Water Treatment of Ion Exchange Resin

　　The water treatment of ion exchange resin is reversible and occurs at the interface between solid resin and aqueous solution. Ion exchange resins can be divided into styrene resin and acrylic resin according to their matrix types. The main properties and types of resins are determined by the types of chemical active groups in resins. Firstly, it can be divided into cationic resins and anionic resins, which can exchange ions with cations and anions in solution respectively. Cationic resins can be divided into strong acidity and weak acidity. Anionic resins can be divided into strong alkalinity and weak alkalinity. Ion exchange resin is composed of classification name, skeleton (or gene) name and basic name. The pore structure is divided into two types: gel type and large pore type. All macroporous resins with physical pore structure are added "big hole" before the full name. If the classification is acidic, the word "yang" should be added before the name, while the classification is alkaline, and the word "yin" should be added before the name. Such as: macroporous strong acidic styrene cation exchange resin. In aqueous solution, the functional groups attached to the ion exchange resin skeleton can separate the exchange ion B + and B + can move freely in a wide range and diffuse into the solution. Ion exchange resin is composed of classification name, skeleton (or gene) name and basic name. The pore structure is divided into two types: gel type and large pore type. All macroporous resins with physical pore structure are added "big hole" before the full name. If the classification is acidic, the word "yang" should be added before the name, while the classification is alkaline, and the word "yin" should be added before the name. Such as: macroporous strong acidic styrene cation exchange resin. At the same time, the same type of ion A + in solution can also diffuse into the whole resin structure, and the concentration difference between the two ions promotes the exchange between them. The greater the concentration difference, the faster the exchange rate. Ion exchange resins have different adsorption properties for different ions. This selectivity is related to the functional groups, the skeleton structure and the degree of crosslinking of the resin itself, as well as the concentration and valence of ions in the solution. Generally speaking, the higher the ionic valence, the greater the attraction and affinity of static electricity to the functional groups of resins; the more atoms of covalent ions, the higher the selectivity of resins to resins. Because cation exchangers can exchange cations with water, cation exchangers can exchange anions with water. Therefore, by choosing a suitable exchanger, all impurity ions in water can be removed and pure water can be prepared. Cation exchange resins used to prepare pure water are acidic. The major exchange genes are sulfonate, carboxyl or phenol groups, which exchange H + with metal ions in water. Anion exchange resins are alkaline, and their exchange groups are mainly quaternary amine [- N (CH3) 3OH], primary amine (- NH2) and other basic genes. OH_2 can exchange anions with water. The treated water can be exchanged successively with H~+ cation exchanger and OH_anion exchanger to obtain purified water.