Comparative Removal of Crystal Violet Dye Using Peanut Hull Powder and Its Modified Forms: Adsorption Mechanisms, Isotherms, and Kinetics

In this work, the removal of cationic dye; Crystal Violet (CV) by (Peanut Hull Powder (PHP), activation of Peanut Hull Powder (PHPAC) with HCl, and activated carbon derived from PHP) from aqueous solution in batch experiments. The adsorbents were characterized using BET for analysis of the specific surface area. The finding showed that the adsorption capacities of PHP, PHPAC, and PHPAC were 95.5 %, 96.8 %, and 98.7 % respectively. Under ideal circumstances, the isotherms of adsorption using the Langmuir, Freundlich, Sips, and Temkin isotherm models were used to validate the experimental data. The maximum adsorption capacity (qmax), as determined by isotherm investigations, was 13.25815 mg/g. The Freundlich Model is the better-fitting model with the highest R2 value in the PHP experiments. According to the kinetic analysis, the pseudo-second-order better describes the adsorption behavior. The study found that adjusting factors like pH, temperature, contact duration, adsorbent dose, adsorbent particle size, and the stirring rate significantly improved adsorption efficiency. The results show much higher dye removal rates under these conditions at the optimum values; 6, 25°C, 60 min, 1.5 g, 150 µm, and 120 rpm for the above-mentioned conditions respectively, and offer a thorough investigation of adsorption kinetics and isotherms. This research provides new insights into the adsorption mechanism and suggests potential applications for industrial wastewater treatment, promoting more sustainable and cost-effective solutions.