Modelling fate and transport of perfluorinated compounds in Lake Ekoln
Lake Ekoln is polluted with perfluorinated (PFOS) compounds. Pollutant reach the lake with wastewater discharges from Uppsala, through the esker that got polluted due to fire extinguishing exercises at the Ärna airport, and through the air. PFOS is very stable in the environment and can be transported long distances. Through Lake Ekoln. pollutants can reach Lake Mälaren and the water intake of the Görnväln drinking water treatment serving 600 000 consumers in Stockholm and neighbouring municipalities. In a previous project, a hydrodynamic model of Lake Ekoln was set-up in MIKE 3 by DHI software. In this MSc thesis project, this model will be used to simulate the spread of PFOS with the lake.
The aim is to analyse pathways, transport times, and trends for PFOS in Lake Ekoln. The existing hydrodynamic model of Lake Ekoln will be used to simulate the spread of PFOS and test scenarios that can lead to critical situations.
This project will be performed in contact with drinking water producer Norrvatten.
Modelling impacts of climate and land use changes on Lake Vomb
Lake Vomb is a small lake in Scania, the southernmost part of Sweden, providing 330 000 consumers with drinking water. The microbial water quality in the lake is impacted by the activities in its catchment: the on-site sewers, fertilization using manure, grazing animals. In previous projects, a hydrological ArcSWAT model was set-up to simulate water and pollution transport in the lake’s catchment, and a hydrodynamic model MIKE 3 by DHI was set-up to describe the pollutant fate and transport within the lake. In this MSc thesis project, these models will be used to assess the impact of climate and land use changes on the microbial water quality in Lake Vomb. Aim:
The aim is to use the existing hydrological and hydrodynamic models for Lake Vomb to simulate the spread of faecal pollutants under future conditions of climate and land use change. Other:
This project will be performed in contact with Nynke Hofstra at the Wageningen University in the Netherlands.Contact:
Ekaterina Sokolova, Chalmers, email@example.com
Prediction of water quality in the Göta River with machine learning
The opportunity for recreational bathing in the Göta river in Gothenburg is hindered by the varying microbial water quality in the river, which at times does not fulfil the bathing water quality standards. The water quality in the river is continuously monitored at several stations along the river, since the river is used as a drinking water source. The data collected at the monitoring stations along the river can be utilised to develop an early warning system that would predict the compliance with bathing water quality standards and issue early warnings for beach closures in case on non-compliance.
The aim of this MSc thesis project is to develop a data-driven model using machine learning methods based on data from the monitoring stations along the Göta River, in order to be able to describe and predict microbial water quality in the river.
This project will be performed in contact with Ibrahim A. Hameed at NTNU in Norway.
Risk assessment for de facto (unintended) water reuse in South Africa
The drought conditions and increasing frequency of localised droughts in South Africa, coupled with poor operation of wastewater treatment plants, have lead to a drastic deterioration of water quality in surface waters due to a high wastewater content.
A large number of water supply authorities and water service providers are dependent on these polluted water sources for drinking water supply to the communities that they serve. The drinking treatment plants that were originally provided for drinking water production were not designed to treat poor quality water, and consisted of conventional water treatment processes. As the raw water quality deteriorated, provision was made to add new or modify existing treatment processes, but this was only done on a project by project basis, and only at the larger water treatment plants, resulting in a high risk for pollutants (in particular micro-pollutants) to pass through the treatment plants and have a health impact on the communities.
A project is currently carried out to quantify the national extent of de facto water reuse in the country. One of the aims of the project is to perform a risk assessment on the health impacts of contaminants of emerging concern on the communities served from these polluted waters, as these contaminants (pharmaceuticals, industrial chemicals, pesticides, etc) will not be removed by convential water treatment plants.
