Examensarbeten

Examensarbeten har länge varit ett bra sätt att knyta an forskningsverksamheten vid högskolorna till verksamheten vid de kommunala VA-bolagen.

Vid lärosätena i Mälardalsklustret utförs årligen ca 20 examensarbeten inom VA och dessa berör i princip alla områden inom VA-sektorn. Några exempel är framtidens VA-system, kväve- och fosforrening, biogas, reglerteknik med tillämpning mot avloppsvattenrening, miljösystemanalys och VA och sanitet i låginkomstländer. Många studenter utför examensarbeten i samarbete med reningsverken i klustret.

Aktuella examensarbeten

I listan nedan visas de exjobb som för närvarande annonseras av medlemsorganisationerna. Observera att listan uppdateras månatligen eller vid behov.

Listan uppdaterades senast 2022-12-23.

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Hybrid modelling of sand filters at Käppala WWTP (30 hp)

Background: Käppala WWTP is undergoing major changes due to a new environmental permit, stipulating stricter effluent requirements. New process solutions will be implemented in part of the WWTP requiring a long period of reconstruction with treatment lines out of commission, decreasing the total capacity and reducing margins for error in the treatment process. At the same time the existing treatment must be optimized to maximize treatment capacity, to make more use of what is available.

At Käppala WWTP the tertiary treatment, reduction of suspended solids and phosphorous, is conducted in down stream, dual media sand filters. The sand filters are very important in determining the maximum flow through the biological treatment and must function as best as possible at all times. Previous research and development work at Käppala WWTP has identified improvement of the automatic control of the sand filters as a possible measure for increased capacity. Due to the ongoing reconstruction project and the reduced margins of error, testing and implementing improvements of the control system online is difficult.

By utilizing a digital twin connected to the control system improvements can be tested and evaluated prior to being implemented, thus reducing risk of disturbances.

Tasks:

Since modelling of sand filters is not previously explored the main objective of this project is to:

1. Preform a literature review of possibilities and threats in utilizing digital twins for optimization
2. Building a hybrid model för the sand filter treatment stage. It is predicted the model will consist of hydraulic models for inflow and effluent as well as an AI model for the sand filters.
3. Verify the models
4. Investigate suggestions for optimization of the control of sand filters
5. Report results

The result, hybrid model and conclusions, from the thesis will be used in the second part of the project where the hybrid model will be connected to the control system at Käppala WWTP using SIMIT.

Organizations: Käppalaförbundet, IVL. The student will be engaged by Käppalaförbundet. The thesis will be a part of the ongoing project “Industridoktorand Digital Tvilling”, a collaboration between Käppalaförbundet, SYVAB, Stockholm vatten och avfall, IVL, Uppsala university and Lund university.

Contact: Hanna Molin (IVL), hanna.molin@ivl.se; Sofia Bramstedt (Käppalaförbundet), sofia.bramstedt@kappala.se

More information: Here Pdf, 112.2 kB, öppnas i nytt fönster. (Pdf, 112.2 kB).

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Anammox performance in the biochar-based system for Nitrogen removal (30 hp)

Background: Recently, anaerobic ammonium oxidation (anammox) bacteria have been applied for biological nitrogen removal from wastewater. Several studies reported that biochar is an inexpensive redox-active carbon material that has been demonstrated to enhance microbial nitrogen transforming processes (Wang et al., 2022; Xu et al., 2022, 2020). Since anammox is a nitrogen-focused activity, it could be implemented in part of our pilot-scale biochar-based treatment. This study will investigate the potential of anammox bacteria for use in the biochar filter by conducting lab-scale batch experiments.

Research question: What is the performance of biochar as a carrier of the anammox bacteria in lab-scale batch experiments?

Method: Laboratory batch experiments will be conducted by setting up two duplicate reactors. R1-1 and R1-2 contain biochar and anammox bacteria, and R2-1 and R2-2 contain only biochar as a control. Both R1 and R2 will have duplicate conditions. Different concentrations of Nitrogen (mg/L) will be investigated (70-400mg/L). Also, the temperature will be varied between 20 to 37 C. Testing nitrogen removal in reject water might be planned as well since reject water has a high nitrogen concentration. The reactor will run for two months, and NH4, NO2, NO3, COD, and Total nitrogen will be analyzed. The previous study conducted a similar experiment and showed anammox's higher performance with biochar (Mojiri et al., 2020).

