Elisabeth Janssen


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Janssen

First Name

Elisabeth

ORCID

0000-0002-5475-6730

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2014 - 201912020 - 20222
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Publications 1 - 3 of 3
  • Environmental Chemistry of Biomolecules
    Item type: Habilitation Thesis
    Janssen, Elisabeth (2022)
    This habilitation thesis entitled “Environmental Chemistry of Biomolecules” focusses on determining chemical information to evaluate water quality and to protect human health and ecosystem functioning. Such knowledge is crucial for public authorities to manage water resources especially as we are facing growing inputs of bioactive chemicals with adverse environmental effects. My work is rooted in environmental and analytical chemistry of aquatic enzymes, natural toxins, and micropollutants. I investigate the environmental behavior of these molecules to define the exposure side of human and ecological risk assessment. My team has built an expertise for analytical solutions to study site-specific damage of biomolecules of varied complexity. My aim is to elucidate how long-lived these biomolecules are in environmental and engineered systems. Therefore, we study transformation processes with a particular focus on photochemical and enzymatic reactions. Presented is a cumulative thesis in accordance with the current regulation in the Department of Environmental Systems Science at ETH Zürich. The thesis is structured in three parts: In chapter 1, I highlight the impact of daylight on the environmental chemistry of biomolecules emphasizing some of my contributions. In chapter 2-5, I present detailed studies of each focus area: photochemical transformation of micropollutants (chapter 2), photochemical transformation of enzymes and their building blocks (chapter 3), diversity of bioactive and toxic biomolecules from cyanobacteria (chapter 4), and production dynamics and environmental fate processes of natural products (chapter 5). At the beginning of each chapter, you find a brief overview followed by the individual studies. In chapter 6, I highlight new avenues of my current and future research on the environmental chemistry of cyanobacterial toxins. Chapter 1 and chapter 6 are original parts of this habitation thesis that have not previously been published.
  • Reactivity of dissolved organic matter towards direct and indirect photochemistry of pollutants and biomolecules
    Item type: Other Conference Item
    Janssen, Elisabeth; Erickson, Paul R.; McNeill, Kristopher (2014)
    Abstracts of Papers of the American Chemical Society
  • Chlorothalonil transformation products in drinking water resources: Widespread and challenging to abate
    Item type: Journal Article
    Kiefer, Karin; Bader, Tobias; Minas, Nora; et al. (2020)
    Water Research
    © 2020 The Authors Chlorothalonil, a fungicide applied for decades worldwide, has recently been banned in the European Union (EU) and Switzerland due to its carcinogenicity and the presence of potentially toxic transformation products (TPs) in groundwater. The spread and concentration range of chlorothalonil TPs in different drinking water resources was examined (73 groundwater and four surface water samples mainly from Switzerland). The chlorothalonil sulfonic acid TPs (R471811, R419492, R417888) occurred more frequently and at higher concentrations (detected in 65–100% of the samples, ≤2200 ngL−1) than the phenolic TPs (SYN507900, SYN548580, R611968; detected in 10–30% of the samples, ≤130 ngL−1). The TP R471811 was found in all samples and even in 52% of the samples above 100 ngL−1, the drinking water standard in Switzerland and other European countries. Therefore, the abatement of chlorothalonil TPs was investigated in laboratory and pilot-scale experiments and along the treatment train of various water works, comprising aquifer recharge, UV disinfection, ozonation, advanced oxidation processes (AOPs), activated carbon treatment, and reverse osmosis. The phenolic TPs can be abated during ozonation (second order rate constant kO3 ∼104 M−1s−1) and by reaction with hydroxyl radicals ([rad]OH) in AOPs (kOH ∼109 M−1s−1). In contrast, the sulfonic acid TPs, which occurred in higher concentrations in drinking water resources, react only very slowly with ozone (kO3 <0.04 M−1s−1) and [rad]OH (kOH <5.0 × 107 M−1s−1) and therefore persist in ozonation and [rad]OH-based AOPs. Activated carbon retained the very polar TP R471811 only up to a specific throughput of 25 m3kg-1 (20% breakthrough), similarly to the X-ray contrast agent diatrizoic acid. Reverse osmosis was capable of removing all chlorothalonil TPs by ≥98%.
Publications 1 - 3 of 3