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Sulphate reducing bacteria to precipitate mercury after electrokinetic soil remediation

Håkansson, Torbjörn LU ; Suer, P.; Mattiasson, Bo LU and Allard, B. (2008) In International Journal of Environmental Science and Technology 5(2). p.267-274
Abstract
Combined treatment with electroremediation and sulphate reducing bacteria (SRB) was tested in laboratory and pilot scale. The contaminated soil came from a chlor-alkali factory and contained about 100 mg/kg Hg. Iodide/iodine complexing agent was used to mobilize mercury. Mercury iodide complexes were moved to the anode solution using an electric field. The anode solution was then mixed with hydrogen sulphide (H2S) containing water, causing precipitation of mercury sulphide. The H2S was produced at site by a SRB reactor. Precipitation problems arising from the nature of the anode solution were expected, since this solution is highly acidic, very oxidised and may contain iodide/iodine that strongly complexes mercury and can hinder mercury... (More)
Combined treatment with electroremediation and sulphate reducing bacteria (SRB) was tested in laboratory and pilot scale. The contaminated soil came from a chlor-alkali factory and contained about 100 mg/kg Hg. Iodide/iodine complexing agent was used to mobilize mercury. Mercury iodide complexes were moved to the anode solution using an electric field. The anode solution was then mixed with hydrogen sulphide (H2S) containing water, causing precipitation of mercury sulphide. The H2S was produced at site by a SRB reactor. Precipitation problems arising from the nature of the anode solution were expected, since this solution is highly acidic, very oxidised and may contain iodide/iodine that strongly complexes mercury and can hinder mercury sulphide precipitation. Mercury concentrations in the anode solution were up to 65.7 mg/L (field) and 15.4 mg/L (lab. scale). Reduction of mercury in the water was >93% at all times. Iodide did not hinder the process: Nonetheless, in the lab system, iodide concentration was high in the anode solution but mercury reduction was > 99.9%. The redox potential was sufficiently low for HgS precipitation during the experiments, except for a short period, when the mercury removal decreased to 94%. Sulphate reducing bacteria are shown as a viable tool for the treatment of mercury contaminated, acidic, oxidative, iodide containing water, such as that produced by electrokinetic remediation. A second SRB step or other water treatment is required to reduce the mercury concentration to environmentally acceptable levels. Redox. potential is the most sensitive factor in the system. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
soil, wastewater treatment, on site, hydrogen sulphide, in situ, contamination, iodide
in
International Journal of Environmental Science and Technology
volume
5
issue
2
pages
267 - 274
publisher
Center for Environmental and Energy Research and Studies
external identifiers
  • wos:000254582100015
  • scopus:41149171247
ISSN
1735-2630
language
English
LU publication?
yes
id
9aa08801-af4c-4106-92aa-ef8928c18330 (old id 1207489)
alternative location
http://www.ceers.org/ijest/issues/abstract_result.asp?ID=502015
date added to LUP
2008-08-27 09:42:58
date last changed
2017-06-25 03:40:34
@article{9aa08801-af4c-4106-92aa-ef8928c18330,
  abstract     = {Combined treatment with electroremediation and sulphate reducing bacteria (SRB) was tested in laboratory and pilot scale. The contaminated soil came from a chlor-alkali factory and contained about 100 mg/kg Hg. Iodide/iodine complexing agent was used to mobilize mercury. Mercury iodide complexes were moved to the anode solution using an electric field. The anode solution was then mixed with hydrogen sulphide (H2S) containing water, causing precipitation of mercury sulphide. The H2S was produced at site by a SRB reactor. Precipitation problems arising from the nature of the anode solution were expected, since this solution is highly acidic, very oxidised and may contain iodide/iodine that strongly complexes mercury and can hinder mercury sulphide precipitation. Mercury concentrations in the anode solution were up to 65.7 mg/L (field) and 15.4 mg/L (lab. scale). Reduction of mercury in the water was >93% at all times. Iodide did not hinder the process: Nonetheless, in the lab system, iodide concentration was high in the anode solution but mercury reduction was > 99.9%. The redox potential was sufficiently low for HgS precipitation during the experiments, except for a short period, when the mercury removal decreased to 94%. Sulphate reducing bacteria are shown as a viable tool for the treatment of mercury contaminated, acidic, oxidative, iodide containing water, such as that produced by electrokinetic remediation. A second SRB step or other water treatment is required to reduce the mercury concentration to environmentally acceptable levels. Redox. potential is the most sensitive factor in the system.},
  author       = {Håkansson, Torbjörn and Suer, P. and Mattiasson, Bo and Allard, B.},
  issn         = {1735-2630},
  keyword      = {soil,wastewater treatment,on site,hydrogen sulphide,in situ,contamination,iodide},
  language     = {eng},
  number       = {2},
  pages        = {267--274},
  publisher    = {Center for Environmental and Energy Research and Studies},
  series       = {International Journal of Environmental Science and Technology},
  title        = {Sulphate reducing bacteria to precipitate mercury after electrokinetic soil remediation},
  volume       = {5},
  year         = {2008},
}