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Urs von Gunten

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Related publications (155)

Critical Review on Bromate Formation during Ozonation and Control Options for Its Minimization

Ozone is a commonly applied disinfectant and oxidantin drinkingwater and has more recently been implemented for enhanced municipalwastewater treatment for potable reuse and ecosystem protection. Onedrawback is the potential formation of bromate, a possible ...

AMER CHEMICAL SOC2023

A Survey of Industrial N-nitrosamine Discharges in Switzerland

Florian Frédéric Vincent Breider, Caroline Gachet Aquillon, Urs von Gunten

N-nitrosamines are formed during different industrial processes and are of significant concern due to their carcinogenic and mutagenic properties. This study reports concentrations of N-nitrosamines in eight different industrial wastewater treatment plants ...

2023

Reactivity of Bromine Radical with Dissolved Organic Matter Moieties and Monochloramine: Effect on Bromate Formation during Ozonation

Urs von Gunten, Sung Eun Lim

Bromine radical (Br center dot) has been hypothesized to be a key intermediate of bromate formation during ozonation. Once formed, Br center dot further reacts with ozone to eventually form bromate. However, this reaction competes with the reaction of Br c ...

AMER CHEMICAL SOC2023

Effect of cetyltrimethylammonium chloride on various Escherichia coli strains and their inactivation kinetics by ozone and monochloramine

Florian Frédéric Vincent Breider, Margaux Océane Voumard, Urs von Gunten

Cethyltrimethylammonium chloride (CTMA) is one of the most used quaternary ammonium compounds (QACs) in consumer products. CTMA and other QACs are only partially eliminated in municipal wastewater treatment and they can interact with bacteria in biological ...

2022

Ozone disinfection of waterborne pathogens and their surrogates: A critical review

Urs von Gunten

Viruses, Giardia cysts, and Cryptosporidium parvum oocysts are all major causes of waterborne diseases that can be uniquely challenging in terms of inactivation/removal during water and wastewater treatment and water reuse. Ozone is a strong disinfectant t ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Tradeoff between micropollutant abatement and bromate formation during ozonation of concentrates from nanofiltration and reverse osmosis processes

Urs von Gunten

Water treatment with nanofiltration (NF) or reverse osmosis (RO) membranes results in a purified permeate and a retentate, where solutes are concentrated and have to be properly managed and discharged. To date, little is known on how the selection of a sem ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Iodide sources in the aquatic environment and its fate during oxidative water treatment - A critical review

Urs von Gunten

Iodine is a naturally-occurring halogen in natural waters generally present in concentrations between 0.5 and 100 mu g L-1. During oxidative drinking water treatment, iodine-containing disinfection by-products (I-DBPs) can be formed. The formation of I-DBP ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Application of UV absorbance and electron-donating capacity as surrogates for micropollutant abatement during full-scale ozonation of secondary-treated wastewater

Urs von Gunten

Ozonation of secondary-treated wastewater for the abatement of micropollutants requires a reliable control of ozone doses. Changes in the UV absorbance of dissolved organic matter (DOM) during ozonation allow to estimate micropollutant abatement on-line an ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Nanoplastics removal during drinking water treatment: Laboratory- and pilot-scale experiments and modeling

Urs von Gunten

Microplastics detected in potable water sources and tap water have led to concerns about the efficacy of current drinking water treatment processes to remove these contaminants. It is hypothesized that drinking water resources contain nanoplastics (NPs), b ...

