What if we could convert wastewater into fresh water with less energy than it takes to manage wastewater facilities?
That's exactly what a Missouri University professor has done, with a new system that provides cleaner wastewater with technology that requires less energy and maintenance.
That might sound impressive as is, but it's even better than that: this system can even be retrofitted to work with existing wastewater treatment plants.
Dr. Jianmin Wang, professor of civil, architectural and environmental engineering at Missouri S&T, developed the system to save energy on the wastewater treatment process. According to Wang, nearly 1 percent of all of America's energy use goes towards managing wastewater facilities.
Most wastewater facilities work like so: treatment plants use energy to put air into their tanks. This creates oxygen that microorganisms feed on. The current system keeps the levels of oxygen in the tanks at about 2 milligrams per liter. This amount keeps the microorganisms "happy."
However, Wang points out that these microorganisms aren't actual employees and don't belong to labor unions so their level of happiness is unimportant. However, giving the microorganisms less than 2 milligrams per liter of oxygen extends their lives and increases their efficiency, all at a 30 percent less energy cost than the current method.
Wang, however, didn't stop there. He also developed a system called an Alternating Anaerobic-Anoxic-Oxic (A30) technique. Basically this removes pollutants from wastewater, along with nitrogen and phosphorus, without the use of chemicals. It also uses 10 percent less energy than current similar treatments.
Technology like the A30 could increase the world's accessibility to fresh water. An abundance of nitrogen and phosphorus has a habit of damaging water, creating algae that decompose when they die, which uses up water's valuable oxygen. Less oxygen means that other things in the water die, such as fish and plants. Algae also produce toxins that pollute water, making it undrinkable.
"It is happening in Lake Erie, many other places in the nation and throughout the world," says Wang.
A third system Wang developed is an anaerobic digester, that basically takes wastewater sludge and turns it into biogas. Wang states that his system produces 10 percent more energy than current methods. It also operates itself, so requires less energy to work.
"Advances such as these demonstrated by Professor Wang represent the next wave of wastewater management," says Dr. Glen Daigger, past president of the International Water Association. "Given growing water and resource constraints on the planet, we must turn to sources such as used water - to both supplement our water supply and to do this with a reduced environment footprint."
