RO membrane has strict requirements on the water quality. If the water does not meet the requirements and flows through the RO membrane membrane under high pressure for a long time, membrane blockage will occur. Therefore, it is necessary to install ultrafiltration before RO membrane. It is well known that the failure of RO membrane membrane systems is mostly due to the incomplete function of the pre-treatment system. In order to ensure the normal operation of RO membrane, the raw water must be strictly treated.
The reasons for installing ultrafiltration before RO membrane are as follows
Remove suspended solids and reduce turbidity.
Control the growth of microorganisms.
Suppress and control the deposition of micro-soluble salts.
Adjust the inlet water temperature and pH.
Remove organic matter.
Control the precipitation of metal oxides and silicon.
Due to the variety of raw water types and their complex composition, in order to meet the requirements of the main process design parameters such as raw water quality and RO membrane membrane system recovery rate, it is necessary to choose a suitable pre-treatment process system. This can reduce fouling and scaling of RO membrane membranes, prevent the decrease of RO membrane membrane desalination rate and water production rate. Especially for the current situation of increasingly scarce water resources and deteriorating water quality, choosing the correct pre-treatment system will directly affect the overall function of the RO membrane membrane system.
When your RO membrane system shows a tendency for contamination, has been stopped for a long time, or routine maintenance is required, it is recommended to clean RO membrane. When the following pollution characteristics appear (10-15% decrease in standardized water production, 10-15% decrease in standardized water quality, or a 10-15% increase in pressure drop between feed water and concentrate water), it indicates that your RO membrane system needs cleaning. Since the frequency of cleaning the RO membrane system due to fouling depends on the location, the generally accepted cleaning frequency is once every 3 to 12 months.
If you have to clean more than once a month, you should improve the pre-treatment system of RO membrane and adjust the operating parameters of the RO membrane system. If cleaning is required every 1 to 3 months, you need to work on improving the current equipment performance, but it is difficult to judge whether it is necessary to improve the pre-treatment system. In RO membrane design, the dirt in the RO membrane product water flushing system is usually ignored. Using this method can reduce the frequency of RO membrane cleaning. Soaking the RO membrane membrane component with product water during equipment shutdown can help dissolve dirt and loose sediment, thus reducing the frequency of chemical cleaning.