Current research, is a study on elimination of Nickel and Lead heavy metal ions from drinking water by nanofiltration membrane. Product flow (Q f ), recovery rate, heavy metal ion rejection and concentrate saturation factor have been used as membrane performance determinants. pH value, Feed Flow(Q f ) and operating pressure (P) have been used as system operating variables. In the first series of experiments, influence of operating conditions on the removal efficiency of Nickel ion in the form of Nickel Sulfate has been discussed. Results showed that, Nickel rejection increases with increasing pressure and feed flow but it doesn't depend on the pH value. Maximum and minimum rejection of 98.1% and 90.8% has been obtained for Nickel ion respectively. Fouling factor has slightly increased with increasing pressure and decreasing feed flow. It strongly depends on pH value and increases with increasing pH value. Product flow depends only on operating pressure. After that optimization of operating conditions for obtaining maximum Nickel removal performance of membrane has been done. According to the results, membrane has its highest efficiency at P=5.8bar, Q f =75.6 L/hr and pH=5.5. In this condition, Q p =22.5 L/hr, Recovery=30% and Nickel Rejection=93.5% has been obtained. Then effect of Nickel concentration on membrane performance has been discussed. In the next series of experiments, influence of operating conditions on Lead removal of nanofiltration in the form of Lead Nitrate has been studied. Results followed the same trends as for the Nickel removal; except slight decrease of Lead removal with increasing pH value (due to difference in electric valence of studied anion and cation).And also optimization of operating conditions for obtaining Lead removal performance has been done. The resultant conditions are almost the same with those obtained for Nickel.In this conditions Q p =22.5L/hr, Recovery=30% and Lead rejection= 86% has been obtained. In the next step influence of Lead concentration on membrane's performance has been discussed. Finally heavy metal removal from solutions containing Nickel and Lead simultaneously have been studied. In the optimum conditions 90% of Lead and 92% of Nickel have been removed by membrane.
