Innovation Pipeline

Water is usually an underappreciated and neglected resource. Until a city, community or village finds it depleted or contaminated.

Similarly, the energy involved in transporting and treating water is obscured, particularly its economic and environmental implications. But as developed countries come to grips with these issues, there’s an awakening about water management much different from its origins 150 years ago.

Ancient water systems generally piped water by using gravity. The onset of the industrial revolution shifted the design of water-management systems to help separate waste from drinking water to improve hygiene and reduce diseases like cholera and typhoid. Pressure, quality and quantity were all key drivers in this generation of systems.

Now, the next generation of water systems are being designed as decentralized schemes and focused on triple bottom line outcomes based on social, economic and environmental values. But this is only the beginning of a transformation to an “avatar” water system that is a former self or embodiment of the way we’ve dealt with water.

“We need to start from the point of view that nothing exists today,” says Ramesh Rengarajan, the former chief technology officer of General Electric Water and Process Technologies and currently a consultant. “There is great opportunity for distributed systems. For example, why lay down new water pipe infrastructure when a distributed infrastructure can be 30 to 40 percent cheaper?”

Rengarajan says the shift toward this new approach requires us to reexamine our thinking. For example, labeling wastewater as waste needs revisiting. We should consider water and waste two value streams, because water and energy can be recovered from them.

Remember, it takes an estimated 10 gallons of water to produce a gallon of gasoline and 30 gallons of water to produce a single slice of bread. The challenge is to design holistic new approaches that encompass outputs and inputs and arrive at a balanced equation. Otherwise, benefits are unsustainable.

Sustainable next-generation water systems require the incorporation of all three facets: energy, water and waste. For example, a water purification or desalination system that expends large amounts of energy creates economic and environmental liabilities.

Think also about the global issues facing countries that involve water scarcity, global warming and energy security. All of those issues are now challenging the existing monolithic infrastructure. Next-generation technologies are helping usher in a new era of water management that embraces the core principles of energy capture, waste energy retrieval and recycling.

Consider, for example, a microbial fuel cell system that uses the waste stream of methane as an energy source to generate electricity. And desalination systems that utilize osmotic pressure gradients instead of large amounts of electricity to drive pumps.

A bevy of enabling technologies has helped make these goals possible, including low-energy nanomembrane systems, purification systems that recapture energy and highly efficient desalination technologies. It’s no longer just about one function. It’s about being multifunctional to address the broader needs of industry, consumers and the environment.

The good news is leading-edge companies and startups are pioneering new systematic approaches that take into consideration the critical balance of energy, water and waste. And it requires a complete reset in terms of how we think about these systems. By Lee Bruno