Water treatment: Combining reverse osmosis and ion exchange

Water treatment in today's modern world requires highly technical, high performance separation products to achieve increasingly stringent treated water qualities, or to provide the lowest cost of water production. Although thin film composite membranes based on this process have been used for more than thirty years, the newest technology now offers the possibility to control the polymerization process more precisely. If the dosing is too high, even just for a short period, the cationic fouling can irreversibly foul the RO membrane surface. Apart from a well adjusted iron chloride dosing system, a lower negative surface charge is the best option to reduce the fouling potential of this event. The membrane separation composite layer is the most essential part of the RO separation process. Before use, this critical component is assembled into a device, called an RO element. The winding process for spiral wound RO elements involves many steps all of which need to be carefully controlled.