Highlighting Water Purification Technology

The DC-based research and consulting firm Social Technologies recently released a series of 12 briefs that shed light on the top areas for technology innovation through 2025. The brief on universal water, by futurist Peter von Stackelberg, is the eighth trend in the series.

"The ability to produce abundant, cheap, clean water has been a reality for much of World 1 for at least a century," explains von Stackelberg. "Large-scale water purification and distribution systems have been fundamental to better health and longer lives, and have made possible comfortable modern lifestyles."

In Worlds 2 and 3, he notes, efforts focused on providing clean water have contributed to significant improvements in health and lifestyle as well. However, even the availability of water hangs in the balance for much of the world's population.

"Water is becoming increasingly scarce," says von Stackelberg, pointing to the fact that less than 2% of the planet's ample water store is fresh, and much of that is threatened by pollution. "By 2025, about 3.4 billion people will live in regions that are defined by the UN as water-scarce."

While much of the future of universal water depends on political and social activity, technological advances in three major areas will be critical for the hydrological future: desalination of seawater or brackish groundwater, purification of water containing chemical or biological contaminants, and conservation to cut demand.

• Flash desalination. One approach is flash desalination, a process that heats water and then evaporates it in a low-pressure chamber; it has been in use for decades but is energy-intensive and costly. Indian scientists developed a developed a low-temperature, thermal-desalination demonstration facility that cuts energy input by pumping water seawater from the surface and flash evaporating it at very low pressure. The vapor is then condensed using cold deep-sea water.
• Water harvesting. Captured rainwater can supplement other sources of water. In Beijing, for instance, the National Stadium built for the 2008 Olympic Games is designed with a nano-filtration system and underground pools that can capture and process up to 100 tons of rainwater an hour. Seattle's King Street Center, a 327,000-square-foot commercial building constructed in 1999, captures rainwater for use in the building's sewage system and for landscaping needs, saving about 1.5 million gallons of water a year.
• Smart water application technologies (SWAT). This is one way to curb water usage. For instance, irrigation of residential landscapes typically applies 30-40% more water than needed. But a system that has been tested in California, Washington, and several other western states has linked sensors that monitor rainfall and soil moisture to a "smart" controller. Water consumption has decreased by an average of 26%, with some consumers cutting their usage by as much as 59%.

Challenges Ahead:

Multiple challenges--from growing populations to economic development to climate change--will result in increasing pressure on water supplies in many regions, even in World 1 countries. Ultimately, public attitudes about water may prove to be the largest challenge in implementing new technologies.

• Climate change. Global climate change could have dramatic impacts on water supplies, complicating efforts to meet demands. As sea levels rise, saltwater is likely to contaminate freshwater aquifers in coastal areas as well as intruding into rivers and freshwater estuaries. "Rain and snowfall patterns may change as a result of climate change, altering the amount of precipitation that entire regions receive, and weather extremes will likely cause droughts that limit water supplies, and floods that knock out water and sewage treatment infrastructure," von Stackelberg says.
• Changing water attitudes. "A paradigm shift will be required if water shortages are to be avoided," von Stackelberg insists. Among these newer attitudes are the beliefs that human waste is a resource from which water can be harvested, and that storm water is a resource which needs to be captured and stored.

Forecasts:

"The future of universal water is simple," von Stackelberg suggests. "Use less, keep the available freshwater clean, and make more fresh water from saltwater to offset critical shortfalls."

He points to the following three game changers that may impact the future:

• Low-cost power for desalination. Major advances in the production of cheap energy could fundamentally change the economics of desalination for coastal regions. Low-cost alternative energy sources are among the surest ways to cut the cost of producing freshwater, whether by removing salt or other impurities.
• Nanowater: High-tech filtering. Nanoparticles, nano-tubes, and other nanomaterials may substantially increase the efficiency of the water desalination and purification processes, and may offer methods for removing new contaminants that are constantly being introduced into the environment.
• Nature-inspired water use: Use less, pollute less. Reducing demand for process water in high-use industrial applications as well as achieving zero wastewater discharge will be crucial for ensuring future water supplies. Garnering lessons from living organisms and natural systems is one of the driving principles behind green engineering, a movement to improve the environmental impact of products and processes.