What is used to measure the performance of reverse osmosis (RO) systems?

The performance of reverse osmosis (RO) systems is best measured by percent rejection. This metric indicates how effectively the RO system removes contaminants from the feed water. The percent rejection value is calculated by comparing the concentration of specific solutes in the feed water to that in the permeate (the treated water).

A high percent rejection indicates that the system is successfully filtering out contaminants, ensuring that the water produced is of a high quality. It is a crucial performance indicator in assessing the overall efficiency and effectiveness of an RO system. When evaluating an RO unit, monitoring this percentage helps operators understand the system's capability to meet water quality standards, which is essential for both health and operational efficacy.

While water flow rate, pressure differentials, and filtration efficiency are relevant to the overall functionality of an RO system, they do not directly convey how well the system is purifying the water in terms of the contaminants removed. Percent rejection specifically quantifies the system's filtration performance, making it the most critical measure in this context.