Sulfide mineral biodegradation and phytotoxicity of the resulting products
Authors | |
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Year of publication | 2002 |
Type | Article in Proceedings |
Conference | 12th Int. Biodeterioration and Biodegradation Symp. |
MU Faculty or unit | |
Citation | |
Field | Ecology |
Keywords | sulfide biooxidation; Thiobacillus; phytotoxicity; pyrite; arsenopyrite |
Description | Sulfuric acid and toxic metals are environmental contaminants released from sulfide mines and wastes as a result of the sulfide mineral (bio)oxidation processes. Electrochemical and kinetic studies on mechanism of arsenopyrite oxidation by Acidithiobacillus ferrooxidans specified the forms of arsenic in the oxidation products. Studies on mechanism of pyrite and sulfur oxidations demonstrated an indirect role of bacteria in oxidation of these solid substrates. The main products of the above processes are sulfuric acid, arsenic(III), arsenic(V) as a secondary product, iron(III) and sulfates. The above substances were the subjects of phytotoxicity tests (root elongation and seed germination of Lactuca sativa) under specific conditions of acidic environment of sulfide wastes. Interference effects on metal phytotoxicity determination were demonstrated on iron. Under conditions of controlled iron solubility, constant pH and ionic strength, defined phytotoxic parameters were determined to evaluate solely the effect of iron. EC50 values differed from those described in the literature. |
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