Offene Themen für Bachelorarbeiten
| Analyze PVC nanoplastics in soils |
The analysis of individual nanoplastic particles (<1000nm) is still very difficult because it is very hard to generate spectroscopic data of these tiny particles. The aim of the thesis is to test scanning transmission electron microscopy (SEM) for the analysis. With SEM and an special (EDX) detector it is possible to analyze the elemental composition of a particles. While this might not be enough to differentiate most plastics from natural organic particles, it might be possible to differentiate PVC partciles (because of the special C/Cl ratio). This idea will be tested in cooperation with the Environmental Mineralogy Group. First PVC nanoplastic will be produced in the lab and the methods will be tested. If the identification works, soil samples with assumed high PVC concentrations (e.g. close to a factory) will be sampled, nanoplastics will be extracted and analyzed by SEM/EDX. Please contact Prof. Dr. Moritz Bigalke |
| Plastics in viticulture: input pathways for microplastics to the environment under different vineyard management practices |
Plastic materials are widely used within agricultural practice, causing direct contributions to environmental plastic pollution. Special cultures like vineyards have so far received little attention in plastic research. However, several observations indicate a wide use of plastics in viticulture or the input through mulching materials. Based on literature research, field observations and interviews with viticulturists, possible plastic input pathways into the vineyard should be identified and traced. The aim of the work is to establish a causal chain of the input pathways and to quantify them in comparison between conventional cultivation and biodynamic cultivation practice. Please contact Dr. Collin J. Weber |
| Identification of single flood events within floodplain soils |
Floodplain soils are important geoarchives to access past environmental changes and fluvial system dynamics. Within undisturbed floodplain soils of large rivers, the interpretation of “flood beds” poses the change of a simple and inexpensive method to date those soils and trace the sediment accumulation within the last 100 years. Based on field sampling at the Rhine floodplain (Nature reserve Kühkopf, Hesse) and stratigraphic documentation of the sediment cores a first flood bed interpretation should be established through data correlation to flood data of the upper Rhine. First interpretations will be validated through the analysis of sediments grain size composition, organic matter and total organic carbon contents as well as trace metal (Zn, Cu, Pb) analysis via ICP-MS. The aim of the work is the validation of the field-based flood bed interpretation and relative sediment dating by characterising individual flood beds in relation to changing trace metal depositions over time. Please contact Dr. Collin J. Weber |
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Investigation of the fatty acid profile of different edible oil products |
Different vegetable oil samples may have different fatty acid profiles. The fatty acid profile can be a key to determine the origin of biodiesel, which is made from fatty acids of vegetable oil. You are expected to 1) search fatty acid profiles of different edible oils samples in the literature, 2) investigate methods to analyze fatty acid profile, 3) determine fatty acid profile of different edible oil products, 4) discuss the outcome. Please contact Prof. Dr. Moritz Bigalke and Dr, Kaori Sakaguchi-Söder |
| Soils in environmental education – underestimated possibilities and the development of an educational concept for soil topics |
Soils receive a poor public recognition and attention in contrast to other environmental systems (e.g., oceans). The lack of characteristics like “cuteness” or “beauty” as well as the limited visibility of soils or the emotional connotation to “dirt”, are some reasons for this circumstance. Overall, soils and soil related environmental topics (e.g., soil health, soil degradation) are insufficient considered within environmental education. Several soil profiles in the near surrounding of Darmstadt and in cooperation with the environmental education group of the Hofgut Oberfeld (Lernort Bauernhof), offer the possibility to develop an educational concept for teaching about soil formation, the role of soils in the environment and their importance for humans, as well as soil protection. Based on the available soil profiles, their characterisation and basic soil data a concept should be developed with enables an easy access to soil information for children, young people and adults. The aim of this work is the preparation and presentation of soil data for teaching content in environmental education as well as the creation of an integrated concept for communication. Please contact Prof. Dr. Moritz Bigalke |
| Bodenlehrpfad Darmstadt |
