Circular Economy-Driven Methomyl Pesticide Removal from Water through Peanut Shell Activated Carbon Adsorption

Water pesticide contamination poses an environmental challenge, necessitating the development of effective and sustainable removal methods. This study investigates the use of peanut shell-derived activated carbon (PSAC) to efficiently remove Methomyl, a common carbamate pesticide, from water. Peanut shells were transformed into activated carbon through chemical modification using nitric acid, and its adsorption performance for Methomyl was evaluated. The study employs a Box-Behnken Design to optimize adsorption by systematically varying key variables such as initial concentration, adsorbent dose, and contact time. The results revealed that the PSAC exhibited excellent adsorption capability for Methomyl, with an optimal removal efficiency of 94.06% at optimal conditions: 562 ppm initial concentration, 0.50 g adsorbent dosage, and 55 min contact time. Moreover, the study revealed that the adsorption occurred heterogeneously in multi-layers, with Freundlich being the best fit (R² = 0.9928) and following pseudo-second-order kinetics (R² = 0.9988), indicating that the adsorption mechanism is achieved via chemosorption. A remarkable adsorption capacity of 56.62 mg/g was attained, emphasizing the PSAC’s high efficacy in pesticide removal from contaminated water. Overall, using PSAC is promising for sustainable and cost-effective solutions to address pesticide pollution in aquatic environments, safeguarding both ecosystems and human health.