uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Influence of particle size distribution, organic carbon, pH and chlorides on washing of mercury contaminated soil
Waste Science and Technology, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology.
Show others and affiliations
2014 (English)In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 109, p. 99-105Article in journal (Refereed) Published
Abstract [en]

Feasibility of soil washing to remediate Hg contaminated soil was studied. Dry sieving was performed to evaluate Hg distribution in soil particle size fractions. The influence of dissolved organic matter and chlo- rides on Hg dissolution was assessed by batch leaching tests. Mercury mobilization in the pH range of 3– 11 was studied by pH-static titration. Results showed infeasibility of physical separation via dry sieving, as the least contaminated fraction exceeded the Swedish generic guideline value for Hg in soils. Soluble Hg did not correlate with dissolved organic carbon in the water leachate. The highest Hg dissolution was achieved at pH 5 and 11, reaching up to 0.3% of the total Hg. The pH adjustment was therefore not suf- ficient for the Hg removal to acceptable levels. Chlorides did not facilitate Hg mobilization under acidic pH either. Mercury was firmly bound in the studied soil thus soil washing might be insufficient method to treat the studied soil. 

Place, publisher, year, edition, pages
2014. Vol. 109, p. 99-105
Keyword [en]
Organic matter, Mobilization pH-dependent, dissolution, Soil remediation
National Category
Environmental Sciences
Identifiers
URN: urn:nbn:se:uu:diva-224367DOI: 10.1016/j.chemosphere.2014.02.058OAI: oai:DiVA.org:uu-224367DiVA, id: diva2:716456
Available from: 2014-05-09 Created: 2014-05-09 Last updated: 2018-03-15Bibliographically approved
In thesis
1. Remediation of mercury contaminated soil and biological mercury methylation in the landscape
Open this publication in new window or tab >>Remediation of mercury contaminated soil and biological mercury methylation in the landscape
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Accumulation of mercury (Hg) in soil originating from both natural and anthropogenic sources poses a major hazard to environmental and human health. Inorganic Hg(II) in soil can be transformed to highly toxic methylmercury (MeHg) mainly via methylating microorganisms. Although MeHg constitutes less than 2% of total Hg in soil, it enters aquatic systems through runoff and can be subsequently bioaccumulated along the food chain, thereby causing severe harm to humans.

Current major remediation techniques to control soil Hg contamination were reviewed. Organic matter, clay/minerals and complexation ligands within soil are principal factors influencing Hg mobility that is crucial for evaluating and optimising remedial techniques. The potential of soil washing to treat soil Hg contamination was evaluated. The studied soil was fractionated from fine to coarse particles to assess the effectiveness of physical separation. Batch leaching and pH-static titration tests were performed using (1) water, (2) EDTA, (3) NaOH, (4) HCl, (5) acidic leachates from biodegradable wastes, and (6) alkaline leachates from fly/bottom ashes, to estimate the efficiency of chemical extraction. Less than 1.5% of the total Hg could be mobilised after combined treatments, implying very tight binding of Hg to soil particles, thereby hampering soil washing as a strategy for the studied soil.

Hg(II) methylation in boreal soils and lake sediments can have major consequences for MeHg inputs to downstream aquatic systems. It is therefore important to understand the biogeochemical mechanisms involved in MeHg formation in these landscapes. The microbes involved in Hg(II) methylation in sediments and boreal forests and wetlands were investigated by high-throughput 16S rRNA and hgcA sequencing with molecular barcoding. In all three environments, hgcA sequences were distributed among Proteobacteria, Firmicutes and Euryarchaeota, and Deltaproteobacteria, particularly Geobacteraceae, appeared to play a predominant role. Ruminococcaceae were also abundant Hg(II) methylators in soils from one forest and all the wetlands. The boreal forest survey provided some first insights about the possible link between 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. Furthermore, the interactions between Hg(II) methylating groups revealed that the more anaerobic and productive conditions seemed to favour 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. Our findings provide a better understanding of Hg(II) methylating communities in the landscape.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 57
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1643
Keyword
Mercury contamination, Soil remediation, Methylmercury, Mercury methylation, hgcA, Community composition, Bacteria, Landscape
National Category
Environmental Sciences
Research subject
Biology with specialization in Microbiology
Identifiers
urn:nbn:se:uu:diva-345626 (URN)978-91-513-0267-6 (ISBN)
Public defence
2018-04-27, Hambergssalen, Villavägen 16, Uppsala, 09:00 (English)
Opponent
Supervisors
Available from: 2018-04-06 Created: 2018-03-10 Last updated: 2018-04-24

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Jingying, Xu

Search in DiVA

By author/editor
Jingying, Xu
In the same journal
Chemosphere
Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 560 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf