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Here, we describe a fast and simple extraction method for the determination of per- and polyfluorinated alkyl substances (PFASs) utilizing extractable organic fluorine (EOF) sum parameter analysis and high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) in soil samples. After extraction and separation of inorganic and organic fluorinated compounds, organically bound fluorinated compounds were indirectly determined via the molecular absorption of gallium mono-fluoride at 211.248 nm. The implementation of the decisions of the “Stockholm Convention on persistent organic pollutants” as well as the “Protocol on Persistent Organic Pollutants of the Convention on Long-Range Transboundary Air Pollution” of the UNECE include the reduction respectively the elimination of PFASs in the environment. Currently, regulations aim to target single compounds (mostly C8-PFAS). But the PFAS group includes over 4700 substances, which are potentially persistent and toxic, thus target analytical approaches are not suitable for a holistic approach investigating the PFAS pollutant situation. Furthermore, forbidden PFASs are substituted by short-chain PFASs, thus the number of unknow substances is steadily increasing. For this reason, sum parameter approaches are more suitable to investigate and assess the pollution situation as well as derive exposure limits. Our developed analytical method was successfully applied to determine PFASs in soil samples from a polluted site. In view of steadily increasing numbers of PFAS substances, our method will make an important contribution in assessing the pollution situation as well as support policy makers in deriving exposure limits for PFAS in the future.
The development of offshore wind turbines (WTGs) presents many challenges in terms of safe operation over extended periods of time. One of these is the corrosive environment towards metallic materials, which can lead to a loss of material thickness and thus to a deterioration of mechanical performances, especially the strength of infrastructures. This can be counteracted by painting and cathodic protection (CP). Much research has already been done in this area about inhibiting the corrosion process. However, gaps exist regarding free corrosion. This plays a greater role especially for time intervals during the installation of the systems and their maintenance, during which often no CP can be operated. This is especially true for areas where painting surfaces is impossible e.g., sediment areas. This problem is exacerbated by the different corrosion rates caused by the different zones (water and sediment), with their different amounts of dissolved oxygen.
This presentation deals with experiments in artificial seawater and sediment. Classical S355J2 steel samples in the form of coupons were fitted with welding wires that carried out the electrical contact to the outer side of the basin. Inside the basins, the specimens are stored in different zones like water and sediment which should simulate the foundation situation of monopiles. The mass loss was determined gravimetrically, elemental currents between specimens in water and sediment were measured and electrochemical investigations were carried out. The influences of the zones, based on different solved oxygen contents, and the rolling skin towards the corrosion behavior of the mild steel samples were determined in this work. Especially the influence of the sediment showed unexpected behavior, determined by electrochemical investigations. These results allow better conclusions to be drawn about the corrosion behavior of low alloy steels in offshore environments used in sediment and seawater, which cannot always be protected.
Organotin compounds (OTCs) have been widely used in anti-fouling paints, pesticide formulations, and as stabilizers in polyvinyl chloride over the past century. In marine ecosystems, OTCs can cause severe damage to biodiversity, leading up to the extinction of vulnerable species. Due to the extensive use of tributyltin (TBT) as a biocide on ship hulls, it has been considered one of the most hazardous substances intentionally introduced into the aquatic environment. This resulted in a global ban on TBT-containing products in the 2000s. However, recent studies indicate the emerging presence of organotin pollutants.
OTCs are known to persist and accumulate in marine sediments, posing a long-term threat to the environment. These harmful substances can be set free and dispersed even after several decades. Therefore, analyzing sediment probes is imperative for a thorough monitoring of pollution. However, species-specific analysis of OTCs at required concentration levels in complex environmental matrices remains challenging. Chromatographic systems are commonly used for their analysis, but the required sample preparation is time-consuming and prone to contamination and analyte loss. The coupling of electrothermal vaporization and inductively coupled plasma-mass spectrometry (ETV/ICP-MS) demonstrates high potential as a rapid, convenient, and chemical-saving scanning tool for environmental samples.
This method enables the direct on-line fractionation of organic compounds from an inorganic fraction and provides element-specific detection at ultra-trace levels without complex sample preparation. Since OTCs are generally more toxic than ionic or elemental tin, analyzing them as a sum parameter is advantageous. Additionally, the determination of both organic and inorganic tin, rather than just organic tin, reveals valuable information about the fate of OTCs. The main challenge in obtaining accurate quantitative data using direct solid sampling techniques like as ETV/ICP-MS is applying a suitable calibration strategy. Our isotope dilution approach overcomes matrix effects in ETV/ICP-MS analysis and is compatible with commercial systems.