Ion Exchange and Reverse osmosis both process help in the removal of contaminants from water. Sometimes, both methods in combination can offer effective results. Still, both these methods are different and affect the specific application. Both these methods depend upon the target substances. Here, we have given a comparative study on the effectiveness of both of these methods.
Removal of Hardness
If calcium and magnesium are available in a process stream, it can cause scaling to the RO membrane and lower its life. To improve the RO’s efficiency, the Ion Exchange process takes place before its entrance to an RO system. While it is not a cost-effective procedure, but it helps in a total reduction of contaminants and after that, you can get access to pure water.
Removal of Bacteria
During the water treatment process, bacterial reduction helps in improving the quality of water. Ion Exchange process is not effective in de-activating pathogens available in the water. Certain chemical processes further degrade resins, so you need to exercise care in removing these materials and preventing excessive resin regeneration. Pathogens are significant; hence, RO system is the best option. Other kinds of membrane filtration, like ultrafiltration, are also highly effective in removing viruses and are cost-effective. In some instances, physical separation happens with the help of chemical or UV disinfection.

Suspended Solids
RO differentiates different contaminants depending upon size, which means any particles or molecules that are too large to pass via RO membrane clogs the pores. For this reason, RO can easily remove hard solids. Though it is not ideal for this purpose because such materials can increase the cost and reduce the life span of the RO membrane, but Ion Exchange process is unsuitable in removing the solids. It may cause clogging and less performance of resin beds. Hence, if water has suspended solid particles in it, it is better to use the combination of both the methods.
Ion Exchange Produces Less Wastage Than RO
If we calculate or look at the process in detail, we will see IX provides 2-4% less wastewater, and RO rejects as much as 10-50% wastewater. Therefore, the areas where water capacity is in the limit, or there is high-waste water; the Ion exchange process is more effective.
Regeneration life
Both processes need periodic regeneration and operational components. The service life of both methods is different. For Ion Exchange, regeneration of resins occurs after 4-10 years, and for the RO membrane, the life span is 3-5 years.
Both methods help the filtration of water or softening of water, but you should select the process and keep these points in mind.