What is RO?

Reverse osmosis (RO) has become a common method for the treatment of household, commercial and industrial drinking water supplies. Effectiveness of RO units depends on initial levels of contamination and water pressure. RO treatment may be used to reduce the levels of:
1) Naturally occurring substances that cause water supplies to be unhealthy or unappealing (foul tastes, smells or colors).
2) Substances that have contaminated the water supply resulting in possible adverse health effects or decreased desirability.

RO systems are typically used to reduce the levels of total dissolved solids and suspended matter. The principal uses of reverse osmosis in water industry are for the reduction of high levels of nitrate, sulfate, sodium and total dissolved solids.

RO units with carbon filters may also reduce the level of some SOCs (soluble organic compounds) like pesticides, dioxins and VOCs (volatile organic compounds like chloroform and petrochemicals). An RO unit alone may not be the best solution for these types of contaminants, but installing a properly design-ed RO unit to reduce the levels of other contaminants may provide a reduction in SOCs and VOCs.

Reverse osmosis is sometimes referred to as ultrafiltration because it involves the movement of water through a membrane as shown in Figure 1. The membrane has microscopic openings that allow water molecules, but not larger compounds, to pass through. Some RO membranes also have an electrical charge that helps in rejecting some chemicals at the membrane surface. Proper maintenance is essential to retain effectiveness over time. Some units are equipped with automatic membrane flushing systems to clean the membrane.

Water Treatment Technology Process

Mineral water making process