Abstract
Inhibitory effects of selenite and selenate towards hydrogenotrophic and acetoclastic methanogenesis were evaluated in anaerobic toxicity assays. The 50% inhibitory concentration (IC50) of both selenium oxyanions was below 6.1 X 10(-5) M in hydrogenotrophic assays, whereas acetoclastic methanogens were less inhibited: IC50 = 8.3 x 10(-5) M and 5.5 x 10(-4) M for selenite and selenate, respectively. Selenite completely inhibits methanogenesis from both substrates tested at concentrations >= 10(-3) M selenite, while only marginal methanogenic activities occur at equimolar concentrations of selenate. Selenite becomes irreversibly inhibitory upon a single exposure, whereas selenate inhibits methanogens upon repeated exposure. Consequently, methane recovery can be seriously hampered or even impossible during anaerobic treatment of highly selenium contaminated waste streams.
Original language | English |
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Pages (from-to) | 383-388 |
Journal | Chemosphere |
Volume | 73 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2008 |
Keywords
- anaerobic granular sludge
- agricultural drainage sediment
- escherichia-coli
- thauera-selenatis
- waste-water
- elemental selenium
- sulfate reduction
- bed reactors
- bioremediation
- removal