Organizations: Uppsala universitet

Contact: Sahar Dalahmeh. sahar.dalahmeh@geo.uu.se; Makoto Shigei makoto.shigei@geo.uu.se

More information: Here Pdf, 112.6 kB, öppnas i nytt fönster. (Pdf, 112.6 kB).

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Artificial intelligence and aquaphotomics for real-time measurement of water quality for optimal operation of wastewater treatment plants (WWTPs) and sustainable use of resources in a circular economy (30 hp)

Background: Wastewater treatment plants show considerable interest in improving process control and performance optimization to move towards more environmentally sustainable production. Contaminants of Emerging Concerns (CECs), such as pharmaceuticals in wastewater, are critical because of their potentially harmful impacts on environmental resources and exposure to humans and biota. While many of the CECs have been present in the environment for decades, the rising concern is driven by the importance of analytical techniques that can detect them rapidly and at low concentrations.

Today, there is a need to establish a protocol for detecting these CECs in wastewater and sludge. Analysis of CEC in wastewater may be challenging, dealing with various particle sizes, structures, shapes, and polymer types dispersed in complex environmental matrices. However, due to the increased presence of CECs in the environment, it is essential to evaluate these analytical techniques.

Content: The proposed project aims to enable real-time characterization of wastewater properties by soft sensors with the help of artificial intelligence (AI) and machine learning algorithms and data from optical sensors, including NIR and UV-Vis spectrometers. Furthermore, a method called aquaphotomics will be considered in the method development https://www.aquaphotomics.com. The essential properties will be identified within the project. These may include BOD, COD, turbidity, the concentration of elements such as nitrogen, phosphorus and related molecules, heavy metals, various CECs concentrations in wastewater and sludge, other QA/QC indicators, classification/discrimination of components, etc.

The second part of the study will evaluate the potentials and limitations of the technology and develop a possible implementation strategy for introducing such sensors to the complex production systems of wastewater treatment plants WWTPs or elsewhere. The overall aim is to improve resource recovery from wastewater and sludge and therefore contribute to the circular economy concept.

Organizations: Mälardalens univeristet

Contact: Jan Skvaril, Mälardalens univeristet. jan.skvaril@mdu.se; Ali Ahmad Shahnawazi, ali.ahmad.shahnawazi@mdu.se.

More information: Here Pdf, 167.1 kB, öppnas i nytt fönster. (Pdf, 167.1 kB).

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Hyperspectral imaging spectroscopy and aquaphotomics combined with artificial intelligence for monitoring crop growth and quality in an urban vertical farm (15 hp/30 hp)

Background: According to the UN ́s Food and Agriculture Organization, the world community must find new climate-friendly solutions to increase food production by 70%, mainly due to the world population rising to 10 billion in 2050. Diversifying the food chain where alternative and local food production facilities such as urban farms are introduced can address this challenge. Urban farming brings many advantages compared to conventional agriculture production, such as a controlled environment.

There is a great demand for sensors that monitor plant growth and growth conditions and factors and detect anomalies as early as possible. Identifying anomalies in the early stage allows for the appropriate introduction of correction measures, e.g., temperature control, pH control, light intensity adjustments, etc.

Hyperspectral imaging and single-point NIR sensors can provide a real-time, rapid, non-destructive crop nutrient monitoring method to optimize the plant growth cycle. The capability to monitor plants in vertical urban farming can be further enhanced by implementing a novel scientific discipline in called aquaphotomics https://www.aquaphotomics.com. This methodology has great potential to complement standard qualitative and quantitative NIR spectroscopic analysis involving machine learning and artificial intelligence.

Content: The project aims to demonstrate the potential to implement state-or-art spectroscopy sensors and a novel scientific discipline - aquaphotomics to achieve better results in plant growth monitoring in vertical urban farm facilities to achieve optimal results. Specifically, the project aims to establish and evaluate how the low-cost single point and Hyperspectral imaging near-infrared sensors can be used and integrated into an urban vertical farm system to achieve optimal plant growth. It is followed by the evaluation of how can the aquaphotomics approach complement the standard chemometric approach to enable real-time monitoring of plant growth in the facility.
The project's exact tasks will be defined based on the student interests considering requirements for the degree project in different educational programmes.

