Evaluation and development of passive sampling techniques on the basis of sediment samples from the Baltic and North Seas

• Evaluierung und Entwicklung von passiven Probenahmetechniken auf der Grundlage von Sedimentproben aus der Ostsee und Nordsee

Reininghaus, Mathias; Schäffer, Andreas (Thesis advisor); Witt, Gesine (Thesis advisor); Schüttrumpf, Holger (Thesis advisor)

Aachen : RWTH Aachen University (2023)
Dissertation / PhD Thesis

Dissertation, RWTH Aachen University, 2023

Abstract

During the course of industrialization and within the decades that followed, countless chemicals were and continue to be released into the environment whose effects, pathways and fate are largely unknown. The aftercare necessitated by this nonchalant approach continues to reveal a large number of these chemicals in numerous environmental compartments decades after their release into the environment. Chemicals tend to accumulate where their chemical-physical properties favor. Hydrophobic organic chemicals (HOCs) are ubiquitously distributed, but prefer to bind to particles and thus, when considering the aquatic environment, are accumulating within the sediment. In the sediment, these contaminants then either bind to the organic particles or partially dissolve in the pore water. Both the part of the pollutants that is in the pore water and the part of the pollutants that remains bound to particles can be detected and quantified by modern measurement methods. Particularly the freely dissolved fraction of the HOCs poses a risk to organisms that have contact with the sediment, albeit in an indirect way. This freely dissolved fraction or freely dissolved concentration (Cfree) has been investigated in detail within the present study through numerous surface sediments and additional sediment cores. In order to determine the freely dissolved concentration of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in sediments, solid phase microextraction (SPME) was used. This passive sampling method, using known partition coefficients, allows the determination of concentrations of contaminants in sediment pore water. Freely dissolved concentrations (Cfree) of PAHs and PCBs were determined (i) in sediment cores from the Baltic Sea (Kattegat) and the Skagerrak, (ii) in surface sediments along the German Baltic Sea coast, (iii) in surface sediments from the North Sea (German EEZ and Wadden Sea), (iv) in surface sediments from various canals between Germany and France (Paris) including numerous samples from the Rhine, and (v) in surface sediments from the Darss-Zingst Bodden chain. The sediments were examined in the laboratory (ex-situ) and, if possible, in the field (in-situ). A detailed comparison of the two methods identified their respective advantages and disadvantages. In addition, supplementary parameters were determined on certain samples and the concentrations of PAHs and PCBs in the total sediment (Ctotal) were determined for multiple sediments. The data acquired through these measurements and the endpoints calculated from them provide an unprecedented comprehensive overview of the sediment contamination situation along the German coast of the North Sea and Baltic Sea and furthermore for numerous stretches of water between Germany and France. Using these data, contamination hotspots and variations could be identified and the HOC`s contribution to the total toxic potential of the sediments could be presented. Ultimately, to further advance the use of this prospective passive sampling method, additional partition coefficients for alkylated PAHs were determined enabling the measurement of these important pollutants via SPME.

Institutions

• Department of Biology [160000]
• Chair of Environmental Biology and Chemodynamics [162710]