Removal of reactive dye from textile wastewater using durian seed activated carbon

Reactive dyes are recognized as problematic due to their high color content and chemical oxygen demand (COD) in wastewater. The discharge of reactive dye wastewater leads to organic pollution in surrounding water bodies, negatively affecting the aquatic ecosystem. Due to the low biodegradability of reactive dyes, wastewater treatment becomes challenging, posing difficulties for treatment plant operators. Various techniques have been employed to remove reactive dyes from wastewater, with adsorption being one of the most effective methods. In this study, durian seeds were used to produce activated carbon for the removal of Cibacron Red FN-R reactive dye from an aqueous solution. The produced durian seed activated carbon (DSAC) underwent physical and chemical characterization analyses. The adsorption experiment was conducted to determine the adsorption efficiency of DSAC in terms of color and COD reduction percentage. Color removal decreased from 58.94% to 0.96% as the adsorbate concentration increased (50-250 mg/L). COD removal initially increased from 21.99% to 53.91% at 50-100 mg/L and then declined to 35.29% at 200 mg/L, followed by a slight increase (4.17%) at 250 mg/L. A preliminary study was conducted to evaluate the effect of selected operating variables (pH, adsorbent dose, initial dye concentration, and contact time) on the adsorption process. The adsorption efficiency improved with an increasing adsorbent dosage, with the optimum dosage of 1.0 g achieving removal efficiencies of 41.33% and 56.65% for color and COD, respectively. However, a negative effect on color and COD removal was observed when the initial solution pH increased from 3 to 9. The adsorption process was more effective at lower initial dye concentrations. Furthermore, the adsorption data fitted well with the Langmuir equilibrium model and the pseudo-second-order kinetic model, with R² values of 0.9567 and 0.9611, respectively. PRACTITIONER POINTS: Sustainable Adsorbent: Durian seed-based activated carbon (DSAC) offers an eco-friendly solution for textile wastewater treatment by utilizing agricultural waste. Effective Pollutant Removal: DSAC achieved removal efficiencies of 41.3% for color and 56.7% for COD under optimal conditions. Optimal Conditions: Best performance observed at 1.0 g adsorbent dosage, low pH, and lower initial dye concentrations. Model Reliability: Adsorption behavior fits well with the Langmuir isotherm and Pseudo-Second-Order kinetic models, aiding system optimization. Practical Consideration: High pH reduces efficiency, highlighting the need for pH control in real-world applications.