Organizations: Mälardalens univeristet

Contact: Jan Skvaril, Mälardalens univeristet. jan.skvaril@mdu.se

More information: The project is suitable for both Master's (30 hp) and Bachelor's (15 hp) degree project works in environmental engineering and energy fields and can accommodate up to 4 students.

The proposed degree project is based on activities that are being done in an ongoing research project, Aqua2Farm Länk till annan webbplats, öppnas i nytt fönster. – Boosting sustainable urban farming by near-infrared spectroscopy with aquaphotomics.

Read more about the project here Pdf, 291.4 kB, öppnas i nytt fönster. (Pdf, 291.4 kB).

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Measurements of leafy vegetable properties with advanced handheld spectral sensor (15 hp/30 hp)

Background: According to the UN ́s Food and Agriculture Organization, the world community must find new climate-friendly solutions to increase food production by 70%, mainly due to the world population rising to 10 billion in 2050. Diversifying the food chain where alternative and local food production facilities such as urban farms are introduced can address this challenge. Urban farming brings many advantages compared to conventional agriculture production, such as a controlled environment.

There is a great demand for sensors that monitor plant growth and growth conditions and factors and detect anomalies as early as possible. Identifying anomalies in the early stage allows for the appropriate introduction of correction measures, e.g., temperature control, pH control, light intensity adjustments, etc.

Handheld NIR sensors can provide a real-time, rapid, non-destructive crop nutrient monitoring method to optimize the plant growth cycle. The capability to monitor plants in vertical urban farming can be further enhanced by implementing a novel scientific discipline in called aquaphotomics https://www.aquaphotomics.com. This methodology has great potential to complement standard qualitative and quantitative NIR spectroscopic analysis involving simple linear regression algorithm but potentially also machine learning and artificial intelligence.

Content: The project aims to demonstrate the potential to implement state-or-art spectroscopy sensors and potentially a novel scientific discipline - aquaphotomics to achieve better results in plant growth monitoring in vertical urban farm facilities to achieve optimal results. Specifically, the project aims to establish and evaluate how the low-cost handheld near-infrared sensors can be used and integrated into an urban vertical farm system to achieve optimal plant growth. It is followed by the evaluation of how can the aquaphotomics approach complement the standard chemometric approach to enable real-time monitoring of plant growth in the facility.

The project's exact tasks will be defined based on the student interests considering requirements for the degree project in different educational programmes.

Organizations: Mälardalens univeristet

Contact: Jan Skvaril, Mälardalens univeristet. jan.skvaril@mdu.se

More information: The project is suitable for both Master's (30 hp) and Bachelor's (15 hp) degree project works in environmental engineering and energy fields and can accommodate up to 4 students.

The proposed degree project is based on activities that are being done in an ongoing research project, Aqua2Farm Länk till annan webbplats, öppnas i nytt fönster. – Boosting sustainable urban farming by near-infrared spectroscopy with aquaphotomics.

Read more about the project here Pdf, 217.9 kB, öppnas i nytt fönster. (Pdf, 217.9 kB).

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Recovery of nutrients and reuse of wastewater for sustainable and circular food production (15 hp/30 hp)

Background: Growing population and climate change bring many challenges to the agriculture food production sector, which is characterized by low resource and energy efficiency, high transportation distances, high demands of mineral fertilizers and pesticides, and substantial water wastage. Addressing such a challenge will create an additional environmental burden when society strives to decrease environmental impact and carbon footprint.

Therefore, there is a need to effectively intensify local food production that demands a focus on achieving circular and sustainable food production. Indoor urban vertical farming (IUVF) concepts bring many advantages compared to standard agriculture production. IUVF achieves higher efficiencies in the utilization of water and production yield. IUVF further brings an opportunity to cycle the nutrient streams (N, P, C, K, and micronutrients) by recovering them from waste, wastewater, and water streams by reusing transformed wastewater for irrigation.

Content: The project aims to investigate the possibilities of recovering nutrients and reusing transformed wastewater for food production. The project's first part will include mapping qualities and quantities of the recoverable nutrients and water in a given city or region. Available and novel technologies and concepts of nutrient recovery and wastewater transformation will be investigated. Evaluation of the concepts will be done considering which form the nutrients are presented to the plants to enable optimal nutrient intake by crops.

