In the use of reverse osmosis plants for water treatment, usually due to various reasons resulting in reverse osmosis plant can not run continuously for a long period of time.
When the reverse osmosis plant is out of service for more than a certain period of time, according to the length of time the reverse osmosis plant out of service to develop different maintenance measures.
First: Short-term shutdown (no more than 48 hours)
1. Use membrane system product water as feed water to flush (low-pressure high flow rate) the reverse osmosis membrane plant.
2. Prevent air from entering the system and close the relevant piping and valves after flushing until the conductivity of the concentrated water and the influent water are consistent.
3. To prevent bacterial growth, need to flush every 24 hours according to the above method, if the ambient temperature is higher than 27℃, the flushing frequency should be adjusted to once every 12 hours.
Second, long-term shutdown (more than 48 hours)
1. Carry out a chemical cleaning and sterilization treatment.
2. Prepare (1.0% sodium bisulfite) protection fluid for circulating flushing and filling the reverse osmosis plant, and close all valves to prevent air from entering the reverse osmosis plant to make the protection fluid fail.
3. Check the pH value of the protective solution every week, and replace the protective solution immediately when the pH is less than 3.
4. Flush and replace the protective fluid every 30 days as above, if the ambient temperature is higher than 27℃, the time should be shortened to 15 days.
5. The reverse osmosis plant storage temperature should be controlled at (5-45)°C during the shutdown.
6. When the plant is used again, please flush the reverse osmosis plant with low pressure and high flow rate of produced water for more than 1 hour, then flush with high pressure (5-10) minutes until the produced water is qualified;
Note that the produced water discharge valve of the membrane system should be fully opened before flushing to avoid back pressure and unqualified produced water into the tank.