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 806 West Queen St

 Southington, CT 06489


 Contact Information:

 Phone: 860-621-3630

 Fax: 860-621-0067

 E-mail: info@desct.com




Water Treatment Systems: Reverse Osmosis

Description: The general class of water conditioning equipment that uses a semipermeable membrane to separate water from the contaminants dissolved in that water. The water, under pressure, is forced through the membrane while the majority of the contaminants are rejected. Contaminant reduction is in the 70-97 percent range. Contaminants are flushed to drain while product water is carried to a storage vessel. The pressure required for the unit to function is supplied by normal line pressure or by a separate booster pump. Water production for the typical residential R/O system is 5-20 gallons per day. Water from an R/O system is primarily used for drinking and cooking purposes. The typical R/O system consists of one or more prefilters, a housing that holds the membrane, the membrane, a post filter, a storage tank, and a faucet.

Pretreatment Requirements: Knowledge of the quality of the raw water supply is essential for the proper installation and operation of a reverse osmosis drinking water system. The following basic tests should be performed before installing the R/O:


- hardness

- pH

- chlorine

- iron


- suspended solids



Hardness - Hard water will cause scale formation on the R/O membrane, thereby reducing daily production and shortening the life of the membrane. A water softener should be installed ahead of an R/O system when the water hardness exceeds five grains.

Iron - High iron level (0.5 ppm or above) can also cause fouling and shorten the life of the R/O membrane. Iron reduction may be required ahead of the system.

pH - R/O membranes must be operated within a certain pH range. When the pH of the raw water is outside that range, the membrane may be damaged or destroyed. Check the pH of the raw water before each installation. If the water is not within the required limits, pH adjustment of the water before it reaches the R/O will be necessary.

Chlorine - If the R/O membrane is thin film composite (TFC), it will be extremely sensitive to chlorine. If a chlorine residual is detected when you test the raw water, provisions must be made to remove the chlorine before it contacts the membrane. Most R/O systems provide a prefilter with the unit. On TFC systems installed on chlorinated water supplies, the prefilter must have a carbon cartridge for chlorine reduction. If one is not supplied with the system, one must be installed ahead of the R/O.

5 11 Types of Water Treatment Systems