The reason and correct treatment of the increase of the conductivity of reverse osmosis equipment
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Update time : 2023-04-23 10:44:17
The reason and correct treatment of the increase of the conductivity of reverse osmosis equipment
As we know, electrical conductivity is an important indicator of the cleanliness of the water produced by reverse osmosis equipment. Once the electrical conductivity index is not within the standard value, the water quality must be a problem. Sometimes, after the pure water equipment has been running for a certain time, the outlet water conductivity will increase, but we will also encounter that the outlet water conductivity of the newly changed reverse osmosis membrane is still high, or when the two-stage reverse osmosis outlet water, the secondary conductivity is higher than the primary conductivity. What are these reasons?
1. Long operating life With the extension of membrane element operating life, salt permeability increases, in general, high conductivity means that the entire water treatment system compared to the initial state, no change. At this time, the reason for the high conductivity is that the aging of reverse osmosis membrane component leads to a decrease in desalination rate. The correct treatment method is to replace the reverse osmosis membrane of the reverse osmosis host. The usual replacement frequency (cycle) is once every 2-3 years.
2. The connector leaks The electrical conductivity of the equipment increases suddenly and the displacement increases during normal operation. This situation is due to the sharp increase in conductivity caused by the leakage of the sealing ring connected to the reverse osmosis membrane component. It is recommended to replace the sealing ring. The specific method is to detect the water quality of each membrane component and find out the leakage of the part of the replacement.
3. The performance of membrane components is reduced Membrane element scratches, membrane is oxidized, chemical cleaning damage. After running for a period of time, the water yield of the equipment does not change, the conductivity increases, and the displacement increases. It indicates that the membrane is degraded by oxidizing medium and the conductivity increases. Therefore, the membrane component needs to be replaced.
4. There is a lot of gas dissolved in water When the equipment is turned on, it is difficult to fall down or fall for too long. This situation is generally common in two-stage reverse osmosis. In the middle of the first and second stage, there is generally sodium hydroxide to adjust the amount of carbon dioxide in the water, and the amount of sodium hydroxide is related to the conductivity.
5. Water conductance rises The water quality of raw water is not stable, the water quality of raw water has changed, and the high conductance of raw water naturally affected the water production; Or the sand carbon purification and filtration effect of the equipment pretreatment is reduced or failed, and there is no regular and timely backwashing (water conductivity will increase accordingly); Or conductivity instrument error damage.
6. Fouling The filter element of the security filter of RO water is dirty and blocked. It is not replaced in time, and the pressure difference is large. The recovery rate is too high, the water quality is poor, the quality of scale inhibitor is poor, and the scale inhibitor is not reliable.
7. The temperature rises When the temperature of water is too high, the salt permeability increases.
8. Organic pollution The higher the purity of water, of course, its ability to dissolve substances is relatively stronger. In contact with air, such as carbon dioxide, oxygen and ammonia are easy to dissolve quickly, so that the conductivity increases quickly, including other bacterial pollution, colloidal pollution, insoluble NOM pollution, organic pollution, etc.
9. The pH value is abnormal Influent PH and other data are not in a reasonable range of control, pH value is too high or too low will seriously affect the desalination rate of membrane elements.
10. You're super stressed Ultra-high pressure operation increases salt permeability.
In addition, reverse osmosis equipment is a large system and other factors, it is recommended that after the problem, leave a daily operation record, contact the manufacturer to analyze the problem. The equipment manufacturer is familiar with the equipment system and can quickly find the problem.