What is indicated by a percent rejection rate in a reverse osmosis system?

The percent rejection rate in a reverse osmosis (RO) system is a crucial metric that indicates the efficiency of the filtration process. It quantifies the percentage of contaminants, dissolved solids, and other impurities that are effectively removed from the feed water by the RO membrane. A higher percent rejection rate signifies that the system is doing a better job of purifying the water, meaning that it is effectively filtering out undesirable substances.

Understanding this concept is vital for evaluating the performance of an RO system in various applications, including drinking water purification and industrial processes. If the percent rejection rate decreases, it may indicate membrane fouling, degradation, or other issues requiring attention to maintain purification efficiency.

The other options do not directly relate to the function of the percent rejection rate. The size of the filter pores is a characteristic of the membrane but does not specifically convey the performance of the filtration. Water temperature can affect system performance but is not indicated by the rejection rate itself. Likewise, while flow rate is important for system design and operation, it does not provide direct insight into how well the system removes contaminants. Thus, the efficiency of the filtration process is accurately represented by the percent rejection rate, making the first choice the correct one.