Tannins are formed through the decomposition of plants and animals
As water passes through a chloride-form anion resin, alkalinity will be removed from the water. This results in tannins removal.
Tannin removal is an application that some dealers have felt uncomfortable tackling. Tannins, until several years ago, were treated with standard strong base macroporous anion resins manufactured with styrene and divinylbenzene. This type of resin worked well in some areas but failed in other areas. Over the last five to 10 years resins have come into the residential water market that have been more successful and have made this water treatment problem more attractive to the water treatment dealer.
It is usually recommended that the water be softened prior to the tannin removal unit. The softener removes hardness and metals (like iron) that might otherwise foul the anion resin. Tannins will pass through softening (cation) resin without any detrimental effects. Hardness levels greater than 10 grains passing into a tannin removal unit may precipitate calcium carbonate, which is a white floc that can restrict flow in the system and blind exchange sites on the resin. Metals like iron also can foul the anion resin, reducing the anions' ability to remove tannins.
The removal of tannins via anion exchange resins occurs through both an ion exchange and an absorption process. Tannins have a slightly negative charge. Because of this, they are exchanged for chloride onto the resin. It is also believed that the anion resin can absorb organics. Salt is used to regenerate the anion resin. Generally, the resin will be brined at approximately 10 lb per cubic foot salt (NaCl). It is extremely important to regenerate the resin frequently. Once the tannins are exchanged/absorbed onto the resin they will tend to migrate into the inner matrix of the resin bead. Once this occurs it is very difficult to regenerate the tannins from the resin. The system should be regenerated every two to three days. Frequent regenerations will reduce the likelihood of organic fouling. Longer regeneration intervals will promote organic fouling, whether the anion resin is acrylic or styrene based.
Tannin resin is often mixed with softening resin, which reduces the amount of space required by the equipment and reduces the cost of the system. This type of design has performed satisfactorily in many areas.
Lanlang could supply water softening resin and tannic removal anion resin.if you need them, please don't hesitate to contact us.
For package types
We could supply various type package bag, 25liter PE bag, 20kg woven bag,
Besides; the customized package is available.