Coarse filtration

Coarse filtration: refers to mechanical filtration to remove suspended solids, colloids, turbidity, color, odor, etc. in water. The main filtration methods are clarifier, quick filter, sand filter, sand filter, multi-media filter, activated carbon filter, disc filter, high-efficiency fiber filter and so on.

Fine filtration

Fine filtration: Filter membrane made of special materials with high filtration precision. Commonly used for microfiltration membrane and cartridge filtration.

Overfiltration

Ultrafiltration: It is a kind of membrane filtration to remove macromolecules and colloids, bacteria, etc.. High filtration precision, commonly ultrafiltration membrane.

Reverse Osmosis

Reverse osmosis: reverse osmosis is abbreviated as RO, the principle is that the raw water passes through the reverse osmosis membrane under high pressure, and the solvents in the water diffuse from the high concentration to the low concentration so as to achieve the purpose of separation, purification and concentration, because it is opposite to the direction of osmosis in nature.

EDI

EDI: electrodialysis and ion exchange combined with the new process of desalination, taking electrodialysis and mixed-bed ion exchange, the use of ion exchange to do in-depth treatment, without the regeneration of pharmaceuticals, using ionization to produce H + and OH -, to regenerate the resin purpose.

Various uses of pure water

Pure water and ultra-pure water is widely used in power plants, electronics, medicine, chemical industry, through a variety of membrane filtration or ion exchange, the harmful ions in the water to remove. Power plant desalinated water used in power plants, the main indicators of desalinated water quality: hardness is equal to zero, conductivity ≤ 0.2 μs.cm, SiO2 ≤ 20 ppb. Chemical plant chemical water is diverse, usually water quality is not higher than the power plant water quality requirements, but may have requirements for certain ions, so commonly used primary or secondary reverse osmosis process. The conductivity of the effluent water is 5~10μs.cm or more. Medicine medicine water more conductivity and bacteria for the requirements of the system material material requirements, more stainless steel products. Usually after the pure water to add sterilization device.

How to prevent the scaling of RO membrane?

1) Do a good job of pretreatment of raw water to ensure that the SOI <4, and at the same time to add a biocide to prevent microbial growth;

2) In RO operation to maintain the appropriate working pressure, the general working pressure increases the water yield also increased, but too large and will make the membrane compaction.

3) In RO operation should maintain the flocculent state of concentrated water, reduce the concentration of the solution on the surface of the membrane polarization, to avoid precipitation of insoluble salts on the surface of the membrane; 4) In RO shutdown, to maintain the appropriate working pressure.

4) In RO shutdown, short-term flushing should be dosed, long-term protection should be added CH2O protective solution for protection.

5) When the RO water production is significantly reduced or salt content increases, the surface scaling or contamination, chemical cleaning should be carried out.

What is the filtration cycle?

Filtration cycle is the actual running time between two backwash

Including: filtration, backwashing, and positive washing three links

Backwashing is to remove the dirt accumulated in the filtration process, to restore the dirt-trapping capacity of the filtration media.

Positive washing is to ensure that the filtration operation? A necessary part of the qualified water, positive washing qualified to enter the cycle of operation of water production.

Reverse osmosis process principle

RO is the use of semi-permeable membranes permeable to water impermeable salt characteristics, to remove most of the salt in the water. Pressurization in the raw water side of RO, so that part of the pure water in the raw water along the direction perpendicular to the membrane through the membrane, the salts in the water and colloidal substances on the surface of the membrane concentration, the remaining part of the raw water along the direction parallel to the membrane will be concentrated substances away. There is only a small amount of salt in the permeate water, and the purpose of desalination is achieved by collecting the permeate water.