title: Effect of redox conditions on pharmaceutical loss during biological wastewater treatment using sequencing batch reactors.
abstract: We lack a clear understanding of how wastewater treatment plant (WWTP) process parameters, such as redox environment, impact pharmaceutical fate. WWTPs increasingly install more advanced aeration control systems to save energy and achieve better nutrient removal performance. The impact of redox condition, and specifically the use of microaerobic (low dissolved oxygen) treatment, is poorly understood. In this study, the fate of a mixture of pharmaceuticals and several of their transformation products present in the primary effluent of a local WWTP was assessed in sequencing batch reactors operated under different redox conditions: fully aerobic, anoxic/aerobic, and microaerobic (DO concentration ≈0.3mg/L). Among the pharmaceuticals that were tracked during this study (atenolol, trimethoprim, sulfamethoxazole, desvenlafaxine, venlafaxine, and phenytoin), overall loss varied between them and between redox environments. Losses of atenolol and trimethoprim were highest in the aerobic reactor; sulfamethoxazole loss was highest in the microaerobic reactors; and phenytoin was recalcitrant in all reactors. Transformation products of sulfamethoxazole and desvenlafaxine resulted in the reformation of their parent compounds during treatment. The results suggest that transformation products must be accounted for when assessing removal efficiencies and that redox environment influences the degree of pharmaceutical loss.
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States. Electronic address: lstadler@umich.edu.
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Stadler
authors.affiliation: Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, United States. Electronic address: lijuansu@buffalo.edu.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Su
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States. Electronic address: christopher.moline@hdrinc.com.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Moline
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States. Electronic address: alexer@dtu.dk.
authors.forename: Alexi S
authors.initials: AS
authors.lastname: Ernstoff
authors.affiliation: Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, United States. Electronic address: dianaaga@buffalo.edu.
authors.forename: Diana S
authors.initials: DS
authors.lastname: Aga
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109, United States. Electronic address: nglove@umich.edu.
authors.forename: Nancy G
authors.initials: NG
authors.lastname: Love
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001262:Atenolol / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D003511:Cyclohexanols / Q000378:metabolism; D000069468:Desvenlafaxine Succinate; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D010672:Phenytoin / Q000378:metabolism; D012722:Sewage; D052616:Solid Phase Extraction; D013420:Sulfamethoxazole / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D014295:Trimethoprim / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D003511:Cyclohexanols; D004364:Pharmaceutical Preparations; D012722:Sewage; D014874:Water Pollutants, Chemical; D001262:Atenolol; D010672:Phenytoin; D014295:Trimethoprim; D013420:Sulfamethoxazole; D009584:Nitrogen; D010100:Oxygen; D000069468:Desvenlafaxine Succinate
keywords: Microaerobic; Pharmaceuticals; Redox environment; Transformation product; Wastewater treatment