title: Mass Balance Assessment for Six Neonicotinoid Insecticides During Conventional Wastewater and Wetland Treatment: Nationwide Reconnaissance in United States Wastewater.
abstract: Occurrence and removal of six high-production high-volume neonicotinoids was investigated in 13 conventional wastewater treatment plants (WWTPs) and one engineered wetland. Flow-weighted daily composites were analyzed by isotope dilution liquid chromatography tandem mass spectrometry, revealing the occurrence of imidacloprid, acetamiprid, and clothianidin at ng/L concentrations in WWTP influent (60.5 ± 40.0; 2.9 ± 1.9; 149.7 ± 289.5, respectively) and effluent (58.5 ± 29.1; 2.3 ± 1.4; 70.2 ± 121.8, respectively). A mass balance showed insignificant removal of imidacloprid (p = 0.09, CI = 95%) and limited removal of the sum of acetamiprid and its degradate, acetamiprid-N-desmethyl (18 ± 4%, p = 0.01, CI = 95%). Clothianidin was found only intermittently, whereas thiamethoxam, thiacloprid, and dinotefuran were never detected. In the wetland, no removal of imidacloprid or acetamiprid was observed. Extrapolation of data from 13 WWTPs to the nation as a whole suggests annual discharges on the order of 1000-3400 kg/y of imidacloprid contained in treated effluent to surface waters nationwide. This first mass balance and first United States nationwide wastewater reconnaissance identified imidacloprid, acetamiprid, and clothianidin as recalcitrant sewage constituents that persist through wastewater treatment to enter water bodies at significant loadings, potentially harmful to sensitive aquatic invertebrates.
authors.affiliation: Biodesign Center for Environmental Security, The Biodesign Institute, Global Security Initiative, and School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-5904, United States.
authors.forename: Akash M
authors.initials: AM
authors.lastname: Sadaria
authors.affiliation: Biodesign Center for Environmental Security, The Biodesign Institute, Global Security Initiative, and School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-5904, United States.
authors.forename: Samuel D
authors.initials: SD
authors.lastname: Supowit
authors.affiliation: Biodesign Center for Environmental Security, The Biodesign Institute, Global Security Initiative, and School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-5904, United States.
authors.forename: Rolf U
authors.initials: RU
authors.lastname: Halden
mesh_terms: D007306:Insecticides; D012722:Sewage; D053719:Tandem Mass Spectrometry; D014481:United States; D062065:Wastewater; D053833:Wetlands
chemical_list: D007306:Insecticides; D012722:Sewage; D062065:Wastewater