Biotransformation at 10° C of Di‐n‐Butyl Phthalate in Subsurface Microcosms

Abstract

AbstractDi‐n‐butyl phthalate (DBP) was found to be transformed by microorganisms under aerobic and anaerobic conditions at 10° C in microcosms simulating the Canadian Forces Base (CFB) Borden subsurface environment. Biotransformation of DBP was observed under aerobic, nitrate‐reducing, Fe(III)‐reducing, and sulfate‐reducing conditions. The biotransformation of DBP in the microcosms was significantly decreased as the redox potential was lowered, especially under sulfate‐reducing conditions. However, other factors such as nutrient depletion and buildup of toxic intermediates could have affected the biotransformation rates. The highest DBP biotransformation rate (0.57 μg DBP.g sediment−1.day−1) was observed under aerobic conditions whereas the lowest rate (0.05 μg DBP.g sediment−1.day−1) was under sulfate‐reducing conditions. Biotransformation of DBP at 10° C was significantly enhanced by the addition of 10 mM NaNO3 suggesting that both the addition of nitrate and high redox conditions favor its biotransformation in subsurface environments.