Influencing factors of reverse osmosis membrane in RO water treatment

Influencing factors of reverse osmosis membrane in RO water treatment

1. Effect of inlet pressure on reverse osmosis membrane

The water inlet pressure itself does not affect the excessive salt penetration, but the increase of water inlet pressure increases the net pressure driving reverse osmosis, which increases the water yield. At the same time, the excessive salt penetration is almost unchanged. The increased water yield dilutes the salt through the membrane, reduces the salt penetration rate and improves the desalination rate. When the inlet water pressure exceeds a certain value, the concentration polarization is increased due to the high recovery rate, which will lead to the excessive increase of salt permeability, offset the increased water production, and make the desalination rate no longer increase.

2. Effect of inlet water temperature on reverse osmosis membrane

The conductivity of RO membrane water production is very sensitive to the change of inlet water temperature. With the increase of water temperature, the water flux also increases linearly. For every 1 ℃ increase of inlet water temperature, the water production increases by 2.5% - 3.0%; (based on 25 ℃)

3. Effect of influent pH value on reverse osmosis membrane

Influent pH value has little effect on water yield, but has a great effect on desalination rate. The pH value is between 7.5-8.5, and the desalination rate reaches the highest.

4. Effect of influent salt concentration on reverse osmosis membrane

Osmotic pressure is a function of the concentration of salt or organic matter in water. The higher the salt content of influent, the greater the concentration difference, and the salt permeability increases, resulting in the decrease of desalination rate.