On average there are 50 to 75 significant desalination projects per year in the United States with an average capacity of approximately 1 million gallons per day. The majority of these projects utilize membrane processes such as nanofiltration (NF) or reverse osmosis (RO).
Although China ranks sixth in the world in total water resources, there is a shortage. The average water resources per capita is 2,300 m3, making it only one fourth of the world average per capita, while the unit plantation area of water resources is only one half the world’s average value.
Groundwater resources throughout northern China are drying up at an astonishing rate.
Part one of this article appeared in the February issue and described how nanofiltration, reverse osmosis and electrodialysis reversal are being run side-by-side at the Brackish Water Demonstration Facility in California.
The Diablo Canyon Power Plant at Avila Beach in California utilizes seawater for both cooling water and makeup water for steam generation. Ionics, Inc., Watertown, Mass., designed and built and now operates a complete water treatment system serving the high-purity water needs of this power plant. Over the past eight years, the seawater treatment section has demonstrated excellent long-term performance as a result of strong design, consistent maintenance and qualified operators.
In Port Hueneme, California, a state-of-the-art desalination facility uses three brackish water desalination technologies: reverse osmosis (RO), nanofiltration (NF) and electrodialysis reversal (EDR), operated side-by-side to produce over three million gallons per day (mgd) of high quality drinking water. The Brackish Water Reclamation Demonstration Facility (BWRDF) is the cornerstone of the Port Hueneme Water Agency’s (PHWA) Water Quality Improvement Program. In addition to providing desalted water for local use, the BWRDF also serves as a full-scale research and demonstration facility.
After a hurricane in the 1960s caused salt water from the Atlantic Ocean to seep into private wells-effectively destroying the drinking water-Kill Devil Hills in Dare County, N.C., took action. Today, four water treatment facilities provide safe, clean and healthy fresh water for residents and tourists.
Two technologies currently are used by Dare County for the treatment of water. The first is a conventional ion exchange method that softens well water. The second is a reverse osmosis (RO) procedure that desalts brackish groundwater from wells drilled down 300 to 400 feet.
Products at Work
Sensors and Analyzers Prove Instrumental in Preserving Civil War Sub: Recovered Submarine Requires Chloride Removal to Prevent Rust and Corrosion
The following interview is with Robert Huehmer, who currently is process manager with USFilter?s (a Vivendi Water company) Memcor, Microfloc and General Filter products division, located in Timonium, Md.
The when, where and how treatment is applied.
Demand for a cheaper way to transform saltwater into fresh has spurred the development of a new technology by AquaSonics International, Inc., the Rapid Spray Distillation (RSD) process, that desalinates water at a fraction of the cost of current methods.
Products at Work
At Work on Groundwater Treatment