Speciering av zink i dagvatten från motorvägstunnlar
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesisAlternative title
Zinc Speciation in Stormwater from Motorway Tunnels (English)
Environmental risks are being investigated more and more in Sweden in relation to large infrastructural projects such as the Stockholm Bypass, a 21km long motorway tunnel where 18km is underground. This project specifically evaluates the metal zinc’s effect on the nearby environment by determining the speciation that the metal is found in. The process included analyzing the stormwater from another tunnel in Stockholm called Södra Länken where samples at five independent locations were taken. A rain sample was taken as a background sample to compare with the natural conditions. The practical lab work was complemented with theoretical modeling by the software Medusa and MinTeq. The total accessible metal concentration was evaluated by decreasing the pH value successively. Results shows that the concentration accessible zinc is below the limit value set for Sweden at neutral to high pH values and the concentration increases with decreasing pH value. If humic substances are present, MinTeq modelling shows that low concentrations of free zinc ion are found accordingly. The conclusion of this study is that the planned construction of the Stockholm Bypass has a well-adapted stormwater treatment strategy that will function well. Future studies should complete this project with a study of the natural zinc concentrations fluctuations, which could contribute to a more detailed analysis of the stick samples taken.
Place, publisher, year, edition, pages
2015. , 60 p.
zinc, zinc speciation, stormwater, motorway tunnel, environmental impact
IdentifiersURN: urn:nbn:se:kth:diva-172145OAI: oai:DiVA.org:kth-172145DiVA: diva2:846045