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Why Does The Strength Of Ion Exchange Resin Decrease?

Jul 22, 2020

 ion exchange resin is one of the most commonly used raw materials in the water treatment field. Due to the characteristics of ion exchange resin, its strength will gradually decrease during use. Why is this? The editor is here today to popularize science for everyone.

   The strength of the ion exchange resin is reduced and the main reasons for the breakage are:

   1. The ion exchange resin decomposes due to the action of a strong oxidant, which reduces the strength of the resin. This situation mostly occurs in cation resins, for example, due to excessive control of the residual chlorine in the influent water. However, the serious pollution of the anion resin by organic matter will also degrade its strength. Operating experience shows that it is necessary to reduce the oxygen consumption of the influent water to below 1mg/L (27℃, potassium permanganate oxidation for 4h), and some foreign countries stipulate that the oxygen consumption of influent water is <0.3mg/L.

   2. The ion exchange resin is damaged due to repeated mechanical friction, such as frequent backwashing, rapid hydraulic transportation, excessive exchange flow rate, air and ultrasonic scrubbing, etc., which affect the strength of the resin.

   3. Because ion exchange resins sometimes operate under high pressure and high flow rate conditions, the pressure difference between the inlet and outlet water is too large, and the resin is crushed and loses its strength.

  4. Because the volume expansion of the resin is too large during the operation, for example, the expansion speed of the resin during the transformation is too fast or too large, and the strength of the resin is reduced by repeated expansion and contraction.

  5. The thermal stability of the resin is poor, and the water temperature is too high during use. For example, the high temperature of the condensed water recovery water will often cause the resin to break and reduce the strength.

  6. Due to improper storage of the resin and drying out of water, it will burst and crack once it meets with water; or the ambient temperature is lower than 0℃, and the resin's internal moisture freezes and bursts and breaks, causing the strength of the resin to decrease.