title: Bromide Sources and Loads in Swiss Surface Waters and Their Relevance for Bromate Formation during Wastewater Ozonation.
abstract: Bromide measurements and mass balances in the catchments of major Swiss rivers revealed that chemical industry and municipal waste incinerators are the most important bromide sources and account for ∼50% and ∼20%, respectively, of the ∼2000 tons of bromide discharged in the Rhine river in 2014 in Switzerland. About 100 wastewater treatment plants (WWTPs) will upgrade their treatment for micropollutant abatement in the future to comply with Swiss regulations. An upgrade with ozonation may lead to unintended bromate formation in bromide-containing wastewaters. Measured bromide concentrations were <0.05 mg L(-1) in ∼75% of 69 WWTPs, while they ranged from 0.4 to ∼50 mg L(-1) in WWTPs with specific bromide sources (e.g., municipal waste incinerators, landfill leachate, and chemical industry). Wastewater ozonation formed little bromate at specific ozone doses of ≤0.4 mg O3/mg DOC, while the bromate yields were almost linearly correlated to the specific ozone dose for higher ozone doses. Molar bromate yields for typical specific ozone doses in wastewater treatment (0.4-0.6 mg O3/mg DOC) are ≤3%. In a modeled extreme scenario (in which all upgraded WWTPs release 10 μg L(-1) of bromate), bromate concentrations increased by <0.4 μg L(-1) in major Swiss rivers and by several micrograms per liter in receiving water bodies with a high fraction of municipal wastewater.
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland.
authors.forename: Fabian
authors.initials: F
authors.lastname: Soltermann
authors.affiliation: ERZ Entsorgung + Recycling Zürich , CH-8050 Zürich, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Abegglen
authors.affiliation: Envilab , CH-4800 Zofingen, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Götz
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland.|Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich , CH-8092 Zürich, Switzerland.|School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: von Gunten
mesh_terms: D001959:Bromates; D001965:Bromides; D010126:Ozone; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical; D018508:Water Purification
chemical_list: D001959:Bromates; D001965:Bromides; D010126:Ozone; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical