title: Comparison of methylisoborneol and geosmin abatement in surface water by conventional ozonation and an electro-peroxone process.
abstract: In this study methylisoborneol (MIB) and geosmin abatement in a surface water by conventional ozonation and the electro-peroxone (E-peroxone) process was compared. Batch tests with addition of ozone (O3) stock solutions and semi-batch tests with continuous O2/O3gas sparging (simulating real ozone contactors) were conducted to investigate O3decomposition, •OH production, MIB and geosmin abatement, and bromate formation during the two processes. Results show that with specific ozone doses typically used in routine drinking water treatment (0.5-1.0 mg O3/mg dissolved organic carbon (DOC)), conventional ozonation could not adequately abate MIB and geosmin in a surface water. While increasing the specific ozone doses (1.0-2.5 mg O3/mg DOC) could enhance MIB and geosmin abatement by conventional ozonation, this approach resulted in significant bromate formation. By installing a carbon-based cathode to electrochemically produce H2O2from cathodic oxygen reduction, conventional ozonation can be conveniently upgraded to an E-peroxone process. The electro-generated H2O2considerably enhanced the kinetics and to a lesser extent the yields of hydroxyl radical (•OH) from O3decomposition. Consequently, during the E-peroxone process, abatement of MIB and geosmin occurred at much higher rates than during conventional ozonation. In addition, for a given specific ozone dose, the MIB and geosmin abatement efficiencies increased moderately in the E-peroxone (by ∼8-9% and ∼10-25% in the batch and semi-batch tests, respectively) with significantly lower bromate formation compared to conventional ozonation. These results suggest that the E-peroxone process may serve as an attractive backup of conventional ozonation processes during accidental spills or seasonal events such as algal blooms when high ozone doses are required to enhance MIB and geosmin abatement.
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Weikun
authors.initials: W
authors.lastname: Yao
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Qiangyong
authors.initials: Q
authors.lastname: Qu
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600, Dübendorf, 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
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China. Electronic address: wangyujue@tsinghua.edu.cn.
authors.forename: Yujue
authors.initials: Y
authors.lastname: Wang
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D010126:Ozone; D006861:Hydrogen Peroxide
keywords: Bromate; Drinking water treatment; Hydrogen peroxide; Ozone; Taste and odor compounds