NF Membrane Parameter Variation under Certain System Conditions

Feed Pressure The NF membrane productivity increases linearly with rise in feed pressure. The salt rejection increases as the feed pressure rises. However, no significant increase is observed after reaching a certain level.

Feed Temperature The NF membrane productivity increases linearly with rise in feed temperature. The salt rejection decreases as the feed temperature rises. That's because the diffusion rate of salt through the membrane accelerates as the temperature rises.

Recovery Under a constant feed pressure, the productivity gradually drops as the recovery goes up while the salt rejection sharply decreases at a moment.

Feed TDS Under a constant feed pressure, the higher the feed TDS, the lower the productivity. Consequently, the salt rejection also decreases.

Feed pH The productivity remains unchanged as the feed pH goes up. The salt rejection remains unchanged within a certain range. Both too high and too low pH values will lead to a decrease in the salt rejection.