ELSEVIER2022

Inputs of disinfection by-products to the marine environment from various industrial activities: Comparison to natural production

Urs von Gunten, Jin Jiang

Oxidative treatment of seawater in coastal and shipboard installations is applied to control biofouling and/or minimize the input of noxious or invasive species into the marine environment. This treatment allows a safe and efficient operation of industrial ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Photochemical oxidation of phenols and anilines mediated by phenoxyl radicals in aqueous solution

Silvio Canonica, Urs von Gunten, Stephanie Christa Remke

Reactive intermediates formed upon irradiation of chromophoric dissolved organic matter (CDOM) contribute to the degradation of various organic contaminants in surface waters. Besides well-studied "short-lived" photo oxidants, such as triplet state CDOM (3 ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Ozonation of organic compounds in water and wastewater: A critical review

Urs von Gunten, Sung Eun Lim

Ozonation has been applied in water treatment for more than a century, first for disinfection, later for oxidation of inorganic and organic pollutants. In recent years, ozone has been increasingly applied for enhanced municipal wastewater treatment for eco ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Reactions of amines with ozone and chlorine: Two novel oxidative methods to evaluate the N-DBP formation potential from dissolved organic nitrogen

Karim-Alexandre Essaied, Urs von Gunten, Lucy Victoria Brown

The composition of oxidant-reactive dissolved organic nitrogen (DON) is poorly characterized, although its ozonation is likely to form a great variety of disinfection by-products containing a nitrogen-oxygen bond (NDBPs). In this study, two chemical oxidat ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Oxidation of organic micropollutant surrogate functional groups with peracetic acid activated by aqueous Co(II), Cu(II), or Ag(I) and geopolymer-supported Co(II)

Urs von Gunten

Peracetic acid (PAA) in combination with transition metals has recently gained increasing attention for organic micropollutant abatement. In this study, aqueous Co(II), Cu(II), and Ag(I) were compared for their capacity to activate PAA. Co(II) outperformed ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Kinetic and mechanistic understanding of chlorite oxidation during chlorination: Optimization of ClO2 pre-oxidation for disinfection byproduct control

Urs von Gunten, Yun Ho Lee

Chlorine dioxide (ClO2) applications to drinking water are limited by the formation of chlorite (ClO2-) which is regulated in many countries. However, when ClO2 is used as a pre-oxidant, ClO2- can be oxidized by chlorine during subsequent disinfection. In ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Permanganate Reduction by Hydrogen Peroxide: Formation of Reactive Manganese Species and Superoxide and Enhanced Micropollutant Abatement

Urs von Gunten, Ke Xu

Permanganate (MnO4-, Mn(VII)) is widely applied at the initial stage of water treatment to, e.g., abate taste and odor compounds, Mn(II) and Fe(II). However, its selectivity limits its application for micropollutant abatement. Hydrogen peroxide (H2O2), whi ...

AMER CHEMICAL SOC2021

Enhanced transformation of aquatic organic compounds by long-lived photooxidants (LLPO) produced from dissolved organic matter

Silvio Canonica, Urs von Gunten, Stephanie Christa Remke

Dissolved organic matter (DOM) plays a crucial role in the photochemical transformation of organic contaminants in natural aquatic systems. The present study focuses on the characterization of a specific effect previously observed for electron-rich phenols ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Reaction of DMS and HOBr as a Sink for Marine DMS and an Inhibitor of Bromoform Formation

Boris Droz, Urs von Gunten

Recently, we suggested that hypobromous acid (HOBr) is a sink for the marine volatile organic sulfur compound dimethyl sulfide (DMS). However, HOBr is also known to react with reactive moieties of dissolved organic matter (DOM) such as phenolic compounds t ...

2021

Oxidation of 51 micropollutants during drinking water ozonation: Formation of transformation products and their fate during biological post-filtration

Urs von Gunten

Micropollutants (MP) with varying ozone-reactive moieties were spiked to lake water in the influent of a drinking water pilot plant consisting of an ozonation followed by a biological sand filtration. During ozonation, 227 transformation products (OTPs) fr ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Reactions of alpha,beta-Unsaturated Carbonyls with Free Chlorine, Free Bromine, and Combined Chlorine

Urs von Gunten

Chemical disinfectants employed in water and wastewater treatment can produce a variety of transformation products, including carbonyl compounds (e.g., saturated and unsaturated aldehydes and ketones). Experiments conducted under conditions relevant to chl ...

AMER CHEMICAL SOC2021

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