Aerobic Biotransformation of N-Nitrosodimethylamine and N-Nitrodimethylamine by Benzene-, Butane-, Methane-, Propane-, and Toluene-Fed Cultures |
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Authors: | Jennifer L Weidhaas Michael J Zigmond R Ryan Dupont |
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Institution: | 1. Department of Civil and Environmental Engineering , West Virginia University , Morgantown , West Virginia , USA;2. National Aeronautics and Space Administration , White Sands Test Facility , Las Cruces , New Mexico , USA;3. Utah Water Research Laboratory , Utah State University , Logan , Utah , USA |
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Abstract: | N-Nitrosodimethylamine (NDMA) is an emerging contaminant of concern. N-nitrodimethylamine (DMNA) is a structural analog to NDMA. NDMA and DMNA have been found in drinking water, groundwater, and other media and are of concern due their toxicity. The authors evaluated biotransformation of NDMA and DMNA by cultures enriched from contaminated groundwater growing on benzene, butane, methane, propane, or toluene. Maximum specific growth rates of enriched cultures on butane (μmax = 1.1 h?1) and propane (μmax = 0.65 h?1) were 1 to 2 orders of magnitude higher than those presented in the literature. Growth rates of mixed cultures grown on benzene (μmax = 1.3 h?1), methane (μmax = 0.09 h?1), and toluene (μmax = 0.99 h?1) in these studies were similar to those presented in the literature. NDMA biotransformation rates for methane oxidizers (υmax = 1.4 ng min?1 mg?1) and toluene oxidizers (υmax = 2.3 ng min?1 mg?1) were comparable to those presented in the literature, whereas the biotransformation rate for propane oxidizers (υmax = 0.37 ng min?1 mg?1) was lower. NDMA biotransformation rates for benzene oxidizers (υmax = 1.02 ng min?1 mg?1) and butane oxidizers (υmax = 1.2 ng min?1 mg?1) were comparable to those reported for other primary substrates. These studies showed that DMNA biotransformation rates for benzene (υmax = 0.79 ng min?1 mg?1), butane (υmax = 1.0 ng min?1 mg?1), methane (υmax = 2.1 ng min?1 mg?1), propane (υmax = 1.46 ng min?1 mg?1), and toluene (υmax = 0.52 ng min?1 mg?1) oxidizers were all comparable. These studies highlight potential bioremediation methods for NDMA and DMNA in contaminated groundwater. |
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Keywords: | biodegradation kinetics NDMA N-nitrodimethylamine N-nitrosodimethylamine |
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