Department Environmental Chemistry

Master thesis topics 2018

Fate in Technical Systems

Contaminant fate processes

Characterising the Anthropogenic Impact on Groundwater by Performing a Target Screening for Organic Micropollutants

Groundwater contributes to 80% of drinking water supply in Switzerland, explaining the high concerns for its quality. Various contaminant sources such as manure and pesticide application in agriculture, leachate from sewer systems, landfills, or industrial sites, and the infiltration of possibly contaminated surface waters either naturally or via managed aquifer recharge pose risks to groundwater bodies.

This master thesis is embedded in the project "Suspect and Non-target Screening of Organic Micropollutants in Swiss Groundwaters". The aim is to characterise and quantify the micropollution fingerprint in aquifers in catchments with different landuse. For this, 60 samples have been collected and analyzed with liquid chromatography coupled by electrospray ionization to high resolution tandem mass spectrometry (LC-ESI-HRMS/MS). Using the dataset, more than 100 organic micropollutants will be quantified resulting in a micropollutant fingerprint for each aquifer. The micropollutant contamination will then be explained and discussed by taking into account the substance properties and the hydrogeological settings, e.g., landuse in catchment, soil permeability, and infiltrating river water.

For this thesis a background in environmental sciences, geoecology or related fields as well as interest in the analysis of organic micropollutants with LC-ESI-HRMS is necessary. Basic hydrological / hydrogeological system understanding and French / German language skills to eventually communicate with people from the cantons may be advantageous.

Starting Date: November / December 2018

Advisors: Karin Kiefer, Prof. Juliane Hollender

Contact: karin.kiefer@eawag.ch, Tel. +41 58 765 5087

Webpage https://www.eawag.ch/en/department/uchem/projects/suspect-and-non-target-screening-of-organic-micropollutants-in-swiss-groundwaters/

Fate of Natural Toxins in surface waters

Assessing the environmental transformation processes of cyanotoxins – Focus: Phototransformation and/or biotransformation, time series experiments, quantification of transformation kinetics, LC-MS analytics
Contact: Elisabeth Janssen

Application of a suspect screening workflow on passive sampler extracts to identify biotransformation products formed in the hyporheic zone

keywords:  analysis of LC-HRMS data, organic pollutants, suspect   screening, elucidation of hyporheic (bio)transformation   products, sediment concentration profiles

Contact: Juliane Hollender

Water quality and management

Identification of Natural Toxins using High Resolution Mass Spectrometry

Assessing production dynamics of cyanopeptides from bacterial cultures and toxin profiles in samples from harmful algae blooms – Focus: batch culturing setups of cyanobacteria, sample preparation steps with final analysis by LC-MS.
Contact: Elisabeth Janssen

  

Pesticide input into Swiss surface waters

Combining Information on Possible Sources of Pesticide Losses

Micropollutants are a challenge for surface water protection. The Swiss cantons and the Federal Office of the Environment (FOEN) are currently expanding the routine monitoring of surface waters. In a special evaluation of the situation in small streams pesticide concentrations were measured with high time resolution and advanced analytical methods which cover the majority of currently used pesticides (NAWA Spez-Program). Such evaluations are a valuable source to increase the understanding how pesticides reach surface water.

The thesis will be based on the measurements of one of the five NAWA Spez catchments. The goal of the thesis is to use these data to better understand which areas contribute most to elevated concentrations in the catchment. This shall be achieved by existing georeferenced data (e.g., erosion risk maps,  surface water access) with data on pesticide usage on the different areas of the catchment.

Further evaluations shall show to which degree these information can be used to identify the processes causing the pesticide losses, e.g. surface run-off from fields to streams or loss via drained soils. Such insights are highly valuable for developing effective measures to reduce pesticide losses to surface waters. The work will be developed in collaboration with cantonal project leaders. Knowledge on GIS would be an advantage. Supervision and workplace will be provided by eawag.

Keywords: diffuse pollution, geographical information systems, hydrology and transport  

Contact: Christian Stamm

Pesticide pollution in a tropical catchment in Costa Rica

keywords: diffuse pollution, statistical analysis, hydrology and transport

Contact: Christian Stamm

Analytics

Development of sensitive method for the quantification of emerging contaminants in surface water samples using a novel coupling technique GC-DBDI-Orbitrap

Contact: Heinz Singer

Detection of drug conjugates in waste water by high resolution mass spectrometry using post-acquisition neutral scan experiments

Contact: Heinz Singer

Identification of organic contaminants in the wastewater of chemical industries using high resolution mass spectrometry

keywords:   industrial wastewater, surface water contamination, analytical   chemistry, non-target screening, time series analysis

Contact: Heinz Singer

Environmental Fate Modeling

Investigating the effects of cytochrome P450 inhibitors on the biotransformation of organic micropollutants in activated sludge

keywords:   biotransformation experiments, activated sludge, LC-MS   measurements of organic micropollutants

Contact: Kathrin Fenner

Stable Isotope Lab

Assessing the biotransformation of hexachlorocyclohexane isomers in contaminated soil

Abstract:

Hexachlorocyclohexanes (HCH), such as the insecticidal gamma-HCH isomer, belong to the class of largely banned persistent organic pollutants (POP). Because HCHs only degrade over time-scales of decades and more, they are still found to contaminate soils at former production sites. In our research, we develop new approaches to track biodegradation processes based on the stable isotope fractionation that can be measured in the remaining pollutant.

In this project, we aim at understanding the C and H isotope effects pertinent to the different enzymatic dechlorination mechanisms of several HCH isomers. Candidates will learn (1) how to purify and work with LinA and LinB enzymes that are capable of transforming HCH isomers into less chlorinated compounds as well as (2) how to carry out compound-specific stable isotope analysis of H and C using gas chromatographs coupled to isotope ratio mass spectrometers.

Contact: Thomas Hofstetter

Compound-specific stable isotope analysis of insensitive munitions

Abstract:

Insensitive munitions explosives such as dinitroanisole and nitrotriazolone are new formulations that are safer to handle and transport, with less risk of self-detonation, than traditional nitroaromatic and nitramine explosives (e.g., trinitrotoluene, TNT). However, these new compounds are more water soluble and more mobile in the environment and their (bio)degradation pathways are understood only poorly.

In this work, we aim to develop new analytical tools for the measurement of carbon, nitrogen, and hydrogen isotope ratios of insensitive munitions. Isotopic fingerprints and isotope fractionation of these frequent soil and groundwater contaminants will be used to identify contamination sources and degradation pathways.

Contact: Thomas Hofstetter

Bioavailability of structural iron in smectites

Abstract:

Iron-bearing clay minerals are important redox buffers in the subsurface that can affect the biogeochemical cycling of elements and the fate, transport, and toxicity of pollutants. To assess the role that structural Fe in clay minerals plays in redox reactions in pristine and contaminated environments, we have recently developed electrochemistry-based approaches to derive thermodynamic parameters of such mineral phases.

In this work, we explore whether the activity of iron-reducing bacteria (Shewanella and Geobacter species) is controlled by the thermodynamic properties of the mineral specimen. Students will have the opportunity to combine their knowledge on biogeochemistry and thermodynamics with new experience in electrochemical analyses.

Contact: Thomas Hofstetter