PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

The filtration efficiency of the jatropha polyurethane (JPU) membrane, enhanced with bio-based carbon dots (CDs) derived from oil palm empty fruit bunch carboxymethylcellulose, was evaluated for real-world applications, specifically for the removal of lead (Pb(II)) ions. Using a central composite design (CCD) within response surface methodology (RSM), the parameters for JPU/CD membranes with a 0.65 wt% carbon-dot loading were investigated and optimized. Pressure of range 1.5–2.5 bar, feed concentration from 100 to 200 ppm, and solution from pH (9 to 13 were fed into the RSM. An optimum Pb(II) ion removal of 82% was predicted at conditions of pH 11, 135 ppm, and 2 bar, while the validated experimental result recorded 67% Pb(II) ion removal. A statistically non-significant term was excluded from the analysis through backward elimination to improve the model’s accuracy. The quadratic regression model was significant (R² = 0.90) for the optimization prediction. Therefore, the results from the reduction model implied a satisfactory membrane performance, offering a better prediction for Pb(II) ions removal. The addition of CDs alters the membrane structure and properties, leading to improved water permeability and Pb(II) rejection, and positioning the bio-based JPU/CDs membrane as a promising sustainable solution.