The second part of the study will evaluate the sustainability and circularity of local food production with resource and nutrient recovery through LCA. It will be used in combination with other methods such as nutrient and energy balances and material circularity indicator (MCI) or equivalent.

The project's exact tasks will be defined based on the student interests considering requirements for the degree project in different educational programmes.

Organizations: Mälardalens univeristet

Contact: Jan Skvaril, Mälardalens univeristet. jan.skvaril@mdu.se

More information: The project is suitable for both Master's (30 hp) and Bachelor's (15 hp) degree project works in environmental engineering and energy fields and can accommodate up to 4 students.

The proposed degree project is based on activities that are being done in an ongoing research project, Trace4Value Länk till annan webbplats, öppnas i nytt fönster. – Traceability for sustainable value chains, nutrient reuse and food production in circularity.

Read more about the project here Pdf, 264.2 kB, öppnas i nytt fönster. (Pdf, 264.2 kB).

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Phytoremediation for PFAS treatment in municipal wastewater-literature review study (30 hp)

Background: The contamination of freshwater resources with emerging contaminants such as per- and polyfluoroalkyl substances (PFASs) is a major global issue challenging the United Nations Sustainable Development Goals. The uncontrolled discharge of PFAS from different sources (like food packaging, oil production, firefighting foams, mining, hospitals, domestic discharge, animal rearing etc.) is faster than the degradation rates of these compounds. It is well known that PFAS is synthetic compound with highly toxic effects at low concentrations. Conventional physiochemical methods for the treatment of PFAS are lacking efficiency and the goal of this thesis is to study the performance of phytoremediation as a treatment method for these emerging compounds in municipal wastewater.

Tasks:

1. Scanning the PFAS compounds in different municipal wastewater treatment plants in Sweden based on a literature review study.
2. Studying the performance of phytoremediation of PFAS compounds in wastewater by selecting plants that can tolerate Swedish climate.

Organizations: Mälardalens univeristet

Contact: Yahya Jani, Mälardalens universitet. yahya.jani@mdu.se, 021-10 70 83

More information: here Pdf, 112.4 kB, öppnas i nytt fönster. (Pdf, 112.4 kB).

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Nutrients extraction from dredged sediments by biological or chemical method, which method is the optimal? (30 hp)

Background: More than 200 million tons of contaminated sediments are dredged within the European borders annually. These sediments are usually contaminated by different organic and inorganic contaminants such nutrients (phosphors and nitrogen) which can leach directly to the environment if physiochemical properties changing during the dredging process. On the other hand, nutrients have been extensively used for different anthropogenic activities like agriculture leading to the reduction of these important materials in their primary resources. In this master thesis the focus will be given to study methods of extracting nutrients in sediments based on a review study for the already published studies in this field to find the optimum methods for extracting nutrients from sediments with cost, environment and technical aspects.

Tasks:

1. Identify two methods (biological and chemical) for the extraction of nutrients from dredged sediments.
2. Optimum study based on, cost, environment and technical factors in between the two selected methods.

Organizations: Mälardalens univeristet

Contact: Yahya Jani, Mälardalens universitet. yahya.jani@mdu.se, 021-10 70 83

More information: here Pdf, 110.6 kB, öppnas i nytt fönster. (Pdf, 110.6 kB).

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Artificial intelligence and aquaphotomics for real-time measurements of hydroponic solution for optimization of urban farm operation (15 hp/30 hp)

Background: Hydroponics is a type of horticulture that grows crops without the presence of soil, by using water-based nutrient solutions in aqueous solvents. Crops may be grown hydroponically in a greenhouse or indoor urban vertical farm (IUVF) in a controlled-environment agriculture process. The nutrients used may come from different sources, such as artificial nutrient solutions, fish excrement, or duck manure. In such a system, the roots of the plants are mechanically supported by an inert medium, so-called “grow cubes,” usually made of Rockwool material.

One of the biggest challenges in hydroponics research is finding effective, preferably on-line, real-time measurements of nutrient concentrations in hydroponic solutions and its dynamic changes. Knowledge of nutrient concentration is crucial to get insight into plant nutrient uptake, measuring fertilization and optimizing the urban farm operation and control, leading to significant energy savings and environmental benefits.

