Storjuktan – Rekonstruktion av ett sekels kvicksilverbelastning.: En undersökning av kvicksilverkoncentrationer i daterat bottensediment.
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesisAlternative title
Storjuktan – A reconstruction of the mercury load of a century. : A study of mercury concentration in dated sediments. (English)
The aim of this study was to examine the current and historic mercury(Hg) load of the lake Storjuktan due to its recent exposure to a local potential source of Hg in form of the Sulphide mine Blaikengruvan(2006) and an earlier potential sources of Hg-load, the damming of the lake(1960s). Sediments were extracted using a HTH-sampler, freeze-dried, and analyzed for tot-Hg, LOI and activity of 210Pb and compared to samples extracted prior to the opening of the mine(2006). Constant initial concentration (CIC)-dating model was used for dating the samples. Low levels of Hg (100ng/g) were found throughout the lakes sediment. The highest levels of Hg(220ng/g) was detected at a depth of 4-5cm dating back to the mid 1970:s, suggesting that increased levels of atmospheric Hg rather than damming of the lake has caused the increase of Hg. No strong evidence for a release of Hg from the local mine was found. However an unexpected layer of anthropogenic sediment with low Hg-levels was found in close proximity to the metal enrichment plant, further supporting that the mine constituted a weak source of Hg. However, the anthropogenic sediment itself covered a large area (ca 22 ha) and its chemical composition calls for further investigation of its extent, properties and ecological impact in Lake Storjuktan.
Keywords: Mercury; Sediment; contamination; Damming; Sweden
Place, publisher, year, edition, pages
2015. , 13 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:umu:diva-104224OAI: oai:DiVA.org:umu-104224DiVA: diva2:818477
Subject / course
Examensarbete i miljö och hälsoskydd
Bachelor of Science in Environmental Health
2015-06-04, NC 250, Umeå, 16:00 (Swedish)