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Reverse Osmosis Water Purification Unit (ROWPU)

The Reverse Osmosis Water Purification Unit (ROWPU) provides potable water from any water source. The Army's workhorse, the ROWPU produces potable water from a variety of raw water sources such as wells, lakes, seas, lagoons, rivers, oceans and ice holes. Today's modern Army relies on the ROWPU to purify brackish water and salt water. The ROWPU, resembling a large trailer, comes in a variety of sizes and uses a variety of chemicals and membranes to filter and purify water for consumption. The proper use of the ROWPU can provide purified drinking water for thousands of soldiers in a military theater.

The treatment of water is necessary to prevent various waterborne diseases, such as typhoid and dysentery. Treatment processes must control certain chemical and physical characteristics of water, such as hardness or unpleasant taste. Hence, the function of a water treatment is not only to make water safe for human consumption but also to make water more palatable, less scale forming, and more suitable for use in laundries, boiler plants, and various other places.

The ROWPU utilizes pure water extraction methods employing reverse osmosis in either a single-pass (using one membrane bank) or double-pass mode (using two membrane banks) depending on the type of water being purified. A 50-micron self-cleaning filter and a 5-micron cartridge filter provide two-stage pre-treatment. Post-treatment is by chlorination. The ROWPU has its own generator (the unit can also be hooked up to an external power source.)

The ROWPU's filters, called reverse osmosis or RO elements, are critical to desalinization and purification of water. These filters have a lifecycle of 1,000 to 2,000 operational hours. Conceivably, a ROWPU will not operate continuously or indefinitely on one set of filters. The duration of the mission will dictate down time for the ROWPU. Also, the end of deployments or training exercises and winterization of the ROWPU will result in down time.

The work of RO elements begins when the ROWPU operators feed raw water through the filters at intensified pressure. The filtration process separates impurities from the raw water, whether fresh, brackish or salt water. Then the ROWPU operators add disinfectant to the filtered water to conclude the purification process before storing the water as potable. Critical to this whole process is the proper functioning of the RO elements. ROWPU operators monitor the system's gages to monitor how well the RO elements are working. Improperly functioning filters must be cleaned or replaced.

Replacing the filter elements of the Reverse Osmosis Water Purification Unit (ROWPU) is extremely expensive, but units can keep replacement costs at a minimum with some alternatives available today. One 600-gallons per hour ROWPU with 8 filters and one 3,000-gallons per hour ROWPU with 12 filters, for example, have a combined filter replacement cost of $15,555.75. Projected Armywide, these filter replacement costs could adversely impact unit funds for soldier training. Maximizing operational hours while minimizing operational costs for the ROWPU filter elements with proper storage, equipment tests and operator training will save money.

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Page last modified: 07-07-2011 02:48:12 ZULU