Based on the previous BSc topic about didactic presentation of the soil on the Oberfeld and in the nearby forest, the information can be brought together with the spatial geology information and information about historical and current land use practice to fully understand the soil development. The information can be used to develop a didactic concept about how to connect the different profiles and maybe integrate geomorphology features or rock outcrops to a Bodenlehrpfad (Soil-learning path) with enables an integrated understanding of the soil development in the area. Please contact Prof. Dr. Moritz Bigalke |
Offene Themen für Masterarbeiten
| Micro- and nanoplastic related topics | |
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Tire wear particles in highway roadside soils Starts ASAP |
Tire wear particles (TWP) which arise from the abrasion of vehicle tyres and make up a significant proportion of global microplastic emissions. TWP and allocated pollutants are suspected to cause several consequences for soil environments. A major environmental sink for TWPs are roadside soils along road networks. The aim of this work is the quantification of TWP concentrations and allocated pollutants (e.g., trace metals) in roadside soils from national highways within the Rhine-Main area. The work includes sample preparation, TWP extraction and microscopic methods with image analysis procedures for the characterisation of TWP particle-features. Additional methods like Scanning electron microscope (SEM) or ICP-MS measurements for trace metal analysis are possible. Previous experience in laboratory work and in the programming language R for statistics and data management would be desirable. Please contact Dr. Collin J. Weber |
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Microplastic extraction from forest soils Starts from WiSe 2024/25 |
In contrast to other soil systems worldwide, there is no data on microplastic abundance in forest soils so far. Forest and their soils fulfil important ecosystem functions and are key parts of global material cycles (e.g., carbon-cycle). The complex soil structure and presence of organic layers (L and O-layers) build up from litter in different decomposition states, challenges the extraction of microplastics from forest soils. The aim of this work is the evaluation, testing and improvement of a customised extraction method for microplastics from forest soils. Incubation experiments with self-produced microplastics and forest soil material, wet chemical extraction methods, quality control measurements and µFTIR (chemical imaging) methods will be used. Laboratory experience is required for this work. Please contact Dr. Collin J. Weber |
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Microplastic dynamics in forest soils Starts from SoSe 2025 |
Forests are highly dynamic environmental systems, including complex material cycles and interactions with the atmos-, hydros- and pedosphere. Forest soils have a key role in those material dynamics. However, it is unknown how microplastics are transported to forest soils and within forests. The aim of this work is the implementation of monitoring measures that record the atmospheric deposition of microplastics in forests and their variance in forest soils. Beyond field work and sampling, intensive laboratory work including microplastic extraction and analysis via µFTIR (chemical imaging) methods will be performed. Previous experience in laboratory work and in the programming language R for statistics and data management would be desirable. Please contact Dr. Collin J. Weber |
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The uptake of small microplastics and nanoplastics by plants Starts from October 2023 |
Small microplastics (< ca 10 µm) and nanoplastics (< 1 µm) can be taken up from soils into plants. The uptake can take place at the root surface and is dependent on the soil and plastic properties. The uptake of the plastics can probably affect plant health. If crops are considered the plant uptake of microplastics is a possible way in the human food chain. In this master thesis crops will be grown in soils, which are conditioned with plastics of a defined size, which contain a flourescent label. The size of the particles or the soil type can be varied to assess the effect of these factors on plastic uptake. Soil solution samples will be taken at different times during plant growth and analyzed for plastics to assess plastic availability for plants. The crops will be grown to full maturity and then be harvested. The different plant parts will be analyzed for the presence of plastics in their tissues and the results will be interpreted in terms of uptake and translocation of plastics in crops Please contact Prof. Dr. Moritz Bigalke and Hannah Forsyth |
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Microplastic in agricultural soils Starts from September 2023 |
Agricultural soils are important for the human nutrition but also receive high loads of microplastics. We have a full set of soils with different history of plastic application reaching from mulch foil, to compost and sewage sludge application. The soils can be analysed for its microplastic concentrations and characteristics to understand if different sources cause different MP patterns in agriculture. Please contact Prof. Dr. Moritz Bigalke |
