How to deal with the scaling problem of titanium electrodes
Generally speaking, there are several ways to eliminate and reduce the scaling and precipitation of the electrode scaling problem caused by concentration polarization:
1. Use inverted electrode: switch the electrode regularly to change the direction of ion migration. According to the actual situation, the electrode is generally replaced once every 2-8 hours. Since then, even a slight precipitation can be effectively removed, but the frequent reversal of the electrode has relatively high requirements on the quality of the electrode, and the loss of the electrode is large, and the electrode material with high quality and strong corrosion resistance should be selected.
2. Pickling method: a small amount of precipitated scale is always produced during the operation of the electrodialyzer, especially in areas with poor water quality. After accumulating to a certain extent, it cannot be completely removed even by the method of switching electrodes. At this time, pickling should be carried out. deal with. According to the situation, regular pickling treatment is a simple and effective method to eliminate precipitation without dismantling equipment. The cycle depends on the actual situation. Generally, 1%~2% hydrochloric acid is used for circulating cleaning.
3. Limiting current method: Strictly control the working current of the electrodialyser and keep it below the limit current when polarization is generated, so as to avoid the generation of polarization.
4. Dismantling and washing method as a last resort: After long-term operation, the internal scaling is serious and cannot be eliminated by the above methods, disassemble the device, and clean the partitions and diaphragms.
5. In order to reduce precipitation and scaling, it is also very important to strengthen the treatment of raw water. Removing suspended solids, some colloidal substances and organic impurities in the raw water can prevent or reduce precipitation and scaling, and can also do pretreatment to remove the hardness of raw water, which can effectively Prevent scale formation.
