Of all the resource shortages in the world, you wouldn't think water—on a planet covered by more than
326 million cubic miles of the substance—would be one of the most serious. Yet, the
United Nations Development Program estimates nearly a billion people lack access to clean water.
The problem is that most water—around 96%—is salt water, and the remaining 4% isn't always where it needs to be. Even when it is available, quite often it is contaminated and unfit to drink. The result, according the UNDP, is that every day, an average of 5,000 children die from water and sanitation-related diseases.
A simple problemBut Andrew Hudson, a technical advisor for the U.N. development agency, says even though such a small percentage of the earth's water is drinkable, there's enough for everyone. What's more, says Nigel Grace, an environmental engineer based in Florida, “The technology exists to treat almost anything to a standard that is safe for human consumption.”
Grace says there are three basic steps to purifying fresh water, and they are not particularly high-tech or recent developments. You need to coagulate any particles in the water, usually by adding something to the water, like iron salt. Then you filter it. Grace says this can be very low-tech—for instance, pass the water through a box filled with sand or another granulated substance, leaving the contaminants behind. The final step is to add chlorine to kill any pathogens, and then it's ready and safe to drink.
But, Grace says, low-tech doesn't mean free. Chlorine costs a few hundred dollars a ton. Paying people to operate the system and maintain it costs money. So does pumping it through the pipes to consumers.
Likewise, one of the most common ways to take salt out of water, reverse osmosis, relies on electricity to create enough pressure to push water across a filter. In developing countries, electricity is often unreliable, expensive, or simply unavailable—and that's not even counting the cost of building a desalination plant, maintaining it, and training the people to operate it.
New technologies being testedThere are a number of groups working on how to make clean water less expensive. One of the latest developments, created by a scientist at Yale University and being marketed by a company called
Oasys Water, would use osmosis in a new way to desalinate water. Instead of needing a huge amount of electricity to create pressure to reverse the natural process of osmosis, this new technique uses regular “forward” osmosis. On one side of the membrane is saltwater. But the other side contains a special chemical mixture that activates the osmosis in that direction, pulling water through the membrane away from the salt. And the chemical mixture is designed in a special way—Oasys is keeping those details secret—so that it can be removed easily from the water.
Benjamin Jabbawy, co-founder and operations and development manager of Oasys says, “The new technique cuts the amount energy required by an order of magnitude—10% of the energy of reverse osmosis.”
Jabbawy says the company started with the idea of selling the technology in the developed world, but he hopes there will be developing-world applications as well. “If we can actually prove this and put our money where our mouths are, this is going to be really applicable from a charitable standpoint,” he says. For now, Oasys is working on proving the concept in the developed world—its first pilot plant is being tested at Yale. The company plans to open a larger test plant in January 2010 and move on from there.
Another new technology takes a different approach to obtaining fresh, clean water—pulling it from the air. “We take the moisture that exists in the air and we draw it into the system,” says Rick Howard, CEO of
Element Four, and then, essentially the same way humidity turns into rain, the air is cooled to cause the water vapor to condense into liquid.
Howard says the technology could have a huge impact in places where fresh groundwater—like rivers or wells—is unavailable or very far away. In those places, people can have to hike long distances, he says, “to bring back water that is sometimes not even pure.” He says by pulling water out of the air, you could give them back that time, “and enable them to do things that advance them more personally and as a family unit.”
Even when there is a local river, atmospheric water can have an advantage. For one thing, Element Four's water “cell” includes a coating on the condensation coils that kills some microbes. But more importantly, Howard says, “a myriad of things contained in ground water”—manufacturing plants that dump into waterways, diarrhea-causing bacteria, pollution from agriculture—don't show up in atmospheric water, because when water evaporates, many contaminants are left behind. Of course, in the driest places, where it hardly ever rains, there isn't much water in the air to condense into drinking water. Howard says even in those places, there is some humidity, usually late at night. But his technology is unlikely to be a viable solution in all cases.
Recent research in Minnesota aimed at tweaking current technology for treating wastewater could provide a different alternative—with an appealing side benefit for generating energy.
Jason Willet works for metropolitan water council in the Twin Cities, and he's working with the University of Minnesota Institute on the Environment to strip out phosphorous and nitrates in wastewater by using algae. Witter says using algae could help cut the costs of current processes for cleaning wastewater—and the algae species they're testing are high in oil, so after they ingest the chemicals from the wastewater, the researchers hope they'll be able to turn the algae into biofuel.
There could even be a third use for the algae, Willet says, since there's a shortage of usable phosphorous to be used as fertilizer. Once the oil is extracted from the algae for fuel, the leftover cell mass could be sold to fertilizer companies.
A lesson from the desertA tiny desert country with low rainfall, a growing population, and little access to freshwater, Israel has shown that with innovation and investment, even the driest places can make do.
Israeli scientists pioneered modern drip irrigation, so tiny drips of water fall exactly where they're needed to make crops grow. They have innovated with desalination technology, to reduce the amount of electricity required—and therefore the cost—by about 10% to 15%. And, says Tal Harmelin, water project manager for Israel NEWTech, a part of the Ministry of Industry, Trade and Labor, “Israel reuses at least 75% of waste water.” That's more than any country in the world, he says—number two on the list reuses less than 20%.
But in the developing world, money is often lacking to invest in the latest advances, and there isn't enough ongoing support to pay for maintenance.
Solutions start with better managementUltimately, says UNDP's Andrew Hudson, the problem is not technology or even investment, though those are crucial, but management. “Technology is part of the solution,” he says, “but there's no silver bullet tech solution.” Hudson says there have been “a number of experiences where fairly sophisticated water technologies have been deployed to rural settings, and the mechanisms are not put in place to maintain them.”
But the flipside, says Harmelin, is that sometimes even small tweaks to existing systems can have a major impact. “It doesn't always require a replacement of the whole infrastructure,” he says, “but finding the key locations and positioning of the correct element to tackle these issues.”
For instance, he says, the reason Israel is able to reuse so much of its wastewater is not because of a technological advance. “This is really based on traditional treatment plants,” Harmelin says, “but it's more of creating a national infrastructure or a national mandate that integrates the different parts of the water sector in each country.”
This is what is crucially lacking in many developing countries, says Hudson, and something even the best technology won't necessarily solve.
To read more case studies, visit Think+Up.
