可与水中离子发生离子交换反应的物质叫做离子交换剂。
The substance that can react with ions in water is called ion exchanger.
离子交换剂的种类很多，但在水处理中采用的主要是离子交换树脂和磺化煤两类。
There are many kinds of ion exchange agents, but the main ones used in water treatment are ion exchange resin and sulfonated coal.
离子交换树脂的种类也很多，按其结构特征，可分为凝胶型、大孔型和等孔型；
There are many kinds of ion exchange resins. According to their structural characteristics, they can be divided into gel type, large pass type and equal pass type.
按树脂母体种类，可分为苯乙烯系、酚醛系和丙烯酸系等；
According to the type of resin matrix, it can be divided into styrene system, phenolic system and acrylic system;
按其交换基团性质，可分为强酸性、弱酸性、强碱性和弱碱性；前两种带有酸性交换基团，称为阳离子交换树脂，后两种带有碱性交换基团，称为阴离子交换树脂。后两种带有碱性交换基团，称为阴离子交换树脂。磺化煤为兼有强酸型和弱酸型交换基团的阳离子交换剂。
According to the nature of exchange group, it can be divided into strong acid, weak acid, strong alkaline and weak alkaline; the first two with acid exchange group are called cation exchange resin, and the last two with basic exchange group are called anion exchange resin. The latter two with basic exchange groups are called anion exchange resins. Sulfonated coal is a kind of cation exchanger with strong and weak acid exchange groups.