The outcomes of the project will be an understanding of the extent of unplanned reuse in South Africa, and the estimated health impact on the communities served by this de facto water reuse. There will also be an estimation of the potential cost implication of diseases, and treatment of the diseases, associated with de facto reuse. The perception of the South African public towards using water in their homes that forms part of unplanned reuse will furthermore also be an outcome of the project. All of the above outcomes will allow planning and further research into water reuse as an alternative water source in the country, which is of critical importance at the moment due to the increasing occurrence of droughts situation and incidents of water scarcity.
Approximately February to May 2020.
It is the intention that the risk assessment be undertaken by two Masters students from the Chalmers University of Technology.
Chris Swartz, professional water utilisation engineer based in Cape Town, South Africa. Chris has been supervisor for 6 Masters students from Chalmers University of Technology previously. firstname.lastname@example.org
Quantitative microbial risk assessment (QMRA) and climate change
Waterborne gastrointestinal diseases are a major contributor to the global disease burden and mortality. Recent research suggests that the entire drinking water system may suffer due to climate change; and that extreme weather events will increase the incidence of waterborne diseases. Current scientific understanding regarding the impact of climate change on overall public health risk remains ambiguous. To assess drinking water safety, the World Health Organisation recommends a risk-based approach encompassing all steps of the drinking water supply system from the catchment to the consumer. In this light, Quantitative Microbial Risk Assessment (QMRA) is widely used to analyse and inform the management of the drinking water supply system. Generic QMRA tools have been developed to perform QMRA for specific drinking water treatment plants with different treatment trains and varying pathogen levels in the source water. There are also examples of QMRA being applied to quantify relative infection risks for selected waterborne pathogens under different climate change scenarios. Currently, there are several QMRA tools available with different capabilities. In this MSc thesis, these tools will be compared with special focus on their suitability to assess the effects of climate change on microbial risks
The aim is to compare the available QMRA tools and evaluate their suitability to account for climate change effects on the microbial health risks for drinking water consumers.
This project will be performed in contact with Julia Derx at the Vienna University of Technology, Austria.
Uppehållstid för vatten i Larslundsåsen
NOVF har sedan 1960 infiltrerat vatten i åsen vid Larslund. Erfarenhet från driftansvarig sägs att I början på 2000 talet gjordes ett infiltrationsförsök i damm 1. Då användes ett konstgjort salt. Saltet indikerades efter ca 30 dagar. Det finns ingen dokumentation på detta och verksamheten vet inte vilken brunn eller brunnsområde som saltet indikerades.
Under 2016 började verksamheten göra en MBA analys. I och med den behövde verksamheten ta reda på mer exakt om uppehållstiden. Alternativ har utredds hur mätningen ska gå till. Att blanda vanligt koksalt och infiltrera den mättade saltlösningen blev den metod som valdes.
Metoden visade sig inte vara tillförlitlig då saltet aldrig nådde uttagsbrunnarna. Inget salt kunde detekteras under 4 månader. Den troligaste orsaken till att saltet aldrig kom fram är att det sjunkit på djupare nivå ä våra uttagsbrunnar eller ”åkt iväg” på lerskikt i åsen.
Syftet med infiltrationsförsöket är att mäta uppehållstiden för vattnet från det att det släpps i dammarna till dess att vattnet tas upp i brunnsområdena.
Examensarbetaren behöver fundera ut hur ett infiltrationsförsök kan genomföras samt vilka underlag som behövs för att kunna ta fram ett program för infiltration.
Examensarbetaren leder projektet, skriver projektplan, utformar tidplan, uppskattar kostnader, utformar journal och dokumenterar resultat och speciella händelser i projektet. Gör en uppföljning varje vecka för att gå igenom resultat. För en dialog med Laboratoriet i Nyköping angående vilka prover som ska analyseras.
Gör en uppföljning för slutrapport.
Under projektet finns tillgång till verksamhetschef och driftansvarig för NOVF.
Projektet genomförs i samarbete med NOVF, Nyköping-Oxelösunds Vattenverksförbund