Substance Flow Analysis (SFA) of Persistent Organic Pollutants (POPs) in Road Runoff

Background: Thousands of organic substances circulate in our society and are diffusely emitted through traffic, combustion and leaching from constructions and building materials into the urban environment. Stormwater runoff can transport pollutants from urban surfaces into storm sewers and waterways, which act as important pollutant sinks; approximately 600 specific compounds have been observed in urban runoff and rainwater worldwide. The highest concentrations of pollutants are frequently found in runoff from areas with high traffic intensity; hence this project focuses on road runoff. The contribution of urban surfaces and highway runoff to pollution of urban water systems has become an issue in receiving water remediation plans, especially when changes in water quality and toxic effects are in focus. Recent studies show that organic compounds like phthalates, alkylphenols, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are ubiquitous in urban runoff from cities in Sweden. Many of these organic substances are toxic, persistent, bio-accumulating, carcinogenic, hormone disrupting and have the ability to bio-magnify in aquatic and terrestrial ecosystems.

Outcomes: The result from the SFAs will be used as a basis for applicable preventative actions for pollution of POPs in urban areas, and for re-thinking treatment techniques for efficient removal of organic pollutants. The findings will support the EU and Sweden effort in reaching set environmental goals for water quality. The results are relevant to stakeholders responsible for the protection of stormwater quality, such as landowners, municipalities, transportation and environment departments.

Aim and goals: In the suggested master thesis project, identification, quantification, emissions and flows of POPs from vehicles, fuels and road construction materials will be studied. The aim is to perform substance flow analysis (SFAs) of selected persistent organic pollutants (POPs) in road runoff, and the data will be used to quantify the most important sources of road-runoff pollutants. The specific goals are to:

–          identify the most important sources in the road environment for some selected POPs by search in the literature, data bases (KEMI, SCB) and interviews with users.

–          from the literature and searched data, quantify the amounts of the POPs in the road structure and its surrounding construction materials, vehicle parts, car-care products, fuels, oils and exhaust emissions.

–          determine or estimate the emission coefficients for each sources, based on data from the literature and studies of concentrations measured in stormwater.

–          investigate the probability of colloidal transport of the POPs in road runoff.

–          perform a SFA for the selected POPs with the Gårda catchment area in Gothenburg as case study area.

–          perform sampling on water and sediment at the Gårda catchment area to confirm the emissions determined in the SFA.

Supervisors: Docent Ann-Margret Strömvall, Docent Yuliya Kalmykova, Post-doc Karin Björklund and PhD student Anna Markiewicz. All Water Environment Technology, Chalmers University of Technology. The project is carried out in the frames of the FRISTcompetence center (Forum for Risk investigation and Sustainable Technology) at Chalmers: www.frist.chalmers.se

This research project is part of an international co-operation on organic pollutants in stormwater between Chalmers University of Technology, Technical University of Denmark (DTU) and University of British Columbia (UBC). The project has financial support from FORMAS.

Contact: ann-margret.stromvall@chalmers.se

Number of students: 2 – 4 working in pairs, with each pair working with 2– 3 groups of POPS

Time plan: January 2015 – June 2015

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