It has become common to see ion exchange used in conjunction with membrane technology, especially in applications with high salinity. In the future the role of ion exchange will shift from bulk removal of ions toward selective ion removal and polishing. The use of cation resins for water softening will continue as the largest single role of resins, even as pretreatment for membrane processes. In some applications, the role of ion exchange for bulk ion removal will diminish as membrane processes become more efficient. Ion exchange polishing of membrane-treated waters will continue to grow. Ion exchange will become more widely used for selective ion removal and product recovery, and purification. Currently the areas of rapid growth in ion exchange are selective removal of contaminants such as nitrates, heavy metals, radioactive ions, and organic acids from potable water supplies and for specific metal removal from wastewater streams.

There will be increasing reliance on the companies that provide exchange tank services. Exchange tank services are ideally suited for point-of-use applications, especially in polishing membrane effluents. They allow the regeneration of the ion exchange material in bulk at centralized facilities. This includes the treatment of the regenerant wastewater. Another recent trend is for owners to contract out the operation and maintenance of the plants. This eliminates workforce, training, and management costs.