Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation
Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation
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DOI：
10.1016/j.chemosphere.2017.05.169
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发表时间：
2017-10-01
期刊：
影响因子：
8.8
通讯作者：
Mayer, Philipp
中科院分区：
文献类型：
--
作者：
Birch, Heidi;Hammershoj, Rikke;Mayer, Philipp
生物降解是许多有机污染物的主要去除过程，生物降解试验是在监管风险评估中评估其环境归宿的工具。在模拟试验中，接种物没有标准化，微生物数量和质量不同，从而可能影响观察到的生物降解动力学。在这项研究中，我们调查的影响接种源的生物降解动力学的碳氢化合物的五个接种物从地表沃茨不同的城市化，从而预期预暴露于石油烃。一种新的生物降解方法，测试混合物的疏水化学品在痕量浓度的证明：水溶液含有9烃产生被动剂量和稀释的地表水导致测试系统含有原生微生物暴露于测试物质在ng-mug/L的水平。将自动顶空固相微萃取与GC-MS联用直接应用于这些试验系统，以测定相对于非生物对照的底物消耗。滞后期一般小于8天。一阶速率常数在一个数量级内的每种碳氢化合物在四个五沃茨，但较低的水从农村湖泊。9种碳氢化合物之间的降解顺序在五种沃茨中显示出相似的模式，表明在生物降解试验之间使用选定的碳氢化合物作为基准的潜力。降解半衰期比BioHCwin预测的9种碳氢化合物中的8种短或在一个数量级内。这些结果表明，位置的选择是重要的生物降解动力学，并可以提供一个相关的输入水生接触和命运模型。(C)2017爱思唯尔有限公司版权所有
Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng-mu g/L levels. Automated Headspace Solid Phase Microextraction coupled to GC-MS was applied directly to these test systems to determine substrate depletion relative to abiotic controls. Lag phases were generally less than 8 days. First order rate constants were within one order of magnitude for each hydrocarbon in four of the five waters but lower in water from a rural lake. The sequence of degradation between the 9 hydrocarbons showed similar patterns in the five waters indicating the potential for using selected hydrocarbons for benchmarking between biodegradation tests. Degradation half-times were shorter than or within one order of magnitude of BioHCwin predictions for 8 of 9 hydrocarbons. These results showed that location choice is important for biodegradation kinetics and can provide a relevant input to aquatic exposure and fate models. (C) 2017 Elsevier Ltd. All rights reserved.