Discussion on Industrial Application of Two-stage Reverse Osmosis EDI Water Treatment


Time:

Nov 12,2021

The main task of this stage is to roughly filter the tap water to prepare for entering the reverse osmosis membrane and ensure a certain water quality before entering the reverse osmosis membrane to protect the use effect and service life of the reverse osmosis membrane. The process is to filter the tap water from the original water tank through fine sand, activated carbon and precision filters to remove impurities, organic matter, colloids, suspended solids, etc. in the water to prevent these large particles from blocking the reverse osmosis membrane after entering the reverse osmosis membrane. After coarse filtration, the water quality has been improved to a certain extent. and allowed to move on to the next link.

1. multi-media filtration

The main task of this stage is to roughly filter the tap water to prepare for entering the reverse osmosis membrane and ensure a certain water quality before entering the reverse osmosis membrane to protect the use effect and service life of the reverse osmosis membrane. The process is to filter the tap water from the original water tank through fine sand, activated carbon and precision filters to remove impurities, organic matter, colloids, suspended solids, etc. in the water to prevent these large particles from blocking the reverse osmosis membrane after entering the reverse osmosis membrane. After coarse filtration, the water quality has been improved to a certain extent. and allowed to move on to the next link.

2. primary reverse osmosis

The water that has been roughly filtered and then passes through the reverse osmosis membrane is the primary reverse osmosis. The reverse osmosis membrane is a semi-permeable membrane, which can prevent Ga2 ,Mg2 ,Fe-2 ,SO4-2,Cl-1,Na and other large ions from passing through. In order to ensure the effect of reverse osmosis and protect the reverse osmosis membrane, scale inhibitor must be continuously added to the reverse osmosis container, and the water temperature must be above 25 ℃ (steam heat exchanger is used in winter) and certain water pressure must be guaranteed, (Using a vertical pump) Under a certain pressure, the ionized water is squeezed through the reverse osmosis membrane to form two kinds of water. The water that passes through the reverse osmosis membrane is the finished water into the next link, while the water that has not passed through the reverse osmosis membrane is discharged, and the water treated by primary reverse osmosis enters the next link-secondary reverse osmosis.

3. secondary reverse osmosis

The principle of secondary reverse osmosis is the same as that of primary reverse osmosis. Its function is to further remove salt in water (Ga2 ,Mg2 ,Fe-2 ,SO4-2,Cl-1,Na plasma) to further improve the water quality. After secondary reverse osmosis, the conductivity of water quality can be close to 1MΩ.CM. After 1. secondary reverse osmosis pretreatment, the retained water becomes EDI feed water, while the water that has not passed through the reverse osmosis membrane (concentrated water) is discharged in time, and the ratio is generally 1:3, that is, for every production of one ton of qualified water, about 3 tons of concentrated water (reclaimed water) will be discharged.

Key words:

water equipment

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