Why Is The Strength Of Ion Exchange Resin Reduced?

First, the main reasons for the reduction of the strength of ion exchange resin are:

1. The ion exchange resin is decomposed due to the action of strong oxidants, which reduces the strength of the resin. This situation mostly occurs in the positive resin, for example, due to the control of residual chlorine in the water. But the negative resin by the serious pollution of organic matter will also degrade and affect its strength. From the experience of operation, it is necessary to reduce the oxygen consumption of influent to below 1mg/L (27℃, potassium manganate oxidation for 4h), and some foreign regulations of influent oxygen consumption <0.3mg/L.

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

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

4. Because the volume expansion of the resin is too large in the operation, for example, the expansion rate of the resin during the transformation is too fast and 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 when used, such as the condensate recovery water temperature is relatively high, which often causes the resin to break and reduce the strength.

6. Due to improper storage of resin, dry water loss, once it meets water, it will burst; Or the ambient temperature is lower than 0 ° C, due to the freezing of water inside the resin and swelling, crushing, resulting in reduced strength of the resin.

Second, how to separate anion and cation exchange resin after mixing?

In practical work, resins are often mixed and need to be separated. Separation method:

Mixed resin soaked in saturated salt solution, after a certain time of stirring, using the relative density of Yin and Yang resin in saturated salt solution, the floating and sinking performance is different. The strong acid anion exchange resin will float in the upper layer, and the strong acid cation exchange resin will sink in the bottom layer, from which it will be separated.

Iii. What does it mean that the ion exchange resin becomes darker after use?

An ion exchange resin is a translucent or transparent substance that varies in color depending on its composition. All styrene resins are yellow. Acrylic resins are colorless and transparent, and some are milky white. Generally speaking, the crosslinking agent is more, the impurities in the raw material are more, and the color of the resin produced is deep.

After the ion exchange resin is used for a period of time, its color will become darker due to the pollution of iron or organic matter in the water. The color of the failed ion exchange resin is slightly darker than that of the regenerated resin.