The amount of reject water produced by a reverse osmosis unit is dependent on which factors?

The amount of reject water produced by a reverse osmosis (RO) unit is indeed influenced significantly by the feed pressure and the number of stages in the RO system. When the feed pressure is increased, it allows for a greater volume of water to pass through the membrane, which can lead to an increase in the permeate flow and can also affect the concentration of contaminants in the reject stream.

Additionally, having multiple stages in a reverse osmosis process can improve the recovery rate and can effectively manage the concentration of solutes, thereby influencing the amount of reject water generatively. Each stage allows for further treatment of the permeate that flows to the next stage, which in turn can modify the amount of water being rejected in the process. Therefore, both feed pressure and the configuration involving multiple stages play crucial roles in determining the volume of reject water.

Other factors such as membrane age, water temperature, and ambient pressure do have effects in different contexts but do not directly relate to the immediate operational efficiency and performance regarding reject water volume. Membrane age can influence permeability over time, but it is not a determining factor in how much reject water is produced at a given time as feed conditions change. Similarly, while temperature influences the viscosity and dynamics of water flow,