Content: The project aims to develop real-time measurement methods for a hydroponic solution by soft-sensors with the help of artificial intelligence (AI), machine learning algorithms, and data from optical sensors, including NIR and UV-Vis spectrometers. Furthermore, a method called aquaphotomics will be considered in the method development https://www.aquaphotomics.com. The essential properties will be identified within the project and may include the concentration of macro and micronutrients and metals (e.g., NO3-N, NO4-N, total N, PO4, P, K, Mg, S, Ca, Mn, B, Cu Fe, Zn, Mo, Si, Na, Cl, Al etc.). The involved experimental protocol will follow the principles of Design of Experiment (DoE) and mixture design, where various nutrient-rich substances with known concentrations will be mixed with water at different proportions. The NIR/UV-Vis spectral data will then be correlated to the calculated mixed quantities leading to the construction of AI/ML-based predictive models. The second part of the study will evaluate the potentials and limitations of the soft-sensor and real-time measurements for application in indoor urban vertical farm (IUVF) facility in Stockholm.

The project's exact tasks will be defined based on the student interests considering requirements for the degree project in different educational programs.

Organizations: Mälardalens univeristet

Contact: Jan Skvaril, Mälardalens univeristet. jan.skvaril@mdu.se; Reyhaneh Gorji, Mälardalens univeristet. reyhaneh.gorji@mdu.se

More information: The project is suitable for both Master’s (30 hp) and Bachelor’s (15 hp) degree project works in environmental engineering and energy fields and can accommodate up to 4 students.

Read more about the project here Pdf, 255.9 kB, öppnas i nytt fönster. (Pdf, 255.9 kB).

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Environmental impacts of the European Energy Crisis (30 hp)

Background: Today we are facing an energy crisis in Europe. The most affected countries are the ones that most strongly dependent on the Russian gas, but the repercussions are felt in almost all the European countries as the energy prices are soaring and several countries have also implemented policies for energy rationing.

While this energy crisis is a huge problem, it can also give the opportunity for Europe to be more energy efficient, invest in more renewable energies sources and become more energy independent. The implementation of renewable energy systems however take time to plan and build and several countries need to rely on short-term measures.

The natural gas reserves in Europe may last over the winter, but several countries have already acted and put in place a number of short-term measures to fill up the gap in primary energy. The most common measure has been to buy natural gas from the USA. 60% of USA’s liquefied natural gas exports are now coming to Europe.

The goal of this degree project is two-fold, (i) investigate the environmental impacts in terms of CO2 emissions, from the short-term energy measures and (ii) suggest a long-term energy plans to replace natural gas with renewable energy based on the perspective of the different EU countries.

Uppgift: The task will be: (i) Select the EU countries with the highest dependency on natural gas from Russia, (ii) Investigate their energy system prior to the crisis and the short-terms solutions that they are taking to fill the gap in primary energy, (iii) Calculate the impact on the CO2 emissions of the short-term solutions., (iv) Suggest different scenarios for renewable energy sources that could be implemented in the selected countries and investigate the environmental benefits.

Organizations: Mälardalens univeristet

Contact: Allan Hawas, Mälardalens universitet. allan.hawas@mdu.se; Lara Carvalho, Mälardalens universitet. lara.carvalho@mdu.se

More information: Read more about the project here Pdf, 92.4 kB, öppnas i nytt fönster. (Pdf, 92.4 kB).

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Energy and nutrient recovery from horse manure (3 exjobb)

Background: Horse manure handling and disposal is becoming an economical burden for horse-stable owners for two main reasons: (1) high costs to transport the waste from the stables to waste disposal plants and (2) rising cost of wood pellets, which is the material normally used as bedding material. A more local disposal solution of horse manure that can bring back the nutrients to the soil while reducing the costs in fertilizers can be investigated.

Hydrothermal carbonization (HTC) is an energy-efficient thermochemical process that can convert wet waste materials, such as horse manure, into hydrochar (a carbon-rich and porous solid similar to charcoal) and reject water. The hydrochar can have a variety of applications, such as (i) filter material for nutrients and heavy metals removal, (ii) soil amendment, (iii) catalyst in anaerobic digestion and (iv) energy source. While the reject water could be used in irrigation and as fertilizer.

