The influence of divalent ions on the rejection of carbamazepine in the presence of humic acid by nanofiltration

Effect of calcium and magnesium ions and Natural Organic Matter (NOM) on the removal of carbamazepine (CBZ) was investigated by nanofiltration in this study. Water matrix which was used in these experiments was Tehran tap water and deionised water (DI) as control group. Effect of magnesium and calcium ions were examined by doubling the amount of target ions in tap water and Humic Acid (HA) was used as NOM. All the experiments have been conducted at three pressures to have more diverse operational condition. Rejection of carbamazepine in the presence of HA increased both in DI water and tap water; however, rejection was decreased in higher pressure due to concentration polarization. Both Ca^2 + and Mg^2 + decreased the CBZ rejection by reduction of CBZ-HA complexation; particularly, Ca^2 + was more effective.