Jarosite-related chemical processes and water ecotoxicity in simplified anaerobic microcosm wetlands

Zhu, L. and Lin, C. and Wu, Y. and Lu, W. and Liu, Y. and Ma, Y. and Chen, A. (2008) Jarosite-related chemical processes and water ecotoxicity in simplified anaerobic microcosm wetlands. Environmental Geology: International Journal of Geosciences, 53 (7). pp. 1491-1502. ISSN 0943-0105

Abstract

Simulation experiments were conducted to examine whether jarosite is decomposed and toxic products are produced under anaerobic microcosm wetland conditions. The results show that jarosite was stable under water inundation in the microcosm wetland for a period of at least 56 days when no organic substance was added. However, jarosite became increasingly unstable with increasing amount of added organic matter. This resulted in entry of ferrous Fe into the soil solutions. Concentration of other heavy metals in the leachates was extremely low except for Mn. This is attributed to the maintenance of a high pH in the microcosm wetlands, which might cause re-precipitation of originally jarosite-borne heavy metals, if any. No acute toxicity was observed for leachate from the control (non organic matter-added treatment). However, leachates from various organic matter-added treatments show varying degrees of toxicity to the test organism and soluble Fe was likely to be the dominant metal of potential toxicity. Atmospheric exposure of leachate led to oxidation of ferrous Fe and precipitation of iron hydroxide, which caused a drop in leachate pH. This, in turn, inhibited further oxidation of ferrous Fe.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to published version due to publisher copyright policy.
Depositing User: epEditor USQ
Faculty / Department / School: Current - USQ Other
Date Deposited: 25 May 2011 11:32
Last Modified: 20 Oct 2014 05:38
Uncontrolled Keywords: acid mine drainage; aqueous geochemistry; waste management; potassium compounds; decomposition; ecotoxicology; heavy metal; hydrogeochemistry; jarosite; wetlands; leachate; oxidation; hydrogen-ion concentration; soil solutions; organic compounds; iron; toxicity testing
Fields of Research (FOR2008): 05 Environmental Sciences > 0503 Soil Sciences > 050304 Soil Chemistry (excl. Carbon Sequestration Science)
09 Engineering > 0914 Resources Engineering and Extractive Metallurgy > 091405 Mining Engineering
05 Environmental Sciences > 0502 Environmental Science and Management > 050206 Environmental Monitoring
Socio-Economic Objective (SEO2008): D Environment > 96 Environment > 9614 Soils > 961404 Mining Soils
Identification Number or DOI: doi: 10.1007/s00254-007-0758-y
URI: http://eprints.usq.edu.au/id/eprint/18879

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