Reverse Osmosis

The reverse osmosis process utilized by Coster Engineering is a water separation technology where dissolved contaminants in water are physically removed by passing it under pressure through a semipermeable, thin film membrane. The process is similar to the way your body’s cells absorb water. Reverse osmosis will remove up to 98% of dissolved contaminants such as; mineral, salts, metals and organic matter that may be present in a water supply. Pores in the reverse osmosis membrane are so small that only water molecules pass through. The contaminants are rejected and discarded as wastewater. A comparison of the molecular size to pore size of the reverse osmosis membrane is shown to the right.

multipstage filtration system

Approximate Rejection Rates Of Various Impurities

DISSOLVED SOLIDSREMOVAL PERCENT (%)DISSOLVED SOLIDREMOVAL PERCENT (%)
Aluminum99Magnesium99
Bacteria99Maganese99
Barium92Mercury97
Bicarbonate98Nitrate97
Bromide96Organic Pesticides99
Cadmium98Phosphate99
Calcium98Polyphosphate99
Chloride98Pottasium98
Copper99Radium98
Cyanide96Silica98
Detergents99Silicate98
Fluoride98Sodium96
Iron99Sulfate99
Lead99Zinc99