Publications related to Hypochlorite

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

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

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

Chlorination of Phenols Revisited: Unexpected Formation of α,β-Unsaturated C4-Dicarbonyl Ring Cleavage Products

Urs von Gunten

Despite decades of research on the fate of phenolic compounds when water is disinfected with hypochlorous acid (HOCl), there is still considerable uncertainty regarding the formation mechanisms and identity of ring cleavage products, especially at higher c ...

2020

Force microscopy of the Caenorhabditis elegans embryonic eggshell

Martinus Gijs, Thomas Lehnert, Roger Philippe Krenger

Assays focusing on emerging biological phenomena in an animal's life can be performed during embryogenesis. While the embryo of Caenorhabditis elegans has been extensively studied, its biomechanical properties are largely unknown. Here, we demonstrate that ...

NATURE PUBLISHING GROUP2020

Solar-Electrochemical Platforms for Sodium Hypochlorite Generation in Developing Countries

Demetri Psaltis, Christophe Moser, Seyyed Mohammad Hosseini Hashemi, Enrico Chinello

On-site generation of sodium hypochlorite (NaClO) holds the potential to bring an efficient and cost-effective water disinfection method to isolated and remote locations. Solar-driven, stand-alone reactors could provide those communities full independence ...

ELECTROCHEMICAL SOC INC2019

Solar-Electrochemical Devices for Water Splitting and Chlorine Generation

Enrico Chinello

Solar technologies hold the potential to ultimately counteract the effects of climate change. Nevertheless, the intermittency of sunlight poses technical challenges regarding the storage of the surplus production and the supply of the deficit. The generat ...

EPFL2019

In Situ Formation of Free Chlorine During ClO2 Treatment: Implications on the Formation of Disinfection Byproducts

Urs von Gunten

Chlorine dioxide (ClO2) is commonly used as an alternative disinfectant to chlorine in drinking water treatment because it produces limited concentrations of halogenated organic disinfection byproducts. During drinking water treatment, the primary ClO2 byp ...

AMER CHEMICAL SOC2018

The Chaperone and Redox Properties of CnoX Chaperedoxins Are Tailored to the Proteostatic Needs of Bacterial Species

Camille Véronique Bernadette Goemans

Hypochlorous acid (bleach), an oxidizing compound produced by neutrophils, turns the Escherichia coli chaperedoxin CnoX into a powerful holdase protecting its substrates from bleach-induced aggregation. CnoX is well conserved in bacteria, even in non-infec ...

2018

Impact of Combined Chlorination and Chloramination Conditions on N-Nitrosodimethylamine Formation

Urs von Gunten

Bench-scale chloramination under uniform formation conditions was used to examine N-nitrosodimethylamine (NDMA) formation in settled and (bio)filtered drinking water and treated wastewater. In this study, water temperature, pH, postchloramination time, and ...

WILEY2018

A bimetallic nanocoral Au decorated with Pt nanoflowers (bio)sensor for H2O2 detection at low potential

Giovanni De Micheli, Sandro Carrara, Irene Taurino, Francesca Puppo

In this work, we have developed for the first time a method to make novel gold and platinum hybrid bimetallic nanostructures differing in shape and size. Au-Pt nanostructures were prepared by electrodeposition in two simple steps. The first step consists o ...

Academic Press Inc Elsevier Science2017

Study of Hypochlorite Reduction Related to the Sodium Chlorate Process

Michael Markus Busch

Reduction of hypochlorite is the most important side reaction in the sodium chlorate reactor leading to high energy losses. Today chromate is added to the reactor solution to minimize the hypochlorite reduction but a replacement is necessary due to health ...

Springer2016

Chemical Oxidation of Dissolved Organic Matter by Chlorine Dioxide, Chlorine, And Ozone: Effects on Its Optical and Antioxidant Properties

Urs von Gunten, Silvio Canonica

In water treatment dissolved organic matter (DOM) is typically the major sink for chemical oxidants. The resulting changes in DOM, such as its optical properties have been measured to follow the oxidation processes. However, such measurements contain only ...

Amer Chemical Soc2013

Effects of carbonate on the electrolytic removal of ammonia and urea from urine with thermally prepared IrO2 electrodes

Christos Comninellis, Agnieszka Kapalka, Véronique Amstutz, Kai Udert

Recent studies have shown that electrolysis can be an efficient process for nitrogen removal from urine. These studies have been conducted with urea solutions or fresh urine, but urine collected in NoMix toilets and urinals has a substantially different co ...

Springer Netherlands2012

Mechanistic studies on two dinuclear organogold(III) compounds showing appreciable antiproliferative properties and a high redox stability

Angela Casini

Two dinuclear oxo-bridged organogold(III) compounds, namely [(N,N,C)(2)Au-2(mu-O)]PF6 (with N,N,CH = 6-(1-methylbenzyl)-2,2'-bipyridine, Au(2)O1; or 6-(1,1-dimethylbenzyl)-2,2'-bipyridine, Au(2)O2), were previously prepared and characterised. Their so ...

2011

Sequential ATRA-Reductive Cyclopropanation Reactions with a Ruthenium Catalyst in the Presence of Manganese

Kay Severin, Charlotte Buron

Atom-transfer radical addition (ATRA) reactions of ethyl trichloroacetate, dichloromalononitrile, or diethyl 2,2-dichloromalonate with olefins followed by dechlorination have provided functionalized cyclopropanes in one step. The RuIII complex [Cp*RuCl2(PP ...

Wiley-Blackwell2011

Heterogeneous Chemistry of Cl2O and HOCl on Frozen Natural Sea Salt, Recrystallized Sea Salt, KCl and NaCl Solutions at 200 and 215 K

Michel Rossi, Pascal Pratte

The HOCl heterogeneous reaction on frozen natural (NSS) and recrystallized (RSS) sea salt KCl and NaCl solutions was studied using a low pressure flow reactor in order to measure the uptake coefficient gamma and products of reaction The HOCl sample used in ...

Oldenbourg Wissenschaftsverlag GmbH, De Gruyter2010

Cinétique de réaction hétérogène d'importance troposphérique sur des substrats modèles et sur des aérosols

Pascal Pratte

The first part of this study consists in the investigation of the evaporation and the condensation rate of H2O in the presence of different types of ice in a low pressure flow reactor. The second part of the present work reports the study of chlorine activ ...

EPFL2006