The nature of the feed water treated by the reverse osmosis plant will affect the pre-treatment components selected. Our “Water Treatment Guide” provides a comprehensive list of different feed waters and their suggested pre-treatment components.
The most common water contaminant removed via pre-treatment is suspended solids. These particulates of dust and other matter suspended in the feed water are not dissolved and have to be removed via physical filtration down to around 1 micron or less for optimal RO performance. This is because reverse osmosis membranes, the primary element of RO plants are not designed to handle large loads of non-dissolved material and will rapidly foul. Therefore appropriate pre-filtration is necessary for any reverse osmosis system to assure correct system operation and mitigate premature membrane fouling.
The nature of the feedwater will suggest the typical level of suspended solids. For example, surface waters such as rivers and dams typically have higher amounts, since the water running across the earth will pick up dirt and other particulates as it flows. While bore water extracted deep from within the earth has much lower amounts since the water is been filtered by the rocks that it passes through prior to collection. These different feed waters will, therefore, require appropriate feed water specific pre-treatment. Typically best practice for surface water is to utilise an Ultrafiltration system before the RO plant. In the case of bore water, however, a simpler multimedia filter is sufficient due to the lower levels of sediment.
Therefore the first step in designing a suitable containerised reverse osmosis plant is to collect and analyse the target feed water. This will provide all the specific water content information required for system design. The analysis information will then be used by the system design software to ensure you get a robust, efficient system that operates day in and day out without issue.