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Ecological risks assessment of organophosphorus pesticides based on response of Scenedesmus quadricanda |
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Abstract Ecological risks assessment of organophosphorus pesticides, glyphosate-isopropylammonium(Glyphosate IPA) and chlorpyrifos, were conducted based on the chlorophyll a fluorescence of S. quadricanda in batch cultures. The dosage response was hypothesized as toxic effect under high concentrations and stimulating effect at low concentrations, besides, utilization of OPPs as sole phosphorus source were tested. The results showed median inhibitory effect concentrations of glyphosate IPA and chlorpyrifos at 96h were 12.98 μmol/L and 2.02 μmol/L respectively. The cell density and the maximum photochemical efficiency (Fv/Fm) were promoted significantly at low concentrations of glyphosate IPA (0.014~1.35 μmol/L), moreover, glyphosate IPA could be used as sole phosphorus source to sustain growth of S. quadricanda at the range of 0.40~0.67 μmol/L notably. However, such effects were not detected in chlorpyrifos treatments. In conclusion, ecological risks of OPPs were dominated by significant stimulating effect in yield, meanwhile, dynamic variation of algae community could be induced by organophosphorus pesticides at the deficiency of inorganic phosphorus.
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Received: 10 August 2012
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