Water softening resins are generally divided into cation resins and anion resins. As the name suggests, the two resins are used to adsorb (exchange) cations such as Ca, Mg and anions such as NO3, SO4 and other ions in water. The cation-treated water is alkaline, and the anion-treated water is acidic, which is related to the difference in their adsorption of ions. The two resins are basically indistinguishable in appearance, both are yellow-brown, very light particles slightly larger than millet grains.

In the chemical water production workshop of the power plant, after the water passes through the cation bed (filled with cation resin) and the anion bed (anion resin), the hardness can reach zero, and the conductivity is also very low, which is the softened water. The so-called yin bed and cation bed are essentially a large tank. Hard water passes through the resin in the large tank and becomes soft water. Because the passing water has a certain pressure and flow rate, the resin is churning in the tank, so there are still some places. Calling this kind of tank a boiling bed refers to a type of thing. The process of a factory that makes pure water is probably the same, except that the pure water needs to be sterilized. The cost of producing demineralized water on a large scale is not high.

Cation resin and anion resin can be reused by regeneration. In order to ensure the quality of demineralized water, the power plant basically adopts the method of regular regeneration, rather than waiting for its effect to decline and then regenerate. Generally speaking, about once every two weeks. For recycled resin, brine can be used, but it is generally not used now because its effect cannot reach other methods. Cationic resins are generally regenerated with acid, preferably sulfuric acid, and anionic resins are regenerated with alkali, preferably sodium hydroxide.

After knowing the production process of the factory, we can use the resin according to its method and miniaturize its system. The most common method is to put anion resin and cation resin in different compartments of the external filter, because the external filter has good sealing performance, and scattering can also be considered, which basically increases the contact area and Time, the resin is fully applied, which also reflects the superiority of the external filter. When applying the upper filter, the resin can be wrapped with gauze like activated carbon, one resin is placed on the upper layer, and another resin is placed after a layer of filter cotton, and the effect is also good.

In order to increase the ion softening effect, some people make the resin pellets toss up after passing through the water in the container (or at least have a certain flow rate), increase the contact area and time, if possible, you can try it, the effect very good. There are several main points for such equipment: first, there must be a water pump that generates a certain pressure; second, there must be two cans the size of Coca-Cola bottles, which must be connected at the top and bottom; For the lost filter, the fourth is to put the resin in the proper order and quantity. The regeneration of resin can use salt, soak it for 24 hours and then take it out for reuse.

If you want to pursue the effect, you can use dilute acid or dilute lye, remember to use acid for cation and base for anion. In addition, pay attention to safety when using acid and alkali. When acid or alkali drops on the skin, immediately rinse with plenty of water, do not wipe first.所有使用树脂的方法均是在模拟工厂的制水流程，其要点是：

1、两者不要混放；     2、要让水与树脂充分接触；     3、比例恰当；     4、定期再生。