Influence of Eh/pH - Barriers on releasing /accumulation of manganese and iron at sediment-water interface

Shrestha Reena Amatya, Sillanpää Mika

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The remedy of contaminated soils/sediments with heavy metals and organic compounds is one of major and permanent environmental challenges today. In the most mining areas we found significant concentrations of metals such as lead, copper, chromium, zinc, cadmium, iron, manganese, cobalt, nickel, mercury, arsenic and also halogenated organic compounds and radionuclides. Of those, manganese and iron are always present in huge amount although they are essential metals for all living beings including humans. But, they are very excellent scavengers for other toxic metal and pathogenic microorganisms in the sediment. Therefore, the mobilisation and accumulation of Mn and Fe at the sediment-water interface was studied varying different positions and conditions of the electrode arrangement. The tests were carried out with a natural heavy metal containing in the dredged sediment from the river Weisse Elster (Germany). The electrokinetic experiments have been performed in columns filled with sediment using electrodes made of conductive polymers (polyethylene with carbon black) at a maximum current density of 0.5mA/cm2. The experimental results suggest that the electrokinetic mobilisation and accumulation of Mn and Fe highly depend on chemical factors e.g., pH and redox potential. The sorption of Mn and Fe was very high in the pH range > 4.5. As expected, a high mobilisation of Mn and Fe was seen in the case of the experiment with the anode at the sediment because the pH value was lower than mentioned above. On the opposite, the best conditions for the Mn and Fe-immobilisation are high pH-values (cathode at the sediment). The electrochemically initiated pH- and Eh-barrier is a practicable method to accumulate Mn and Fe and to support the in-situ-cleaning of the sediments.

Original languageEnglish
Pages (from-to)7-13
Number of pages7
JournalResearch Journal of Chemistry and Environment
Volume12
Issue number2
Publication statusPublished - Jun 2008
Externally publishedYes

Keywords

  • Dredged sediment
  • Eh barrier
  • Electrokinetics
  • Heavy metals
  • PH barrier
  • Transportation

ASJC Scopus subject areas

  • Biochemistry
  • General Chemistry
  • General Chemical Engineering
  • Renewable Energy, Sustainability and the Environment
  • General Environmental Science
  • General Agricultural and Biological Sciences
  • General Earth and Planetary Sciences

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