ScienceDaily (Dec. 21, 2010) — Every hour, an enormous quantity and variety of human-made chemicals, having reached the end of their useful lifespan, flood into wastewater treatment plants. These large-scale processing facilities, however, are designed only to remove nutrients, turbidity and oxygen-depleting human waste, and not the multitude of chemicals put to residential, institutional, commercial and industrial use.
So what happens to these chemicals, some of which may be toxic to humans and the environment? Do they get destroyed during wastewater treatment or do they wind up in the environment with unknown consequences?
New research by Rolf Halden and colleagues at the Biodesign Institute at Arizona State University seeks to address such questions. The group's results, reported recently in the Journal of Environmental Monitoring, suggest that a number of high production volume (HPV) chemicals -- that is, those used in the U.S. at rates exceeding 1 million pounds per year, are likely to become sequestered in post-treatment sludge and from there, enter the environment when these so-called biosolids are deposited on land.