| Trace metal and metal isotpoes related topics | |
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Uranium in peat bodies of the Hessian Ried Starts from WiSe 2024/25 |
Uranium (U) contamination of groundwater has received recent attention globally. Locally, high U concentrations up to about 90 µg L-1 were found in reducing groundwaters close to peat-rich deposits in paleo-meanders of the abandoned course of the river Neckar, the so-called “Bergstraßenneckar”, in the Hessian Ried. These U concentrations greatly exceeded the threshold U concentration in drinking water in Germany of 10 µg L-1. It is hypothesized that the U was initially sorbed to peat and released during the contact with oxygen-rich groundwater. The aim of this work is to determine U concentrations in peat bodies close to groundwater monitoring wells in the Hessian Ried. The work includes field sampling, sample preparation including microwave digestions and sequential extractions in an oxygen-free glovebox. Previous experience in laboratory work and ArcGIS are desirable. Please contact Dr. Kai Nitzsche |
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Mobility of arsenic and heavy metals in floodplain soils of the Usa River Starts from WiSe 2025/26 |
Arsenic (As) is a highly toxic metalloid of global concern. Often, As originates from natural sources such As-bearing iron oxides or As-bearing sulphide minerals in geothermal deposits. Reduction of iron oxides under anoxic conditions and oxidation of sulphide minerals leads to the mobilization of As into groundwater and/or deposition in (flood)plain soils. Changes in redox conditions driven by wet-dry events may mobilize As from such floodplain soils. The city Bad Nauheim is located in a fault zone on the eastern edge of the Taunus. Here, As-bearing hydrothermal alterations are the source of As in (flood)plain soils. Furthermore, untreated wastewaters from thermal water production have contributed to the pollution of floodplain soils by As and other heavy metals such as zinc (Zn). In the first step, As-contaminated floodplain soils will be identified in a field campaign following elemental analysis. Next. flooding experiments will be carried out with As-contaminated floodplain soils of different land use to study the potential mobility of As under changing redox conditions. A sequential extraction (SE) procedure will be carried out to the assess changes in metal partitioning in the soil solid phase. Overall, we expect to gain a better knowledge of the potential mobility of As from floodplain soils due to expected extreme weather conditions that cause flooding and drying. Please contact Dr. Kai Nitzsche |
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Copper particles from brake wear in roadside soils Starts from WiSe 2025/26 |
The new Euro 7 emission standard aims to reduce emissions from tires and brakes into the environment. Brake wear from vehicular traffic is known to be an important source of overall particulate matter (PM) emissions. Brake pads can contain up to 15 % of copper (Cu) in the form of elemental Cu, brass, Cu oxides and Cu sulphides, as well as other toxic elements such as antimony (Sb) posing environmental risks. Yet, little is known about the concentrations and fate of brake wear particles in (road)side soils. The ultimate goal of this study is to develop a method for the separation and identification of Cu particles from brake pads in soils. As a starting point, road dust samples will be used to extract Cu particles using a known extraction method as well as density separation. Bulk samples and extracted particles will be analysed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) as well as the Cu concentrations determined by ICP-MS following digestions. In the second step, the method will be employed to (road)side samples to be collected in the field. Previous experience in laboratory work is desirable. This master thesis is ideally coupled with a Scientific Training. Please contact Dr. Kai Nitzsche |
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Mobility of potentially toxic trace elements in floodplain soils from Biebergemünd Starts from SoSe 2025 |
Historical mining activities have led to the pollution of floodplain soils by potentially toxic trace elements (PTEs) in Biebergemünd, Southeast Hesse. Reducing conditions due to flooding events cause the dissolution of Fe-Mn (oxyhydr)oxides thereby releasing sorbed PTEs including the redox-sensitive, highly toxic metalloid arsenic (As). However, the input of electron acceptors such as N5+ in nitrate, e.g. from agricultural applications, could delay the reduction of Fe-Mn (oxyhydr)oxides by maintaining (sub)oxic conditions. In this master thesis, batch experiments will be conducted in an anoxic glovebox using different nitrate concentrations and contaminated soils (different horizons, locations), and the release of PTEs from the soil will be studied. A sequential extraction (SE) procedure will be carried out to the assess changes in metal partitioning in the solid phase. Please contact Dr. Kai Nitzsche |
