Ion-Exchange Resin
The use of ion-exchange resin generally encompasses two concepts. Firstly, it can be utilized for the deep treatment of heavy metal wastewater, especially when the metal concentration in the water is very close to the standard. The stable treatment capability of ion-exchange resin can serve as the final treatment unit. Secondly, it is employed for high-concentration heavy metal wastewater at the process end, where it hasn't yet mixed with other sources. Through ion exchange, the relatively pure metal can be concentrated into a dense liquid, with an efficiency of approximately 70-80% recovery rate. The adsorbed metal is then desorbed by the recovery unit, and the unabsorbed resin is replaced to continue system operation.
In the context of deep treatment, it can target difficult-to-treat metal ions. The ion-exchange resin is used to exchange heavy metal ions in water for removal. However, ion-exchange resin is susceptible to poisoning. Taking electroplating processes as an example, multiple rinses are often used to clean the surface of parts after the electroplating tank. In order to maintain the quality standards of the workpiece, the rinsing water is designed for circulation and additional replenishment to achieve cleaning purposes, and the overflow water is treated to remove pollutants. The metal salts used in metal processing are inorganic compounds that can be removed from water by ion-exchange resin. During the ion exchange process, the resin exchanges hydrogen ions (H+) for positively charged ions (such as nickel) and exchanges hydroxyl ions (OH-) for negatively charged substances (such as sulfates and chlorides).
