Xu, Jingying, Ph.D. dissertation, Uppsala University, Sweden. 58 pp, 2018

In the first part of this study, an evaluation of the potential of soil washing for Hg remediation showed that <1.5% of total Hg was mobilized after combined treatments, suggesting such tight binding of Hg to soil particles as to render soil washing ineffective. In the second part of the study, the boreal forest survey provided some first insights about the possible link between methylmercury (MeHg) formation and non-Hg(II) methylating bacterial communities that likely support the growth and activity of Hg(II) methylating members. Results from wetlands pointed out nutrient status as an important factor shaping Hg(II) methylating communities across the four wetlands, and highlighted a significant role of water content and iron in controlling the distribution of Hg(II) methylators within individual wetlands. Interactions between the Hg(II) methylating groups revealed that the more anaerobic and productive conditions seemed to favor the activity of Methanoregulaceae and hamper the growth of Ruminococcaceae. Results from lake sediments supported that Geobacteraceae have an important role in Hg(II) methylation under ferruginous geochemical conditions. https://uu.diva-portal.org/smash/get/diva2:1189465/FULLTEXT01.pdf