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Leaching and sorption of trace metals from and on microplastics Starts from WiSe 2025/26 |
Trace metals as inorganic pollutants, but also micronutrients, and microplastics as polymeric particulate pollutants are both present within soils. Therefore, interactions of both substances are conceivable depending on biogeochemical soil properties. For example, trace metals from the soil matrix could adsorb to plastic particles. However, it is also known that metals and metal compounds are present in plastics (e.g., colour pigments), which could be leached from the plastics in the soil. Those processes have been already studied within marine or aquatic systems, but not for soil systems so far. The aim of this work will be the implementation and conduction of both, leaching and sorption experiments under laboratory conditions with common polymers (PE, PP, PS) and trace metals like copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd). The focus should be on leaching and sorption within soil pore water containing different amounts of polymers and trace metals as well as different water conditions (e.g., pH, carbonate content and dissolved organic carbon). Please contact Dr. Collin J. Weber and Dr. Kai Nitzsche |
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Leaching of trace metals from and sorption of nutrients on tire and road wear particles Starts from WiSe 2025/2026 |
Tire and road wear particles (TRWP) represent a significant part of the microplastics emitted into the environment including agricultural fields. On the one hand, potentially toxic trace elements (PTEs) such as zinc (Zn) can leach from TRWP into soils. On the other hand, important nutrients including ammonium (NH4+) and phosphate (PO43-) can sorb onto the surfaces of TRWP. The leaching and sorption behaviour of TRWP in soils depend on the environmental conditions including the pH and ionic strength. To better understand the leaching of PTEs from and the sorption of nutrients to TRWP, we will perform batch experiments. The focus will be on the leaching and sorption within soil pore water covering different pH values and nutrient concentrations. Leaching and sorption experiments will be performed using unaltered TRWP as well as TRWP that underwent the protocol for regular TRWP extraction from soils to test whether the extraction affects the leaching and sorption behaviour of TRWP. Previous experience in laboratory work is desirable. This master thesis can be coupled with a Scientific Training. Please contact Dr. Kai Nitzsche |
| Special topics | |
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Investigation of hydrogen isotope ratios of rapeseed samples Starts from SoSe 2025 |
Rapeseed oil is one of the major feedstock materials to produce biodiesel. In Germany, rapeseeds are cultivated in the fields of a wide range of soil types. Depending on the soil types, behaviors (e.g.: evaporation) of the water in the soil may differ. As a result, hydrogen isotope ratios of the soil water may differ. When plants take up soil water with different hydrogen isotope ratios, the isotope fingerprint of rapeseed oil may also vary. In the graduation project, you are expected to 1) understand the techniques to determine hydrogen isotope ratio of water and fatty acids of vegetable oil, 2) analyze hydrogen isotope ratios of rapeseed samples cultivated in agricultural fields with different soil properties; 3) determine soil properties, 4) discuss the outcome. Please contact Prof. Dr. Moritz Bigalke and Dr. Kaori Sakaguchi-Söder |
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Water isotopes (δ18O, δD) to estimate water uptake by trees Starts from SoSe 2025 |
Drought and high temperatures have harmed the temperate trees in the forest east of Darmstadt (Darmstädter Stadtwald) over the past years. To better understanding drought stress, it is crucial to knowing the seasonal variation of the water sources to the trees. In this work, stable oxygen and hydrogen isotopes will be determined from soil solutions, soil cores of different depth, local precipitation, and xylem water from trees (beeches) to be collected over the growing season (February to October) 2025 from three plots in the forest east of Darmstadt. Stable oxygen and hydrogen isotopes of local precipitation will be analyzed using cavity ring-down spectroscopy (CRDS) at the IAG together with Dr. Nils Michelsen, while cryogenic extractions will be used to extract water of soil cores and xylem samples together with Dr. Paul Königer at the Federal Institute of for Geosciences and Natural Resources (BGR), Hannover. Previous experience in laboratory work and water stable isotopes is desirable. This master thesis is ideally coupled with a Scientific Training. Please contact Dr. Kai Nitzsche |