A tube well painted red indicates that its water is arsenic-contaminated and can be used for any purpose other than drinking and cooking. Photograph by Shehzad Noorani/UNICEF.

The National Academy of Engineering (NAE) has announced the winners of the 2007 Grainger Challenge Prize for Sustainability. The contest sought innovative solutions for removing arsenic from drinking water that is slowly poisoning tens of millions of people in developing countries. Three prizes have been awarded from a field of more than 70 entries.

The prizewinners are recognized for the development, in-field verification and dissemination of effective techniques for reducing arsenic levels in water. The systems must be affordable, reliable, easy to maintain, socially acceptable and environmentally friendly. All of the winning systems meet or exceed the local government guidelines for arsenic removal, and require no electricity.

The prizes were presented at a gala dinner in Washington, D.C., on Feb. 20.

Abul Hussam, an associate professor in the department of chemistry and biochemistry at George Mason University received the Grainger Challenge Gold Award of $1 million for his SONO filter, a household water treatment system.

Arup Sengupta, John Greenleaf, Lee Blaney, Owen Boyd and Arun Deb, and the nonprofit organization Water for People, shared the Grainger Challenge Silver Award of $200,000 for their community water treatment system.

The Children’s Safe Drinking Water Program at Procter & Gamble Co. (P&G) was awarded the Grainger Challenge Bronze Award of $100,000 for the PUR Purifier of Water coagulation and flocculation water treatment system. The program’s director, Greg Allgood, accepted the prize for P&G.

The Gold Award-winning SONO filter is a point-of-use method for removing arsenic from drinking water. A top bucket is filled with locally available coarse river sand and a composite iron matrix (CIM). The sand filters coarse particles and imparts mechanical stability, while the CIM removes inorganic arsenic. The water then flows into a second bucket, where it again filters through coarse river sand, then wood charcoal to remove organics, and finally through fine river sand and wet brick chips to remove fine particles and stabilize water flow. The SONO filter now is manufactured and used in Bangladesh.

The system developed by the Silver Award-winning team is applied at a community’s wellhead. Each arsenic removal unit serves about 300 households. Water is hand-pumped into a fixed-bed column, where it passes through activated alumina or hybrid anion exchanger (HAIX) to remove the arsenic. After passing through a chamber of graded gravel to remove particulates, the water is ready to drink. This system has been used in 160 locations in India. The water treatment units, including the activated alumina sorbent, are being manufactured in India, and villagers are responsible for their upkeep and day-to-day operation. The active media are regenerated for re-use, and arsenic-laden sludge is contained in an environmentally safe manner with minimum leaching.

The PUR Purifier of Water technology that won the Bronze Award combines chemicals for disinfection, coagulation and flocculation in a sachet that can treat small batches of water in the home. It is simple, portable and treats water from any source. First, the sachet contents are stirred into a 10-liter bucket of water for five minutes. As the water rests for another five minutes, arsenic and other contaminants separate out. The water then is poured through a clean cloth to filter out the contaminants. After another 20 minutes to complete the disinfection process, the water is safe to drink. As part of P&G’s focal philanthropy program, the Children’s Safe Water Drinking Program has worked with partners to provide 57 million sachets in more than 30 countries over the past three years, enough to purify more than 570 million liters of safe drinking water. Each sachet is about the cost of an egg.

Solutions to a Global Problem

Arsenic contamination is prevalent in neighboring Bangladesh and West Bengal, India, where a quarter of the population drinks water from shallow tube wells – an inexpensive, low-tech way of accessing ground water. Many of the estimated 10 million tube wells were built with international aid to provide an alternative to bacteria-tainted surface water. Unfortunately, these wells frequently tap into aquifers contaminated by arsenic. In the United States, most communities with arsenic-laden ground water have installed expensive, centralized cleanup technologies. Different solutions are required for less developed parts of the world with limited resources.

Arsenic poisoning is a slow, painful process that ultimately can result in cancer and death. Debilitating sores appear first and are followed by nerve damage, often in the hands and legs, which are especially sensitive to arsenic. Affected people can have difficulty working or even walking, and continued exposure can lead to liver failure, kidney failure and the amputation of arms or legs.

“The primary purpose of the Grainger prize is to accelerate the development and dissemination of technologies that enhance social and environmental sustainability for the benefit of current and future generations,” says NAE president William Wulf. “The prize stimulates innovation, initiative and marketing of good ideas. A complementary goal of the prize competition is to increase awareness within the U.S. engineering community of the importance of designing and engineering for sustainability, particularly in an international context, and to encourage and showcase efforts by U.S. engineers to bring sustainable technologies to the marketplace and to promote green design philosophies,” Wulf adds.

The goal of this particular challenge was chosen with the assistance of an advisory panel expert in the area of sustainable development. A committee of Academy members made the selection of the recipients with expertise in water chemistry, manufacturing, environmental engineering and public health.

The Grainger Challenge Prize for Sustainability is made possible through the generous support of The Grainger Foundation. The prize was administered and managed by the National Academy of Engineering.