Following on from my post about London’s most recent sewage incident, which killed over 3,000 fish, I take a look at NASA’s contribution to sewage treatment, improved air quality and biofuels …
In August this year, the third worst drought in Texas forced municipal water managers in Big Spring to consider recycling sewage water. The effluent, which would typically be discharged into a creek, would be treated and blended with potable water. In essence, shortening a process that would normally occur naturally, but with greater results.
This process isn’t as extreme as one might initially think, after all, a tank on the International Space Station collects and cleans urine to recover water for drinking, cooking and cleaning. Similar distillers and filters on the space shuttle Endeavor produced 6,000 pounds of potable water each year from the sweat and urine of astronauts!
In the 1970s NASA began to investigate the uses of sewage for this purpose. NASA’s research lead them to look at the environment’s ability to clean itself of pollutants. BC Wolverton, an environmental scientist who initially worked with the military to clean up environmental messes, was tasked with using plants to clean waste water at the NASA Center. It was identified that water hyacinths (commonly seen as invasive, nuisance weeds), thrive on sewage; absorbing and digesting the minerals in wastewater, giving clean water from sewage effluent!
Today, water hyacinths are used to handle sewage in cities across the United States, such as in the city of Hercules, Georgia, where a 350,000-gallon-per-day water hyacinth wastewater treatment plant has been built. Despite this, water hyacinths still receive bad press, this year a water hyacinth invasion in California has caused the ‘weed’ to clog waterways, decreasing oxygen levels and killing plankton.
In the 1980s, Wolverton also worked on tackling indoor air quality, at a time when the Skylab space station was found to be emitting toxic gasses and when 30% of offices in the US were giving office workers Sick Building Syndrome. Plants were once again identified as being able to vastly improve air quality. In association with the Associated Landscape Contractors of America (ALCA), the NASA Clean Air Study identified indoor plants that help to eradicate toxic agents such as benzene, formaldehyde and trichloroethylene from the air.
NASA’s decades of research have undoubtedly created better environments for living, on earth as well as in space, and innovative environmental technologies continue to be developed. In 2009, NASA linked the production of algae-based fuel with a process of treating wastewater. In the simple process, algae is put into plastic bags (or OMEGA bags: offshore membrane enclosures for growing algae) filled with sewage. The semi-permeable bags are floated on the ocean, letting freshwater out while preventing seawater from entering. The bags, which are designed to last up to three years, work on three levels: producing biofuels, cleansing municipal wastewater and isolating CO2 emissions. Discover more about NASA’s OMEGA project here!
- NASA list of air-filtering plants
- Five green NASA inventions
- Water & effluent treatment on ESI.info
- Air quality on ESI.info