Under this topic, there is the possibility for three degree projects with the overall objective of increasing the knowledge of implementing an HTC system to dispose horse manure in-situ while recovering nutrients/energy.

Tasks:
Thesis 1: Your task will be to (1) make a literature review on HTC of horse manure, (2) perform HTC experiments at different temperatures, (3) analyse the hydrochar and reject water suitability as nutrients or energy carrier based on the chemical composition, (4) simplified system analysis based on different scenarios to find out the potential savings for owners of horse stables.

The student needs to be in Västerås to perform experimental work for a period of 3 to 6 weeks

Thesis 2: Your task will be to (1) make a literature review on the possibility of use horse manure derived hydrochar and reject water as soil amendment and fertilizer, (2) perform simple pot experiments to investigate the potential benefits on (i) plant germination, (ii) plant yield and (iii) carbon capture from adding hydrochar as soil subtract and reject water as fertilizer, (3) estimate the potential financial and energetic savings as well the reduction in greenhouse gas emissions if hydrochar or reject water can partially or fully substitute artificial fertilisers.

The student needs to be in Västerås to perform experimental work for a period of 2 months.

Thesis 3: Your task will be to (i) make a literature review on techno-economic analysis of applying HTC in horse stables as well as different applications for the hydrochar and reject water, (ii) make a scenario-based systems analysis to investigate the technical, economic, and environmental benefits of implementing HTC to convert horse manure into valuable products. It may include modelling work (in Aspen or Matlab) and different applications of hydrochar and reject water should be investigated.

This thesis work can be done at distance.

The students will have the opportunity to collaborate with a horse-stable owner (Lars-Åke Edgardh) that has a farm with 24 horses. Lars-Åke will supply horse manure for the lab experiments and data required to perform the economic and environmental analysis.

Organizations: Mälardalens univeristet

Contact: Lara Carvalho, Mälardalens universitet. lara.carvalho@mdu.se

More information: Read more about the project here Pdf, 110.1 kB, öppnas i nytt fönster. (Pdf, 110.1 kB).

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Understanding the mass balance of heavy metals in wastewater treatment plants (30 hp)

Background: A relatively new concept in municipal wastewater treatment is “wastewater resource recovery facilities”. The objective of wastewater treatment is no longer to “only” protect freshwater resources, but also to achieve reuse of nutrients, organic matter, and water. Sludge, generated during municipal wastewater treatment, is rich in organic matter with typically high levels of nutrients (mainly phosphorus) that should be returned to the food chain. However, its direct application as soil fertilizer poses environmental and health risks in the sense that sewage sludge also contains heavy metals and other contaminants.
To avoid soil and food contaminated with heavy metals, only certified sewage sludge can be used in agricultural lands. The certification process is carried out through REVAQ, that defines a set of threshold values for certain heavy metals in sewage sludge.The trend over the past decades is that heavy metal loads have decreased. However, our recent findings indicate that the heavy metal mass balances over the treatment process are not fully understood. As the recovery of the high nutrient content of sewage sludge is constrained by the heavy metal concentrations, increasing the knowledge of the metals mass balance within the wastewater treatment plants is crucial to improve the recovery and reuse of valuable nutrients.

The goal of this thesis is to perform a mass balance of the heavy metals by looking at different streams in several Swedish wastewater treatment plants. You will try to investigate the reasons for potential deviation in the mass balance (i.e., when the concentrations of the metals do not add up).

Tasks: Perform mass balance studies based on monthly data available for Eskilstuna Strängnäs Energi och Miljö (and potentially additional wastewater utilities in the Mälardalen region), for the most important heavy metals. Depending on the output from the mass balance, further investigations will be decided upon discussion with the supervisor. Further work may include (i) literature search (e.g., identification of likely source of specific metals) or (ii) make additional sampling and chemical analysis at specific points of the plants. The thesis can be written in English or Swedish.

Organizations: Mälardalens univeristet

Contact: Ida Sylwan, Mälardalens universitet. ida.sylwan@mdu.se; Lara Carvalho, Mälardalens universitet. lara.carvalho@mdu.se

More information: Read more about the project here Pdf, 95.8 kB, öppnas i nytt fönster. (Pdf, 95.8 kB).

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