The team, which called itself Waterwerx and created stickers with the team name to affix to their cell phones during the competition, was judged on its oral presentation, written paper, bench-scale prototype and poster presentation. They were told by judges that their system had the potential to be adopted by municipal water districts.
The team's challenge was to study the efficiency and economics of magnetic treatment on brackish water in a reverse osmosis treatment plant. Cleaning brackish water is a huge industry because of the high concentration of it throughout the world and U.S., especially in the Southwest, Midwest and Southern California.
Reverse osmosis uses high pressure to drive water through a semi-permeable membrane, creating a purified stream of water and a waste stream of the concentrated brackish water.
In the last decade, reverse osmosis has become the world's leading desalination technology. In the U.S., most reverse osmosis plants are concentrated on the coasts because they can inexpensively dispose of the waste stream in the ocean.
At inland reverse osmosis plants, waste disposal is more expensive and water supply is often limited. Consequently, inland plants need to operate at the maximum recovery rate to minimize concentrated waste. However, at high rates of recovery reverse osmosis membranes tend to break down. Membrane replacement and maintenance constitute nearly 35 percent of operating costs.
The students found that cost can be cut and water saved by using magnetic treatment in tandem with a chemical precipitation process, a method already used industrially that involves adding chemicals to cut the amount of salt collecting on the membrane. This method increases water recovery from 80 percent to 96 percent, they found.
|Contact: Sean Nealon|
University of California - Riverside