Nature’s filter: Wetlands clean selenium from agricultural runoff

Researchers have found a natural detox program for selenium-contaminated farm runoff in the form of wetland vegetation and microbes. Results from a two-year study show that man-made wetlands in California’s San Joaquin Valley were able to remove an average of 69.2 percent of the selenium in agricultural drainage water. More significantly, some plant populations showed remarkable promise at converting selenium into a harmless gas consisting primarily of dimethyl selenide. That means less of the selenium would end up in sediment or plant tissue.