Industrial pure water process
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Recently, I was working on an industrial pure water production process, and I noticed that in some processes reverse osmosis is carried out before ion exchange, while in other processes it is done after ion exchange. What are the differences between these two approaches? Is it related to the purpose for which the pure water is to be produced?
It is determined based on the source and quality of the water. Reverse osmosis is a purely physical method for removing impurities. Ion exchange can be used to change the properties of water.
The ion exchange you mentioned, which is used before RO, is a water softener – a sodium ion exchange bed designed to remove hardness. If it is a cation-anion exchange bed, it cannot be placed before the RO.
In our facility, the water treatment process follows this sequence: tap water – filter – sodium ion exchange – RO membrane – mixed bed. Now, sodium ion exchange is no longer used; the process has become tap water – filter – (sodium ion exchange) – RO membrane – mixed bed. I’m not sure if there will be any problems with this new arrangement