Tuesday, November 14, 2006 - 8:30 AM

Reduction of Phamaceutical Compounds from Municipal Wastewater in a Constructed Wetland, Orlando, FL.

John White, Wetland Biogeochemistry Institute, Louisiana State University - Agronomy & Environmental Management, Louisiana State University, Dept. of Oceanography & Coastal Sciences, Baton Rouge, LA 70803, Marco A. Belmont, Univ of Toronto, Dept of Geography, 45 Saint George St, Toronto, ON M5S 3G3, Canada, and Chris D. Metcalfe, Trent Univ, Environmental and Resource Studies, Peterborough, ON K9J 7B8, Canada.

Traditionally, municipal wastewater treatment plants have been designed to remove pathogens, suspended solids, organic material, nitrogen and phosphates from domestic sewage. Recently, there has been concern domestic wastewater may be a source of organic microcontaminants that can impact the aquatic environment.  Pharmaceutically active contaminants (PhACs) released in wastewater may produce biological responses in plants, invertebrates and vertebrates, or may lead to antibiotic resistance of microorganisms in the environment. While there have been several studies of the removal of PhACs from municipal wastewater using conventional treatment technologies, this is the first report on the loading and treatment effectiveness of PhACs in a large constructed wetland from a municipal wastewater treatment facility. Here we show that of the 9 compounds detected in the wetland influent, trimethoprim, pentoxifylline, gemfibrozil, caffeine and ibuprofen were not detected in surface water discharged from the wetland while four of the pharmaceuticals studied, including fenoprofen, cyclophosphamide, cotinine and carbamazepine were detected in the effluent.  Removal efficiencies for the compounds by the treatment wetland ranged from 25% for fenopren to 100% for several drug compounds.  Annual loading rates to the wetland for all these compounds ranged from 0.39 – 8.55 kg y-1.  Wetland treatment has led to a significant reduction of just over 77% of the mass of these compounds, which without wetland treatment, would be discharged into the adjacent river.  Impacts of these compounds on the environment, as well as the fate processes for PhACs in wetlands are of great concern because these compounds are biologically active, contain a complex mixture of drugs and their effects on the vast majority of biota in wetland systems are unknown.