Enhanced Removal of Bemacid Red Dye Using NaOH-Activated Arundo donax: Adsorption Performance and Kinetic Modeling

The release of artificial dyes into water bodies has emerged as a significant environmental concern due to its durability, harmfulness, and detrimental impacts on ecosystems and human well-being. This research examines the elimination of Bemacid Red dye from water using sodium hydroxide (NaOH) activated Arundo donax and evaluates its adsorption efficacy against acid-treated and acetone-treated substances to determine the optimal adsorbent. Batch adsorption studies were conducted under various operational settings to assess the adsorption capacity and removal efficacy of the synthesized materials. The findings indicated that NaOH activation markedly improved adsorption efficacy by augmenting the quantity of available active sites and refining the surface properties of the adsorbent. The adsorption mechanism was examined utilizing pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models. Among these models, the pseudo-second-order equation exhibited the most favorable correlation with the experimental data, featuring a coefficient of determination nearing one and calculated adsorption capacities aligning with the observed values, suggesting that chemisorption is the prevailing adsorption mechanism. The influence of solution pH demonstrated that basic conditions were optimal for dye elimination, with adsorption occurring swiftly and achieving equilibrium in a little duration. In comparison to the acid-treated and acetone-treated specimens, NaOH-treated Arundo donax had the greatest adsorption capacity and removal efficacy. The results indicate that alkali-activated Arundo donax serves as an efficient, cost-effective, and eco-friendly adsorbent, showing significant promise for the remediation of dye-laden wastewater and presenting a viable alternative for sustainable water purification in industrial wastewater management.