The use of nanoparticles in consumer products could have hidden consequences for human health and the environment, but researchers in the U.K. have at least found a way to help remove the molecule-sized pollutants from wastewater treatment plants.
Scientists from several U.K. research centers teamed up to examine silica, a common nanoparticle. They found that nanoparticles coated with a detergent would interact with other matter in the sewage to form a sludge, which settles out and can be removed fairly easily. But that does not necessarily mean that a more sustainable future is in sight for the widespread use of nanoparticles in consumer products.
According to an article in waterandwastewater.com, The U.K. researchers (from the Centre for Ecology & Hydrology, The Science and Facilities Council, King’s College, and Oxford University) are concerned primarily with nanoparticles in medicines, health products, beauty aids, and other consumer products that almost always end up being washed down a drain – and into a sewage treatment plant. Because of their molecule and atom-sized scale, the particles defy current wastewater treatment technology. The researchers chose silica because it is one of the most commonly used nanomaterials – over one million tons are used annually to manufacture consumer products. They used the Science Council’s ISIS Neutron Source (a sort of giant microscope), which scattered neutrons in the sewage to enable the study of nanopartcles over time.
Nanoparticles in Sewage Sludge
The importance of controlling airborne nanoparticles like diesel exhaust has long been known, and removing nanoparticles from wastewater plant effluent can help stop the pollutants from entering the environment through rivers, bays, and other discharge points. However, concentrating waste nanoparticles in sewage sludge is not a completely sustainable solution. More cities are beginning to offer their treated sludge as a natural soil enhancer for farmlands and open space, so it’s important to keep harmful chemicals out of the sludge mix. In the U.S., many nanomaterials fall under the U.S. EPA because they are classified as chemical substances under the Toxic Substances Control Act, and the agency is beginning to take a more aggressive stance.
Image: wastewater treatment plant by kallerna on wikimediacommons.
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