1. Desalination rate and salt permeability of zero-emission DTRO reverse osmosis membrane elements

The principle of desalination rate is to remove the percentage of soluble impurities from the system influent through the DTRO reverse osmosis membrane. The salt permeability refers to the percentage of soluble impurities in the influent that pass through the membrane. The relationship between them is described by the following expression:

Desalination rate = (1-salinity content of produced water/salinity content of influent) × 100%

Salt permeability = 100%-desalination rate

2. Water production of zero-emission DTRO reverse osmosis membrane elements

Water production refers to the water production performance of the reverse osmosis system, that is, the amount of water permeating the membrane per unit time, usually expressed in tons/hour or gallons/day. The permeation flow rate is also an important indicator for expressing the water production of DTRO reverse osmosis membrane elements. It refers to the flow rate of permeate per unit membrane area, usually expressed in gallons per square foot per day. Excessive permeation flow rate will lead to an increase in the water flow rate perpendicular to the membrane surface, aggravating the pollution of the membrane elements.

3. Recovery rate of membrane elements

Recovery rate refers to the percentage of feed water converted into product water or permeate in the membrane water treatment system. The recovery rate of DTRO reverse osmosis membrane elements is determined at the time of design and is based on the preset influent water quality. The recovery rate is usually expected to be maximized in order to improve economic benefits, but its limit should be that there will be no precipitation in the membrane system due to supersaturation of impurities such as salts.

Reverse osmosis is very precise and has a very high removal rate for viruses, bacteriophages and bacteria. However, it should also be noted that in many cases, microorganisms may still re-grow on the membrane water side, which mainly depends on the way of assembly, monitoring and maintenance. In other words, the ability of a system to remove microorganisms depends on whether the system design, operation and management are appropriate rather than the properties of the membrane element itself.