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Reverse osmosis equipment requirements for water quality
- 2019-05-18-

Reverse osmosis equipment water quality requirements

Reverse osmosis is a new type of pure physical desalination process. Due to the structure, material and desalination mechanism of the reverse osmosis membrane element, the reverse osmosis equipment has higher requirements for water ingress.

Temperature conditions between 1 and 45 ° C;

pH should be in the range of 2 to 11;

The organic content (COD, mg / L) should be less than 1.5;

Turbidity (NTU) should be controlled below 1.0;

Silt density index (SDI value) <>

Residual chlorine content <0.1mg l="" (actual="" control="" at="">

Iron content (mg/L): when dissolved oxygen>5mg/L, Fe<>

Silica content (mg/L): SiO2 <100 in="" concentrated="" water;="" lsi:=""><>

Sr, Ba, etc. are easily formed into ions of insoluble salts: Ipb < 0.8="">

The latter three items can be appropriately increased in value by adding a scale inhibitor.

If one or more of the above indicators fails to meet the standard, it will have the following effects on the membrane of the reverse osmosis equipment:

1. The RO reverse osmosis membrane is contaminated by metal oxides;

2, colloidal pollution;

3. RO reverse osmosis membrane fouling;

4, suspended matter fouling RO reverse osmosis membrane;

5. Contamination of organic matter and microorganisms leads to an increase in effluent COD.

In turn, it has a negative impact on the entire reverse osmosis equipment:

Reduce the water production of reverse osmosis purified water system; reduce the water quality of reverse osmosis purified water system; increase the energy consumption of reverse osmosis equipment, including raw water and electricity; increase the cost of water treatment operation, including reverse osmosis scale inhibitor. Resin regenerated salt, other water treatment agents, and the like.

The reverse osmosis equipment pretreatment plays a role in it. When the pretreatment is not good, the quality of the reverse osmosis water is seriously not up to standard, and the time is too long, which may cause irreversible physical and chemical damage of the reverse osmosis membrane element, and greatly shorten the service life of the reverse osmosis membrane element.

The purpose of reverse osmosis equipment pretreatment is to solve the following problems to ensure the stable operation and service life of reverse osmosis equipment.

1. Prevent film surface fouling (including CaCO3, CaSO4, SrSO4, CaF2, SiO2, iron-aluminum oxide, etc.);

2. Prevent the fouling of organic substances;

3. Prevent the fouling of microorganisms;

4. Prevent colloidal substances and suspended solid particles from fouling;

5. Keep the water production of reverse osmosis equipment stable.