Publications related to Ozonation of Para-Substituted Phenolic Compounds Yields p-Benzoquinones, Other Cyclic α,β-Unsaturated Ketones, and Substituted Catechols

Oxidation processes and me

This publication summarizes my journey in the field of chemical oxidation processes for water treatment over the last 30+ years. Initially, the efficiency of the application of chemical oxidants for micropollutant abatement was assessed by the abatement of ...

Pergamon-Elsevier Science Ltd2024

The Mn(VII)-H2O2 oxidation process: Abatement of electron-deficient N-containing organic compounds

Urs von Gunten, Ke Xu

Chemical oxidants applied in water treatment are electrophiles, which preferentially attack sites with higher electron density. This typically results in less efficient oxidative abatement of organic compounds with electronwithdrawing substituents. In this ...

Elsevier Science Sa2024

Reactivity of Cyanobacteria Metabolites with Ozone: Multicompound Competition Kinetics

Urs von Gunten

Cyanobacterial blooms occur at increasing frequency and intensity, notably in freshwater. This leads to the introduction of complex mixtures of their products, i.e., cyano-metabolites, to drinking water treatment plants. To assess the fate of cyano-metabol ...

Amer Chemical Soc2024

Treeline displacement may affect lake dissolved organic matter processing at high latitudes and altitudes

Hannes Markus Peter

Climate change induced shifts in treeline position, both towards higher altitudes and latitudes induce changes in soil organic matter. Eventually, soil organic matter is transported to alpine and subarctic lakes with yet unknown consequences for dissolved ...

Nature Portfolio2024

In Situ Synthesis of CuxO/N Doped Graphdiyne with Pyridine N Configuration for Ammonia Production via Nitrate Reduction

Sophia Haussener, Roberto Valenza, Jian Li

Electroreduction of nitrate to ammonia provides an interesting pathway for wastewater treatment and valorization. Cu-based catalysts are active for the conversion of NO3− to NO2− but suffer from an inefficient hydrogenation process of NO2−. Herein, CuxO/N- ...

2024

Monitoring an Emergent Pathogen at Low Incidence in Wastewater Using qPCR: Mpox in Switzerland

Tamar Kohn, Timothy R. Julian

Wastewater-based epidemiology offers a complementary approach to clinical case-based surveillance of emergent diseases and can help identify regions with infected people to prioritize clinical surveillance strategies. However, tracking emergent diseases in ...

2024

Organic matters, but inorganic matters too: column examination of elevated mercury sorption on low organic matter aquifer material using concentrations and stable isotope ratios

Lorenz Schwab

Sorption of mercury (Hg) in soils is suggested to be predominantly associated with organic matter (OM). However, there is a growing collection of research that suggests that clay minerals and oxides are also important solid phases for the sorption of solu ...

2024

Adsorption of Copper by Naturally and Artificially Aged Polystyrene Microplastics and Subsequent Release in Simulated Gastrointestinal Fluid

Florian Frédéric Vincent Breider, Thibault Béranger Masset, Lu Zhou

Microplastics, especially aged microplastics can become vectors of metals from environment to organisms with potential negative effects on food chain. However, a few studies focused on the bioavailability of adsorbed metals and most studies related to aged ...

2024

New Applications of 1,3,2-Diazaphospholenes in Catalysis

Johannes Klett

The constant urge to construct new molecules in an economical and sustainable fashion led to the development of numerous metal-catalyzed transformations. Organocatalysts consisting of abundant and more sustainable elements offer an elegant solution to over ...

EPFL2024

Photo-Fenton inactivation of MS2 bacteriophage at alkaline pH by Fe salts or nm to μm-sized oxides, and the Janus-faced effects of natural organic matter in surface waters

César Pulgarin, Stefanos Giannakis, Ogadimma Cassandra Oji-Okoro, Giulio Farinelli

In this study, MS2 bacteriophage was inactivated by homogeneous and heterogeneous photo-Fenton processes in an alkaline matrix (pH 8) using low concentrations of H2O2 and iron forms (1 mg/L), including Fe(II), Fe(III), and Fe (hydr)oxides. As a reference, ...

Elsevier2024

Mechanistic insights on interactions of dissolved organic matter with chemical oxidants: quantification of reactive sites and identification of oxidation byproducts

Joanna Maria Houska

Chemical oxidants including ozone (O3), chlorine (HOCl/OCl-) and chlorine dioxide (ClO2) are applied for disinfection of drinking water. To cope with water scarcity and the increased risks associated with the presence of micropollutants, water treatment sy ...

EPFL2023

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

Chlorination of amides: Kinetics and mechanisms of formation of N-chloramides and their reactions with phenolic compounds

Urs von Gunten, Tianqi Zhang

Amides are common constituents in natural organic matter and synthetic chemicals. In this study, we investi-gated kinetics and mechanisms of the reactions of chlorine with seven amides, including acetamide, N-meth-ylformamide, N-methylacetamide, benzamide, ...

2023

Oxidative Water Treatment: The Track Ahead

Urs von Gunten, Yun Ho Lee

Chemical oxidation has been applied in municipal water treatment for more than a century, initially for disinfection. In the early decades, chlorine disinfection was adopted in the fight against waterborne disease. However, the oxidative properties of chlo ...

2023

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

Urs von Gunten

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

Formation of carbonyl compounds during ozonation of lake water and wastewater: Development of a non-target screening method and quantification of target compounds

Urs von Gunten, Joanna Maria Houska

Ozonation of natural waters is typically associated with the formation of carbonyl compounds (aldehydes, ketones and ketoacids), a main class of organic disinfection byproducts (DBPs). However, the detection of carbonyl compounds in water and wastewater is ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Ozonation of lake water and wastewater: Identification of carbonous and nitrogenous carbonyl-containing oxidation byproducts by non-target screening

Urs von Gunten, Joanna Maria Houska

Ozonation of drinking water and wastewater is accompanied by the formation of disinfection byproducts (DBPs) such as low molecular weight aldehydes and ketones from the reactions of ozone with dissolved organic matter (DOM). By applying a recently develope ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Evaluation of the role of superoxide radical as chain carrier for the formation of hydroxyl radical during ozonation

Gang Yu, Urs von Gunten, Yan Wang

Superoxide radicals (O-2(center dot-)) have been suggested as an important chain carrier in the radical chain reaction that promotes ozone (O-3) decomposition to hydroxyl radicals ((OH)-O-center dot) during ozonation. However, due to the difficulty in meas ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Predicting Transformation Products during Aqueous Oxidation Processes: Current State and Outlook

Urs von Gunten

Water quality and its impacts on human and ecosystem health presents tremendous global challenges. While oxidative water treatment can solve many of these problems related to hygiene and micropollutants, identifying and predicting transformation products f ...

2023

Why five decades of massive research on heterogeneous photocatalysis, especially on TiO2, has not yet driven to water disinfection and detoxification applications? Critical review of drawbacks and challenges

César Pulgarin, Julian Andrés Rengifo Herrera

For fifty years, heterogeneous photocatalysis has been considered as having potential to remove organic and microbiological pollutants from water under either artificial UV light or sunlight irradiation. However, after tens of thousands of published resear ...

Elsevier Science Sa2023