol⁻¹) indicated that the process is endothermic. Overall, the results demonstrate that soda feldspar can serve as a promising, environmentally friendly, and cost-effective adsorbent for the treatment of dye-contaminated wastewater.

Madhusudhana Reddy. Mule, G.V.S.Sarma, K.V.Ramesh, K. Sarath Chandra,"Soda Feldspar as a Natural Mineral Adsorbent for Methyl Violet Removal from Aqueous Solutions: Equilibrium, Kinetic, and Thermodynamic Studies" International Journal of Scientific Research and Engineering Development, V9(3): Page(1715-1724) May-June 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.