Optimized removal of cationic dye by using chemically activated and pyrolyzed carbon from date palm fiber

This paper aims to manufacture a low-cost activated carbon (AC) from date palm fiber material via chemical activation with H₃PO₄. Various acid/carbon impregnation ratios (30%, 60%, 100%, and 150%) were prepared and characterized using BET, FTIR, SEM, and TGA/DTG analysis. The optimal impregnation ratio obtained was 150%. AC150% was used as an adsorbent for the MB dye. The Box-Benken design (BBD) was utilized to optimize retention parameters such as pH, dye concentration, temperature, and contact time. Twenty-nine experiments were carried out using the Box-Behnken design. With an optimal R² score of 0.9954 and an appropriate link between the variables and response, the quadratic model was determined to be the best fit. The optimal conditions for MB dye adsorption onto AC150% were identified. The results indicate that the retention conditions had a significant influence on MB color removal. The ideal parameters for 96.99% MB elimination were obtained at an initial concentration of 400 mg.L⁻¹, a pH of 5.65, a contact time of 60 min, and a temperature of 35 °C. Kinetic and equilibrium analyses were also performed to assess the efficiency of the generated AC under optimal MB elimination conditions. The pseudo-second-order model and the Langmuir isotherm provided a good fit to the experimental data, with an elevated adsorption capacity of 763.35 mg.g⁻¹. According to the experimental results, AC150% has the potential to be used as an adsorbent in wastewater treatment processes to remove organic pollutants.