Wheat Straw-Derived Activated Carbon for Efficient Removal of Methylene blue: Kinetics, Thermodynamics, and Adsorption Mechanism

Abstract

Methylene blue, a synthetic organic dye commonly used in industries, poses health and environmental concerns. In the current study, activated carbon derived from wheat straw was used as an adsorbent for removing methylene blue dye from water. The effects of various operating parameters, such as pH, contact time, temperature, mass of adsorbent, and initial concentration of the pollutant, were investigated to understand the adsorption mechanism. The results showed that the activated carbon prepared from wheat straw through a chemical activation with H3PO4 was highly effective in adsorbing methylene blue. The Langmuir isotherm provided the best fit to the experimental data, indicating favorable adsorption with a maximum adsorption capacity of 5.2548 mg/g. The kinetic study revealed that the adsorption process followed a pseudo second-order model with significant intraparticle diffusion. The process was found to be spontaneous and endothermic. The activated carbon derived from wheat straw exhibited comparable or even greater adsorption capacity compared to other agricultural by-products and commercial activated carbons. Overall, these findings suggest that wheat straw-derived activated carbon has promising potential as a low-cost adsorbent for removing methylene blue and other organic pollutants from water