An article in the May 2010 issue of Stormwater magazine discusses the issue of antibiotics and various other medications as well as personal care products—fragrances, sunscreens, cleaning products, and the like—ending up in surface waters and, potentially, in drinking water supplies. Removing these substances once they’re in the water is tricky, as several people interviewed in the article point out. Researchers at Michigan Technological University, however, working with phytoremediation, claim that a plant commonly used for erosion control is effective at removing antibiotics from the water supply.
Vetiver grass has a deep and complex system with high tensile strength, leading to its use as a means of erosion control on steep slopes and streambanks. Growing vetiver under controlled conditions in water containing two antibiotics, tetracycline and monensin, that are commonly given to cattle, researchers found that the plant removed more than 95% of the monensin and virtually all the tetracycline. The vetiver with the antibiotic-laden water supply also grew faster than that grown in uncontaminated water.
Previous research has also shown vetiver to be effective at removing nitrogen, phosphorus, heavy metals, and some herbicides and pesticides from water.
Another common use for vetiver, ironically, is as an ingredient in perfume—one of the products of concern making their way into the water supply. Perhaps the plant has a chance to redeem itself. A next step in the research, though, is to study what happens to the antibiotics once they’ve been taken up by the vetiver and to examine ways of ultimately disposing of them.