Recovery rate: Refers to the percentage of feed water converted into product water or permeate in a membrane system. The membrane system is designed based on the preset feed water quality, and a concentrate valve on the concentrate line allows adjustment and setting of the recovery rate. The recovery rate is often desired to be maximized to obtain the maximum product water output, but its limit should be set so that the membrane does not precipitate due to supersaturation of salts or other impurities.
Desalination rate: The percentage of total soluble impurities removed from the system feed water through a reverse osmosis membrane, or the percentage of specific components such as divalent ions or organic matter removed through a nanofiltration membrane.
Salt permeation rate: The opposite of the desalination rate; it is the percentage of dissolved impurities in the feed water that permeate through the membrane.
Permeate: The purified product water produced by the membrane system.
Flow rate: Flow rate refers to the rate of feed water entering the membrane element, usually expressed in cubic meters per hour (m³/h) or gallons per minute (gpm). Concentrate flow rate refers to the portion of the "feed water" that leaves the membrane element system without permeating the membrane. This concentrate contains soluble components from the raw water source and is usually expressed in cubic meters per hour (m³/h) or gallons per minute (gpm).
Fluorescence: The rate of permeate flow per unit membrane area, typically expressed in liters per square meter per hour (l/m²h) or gallons per square foot per day (gpm).
Dilute solution: The purified aqueous solution, the permeate from a reverse osmosis or nanofiltration system.
Concentrated solution: The portion of the solution that did not permeate the membrane, such as the concentrate from a reverse osmosis or nanofiltration system.