Mathematical Modelling of Zinc Removal from Wastewater by Using Nanofiltration and Reverse Osmosis Membranes

The present work aimed to study the efficiency of nanofiltration (NF) and reverse osmosis (RO) process for treatment of heavy metals wastewater contains zinc. In this research, the salt of heavy metals were zinc chloride (ZnCl2) used as feed solution. Nanofiltration and reverse osmosis membranes are made from polyamide as spiral wound module. The parameters studied were operating time (0 70 min), feed concentrations for zinc ions (10 300 mg/l), operating pressure (1 4 bar). The theoretical results showed, flux of water through membrane decline from 19 to 10.85 LMH with time. Flux decrease from 25.84 to 10.88 LMH with the increment of feed concentration. The raise of pressure, the flux increase for NF and RO membranes. The maximum recovery was 99 % and 57 % for NF and RO respectively. In general, polyamide nanofiltration and reverse osmosis membranes give a high efficiency for removal of zinc. The separation efficiency of heavy metals in reverse osmosis membrane higher than nanofiltration membrane. While the water flux in NF process higher than RO process. The water flux theoretically calculated is a function of pressure, feed temperature, feed concentration, feed flow rate and time.