Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, United States.
The Ohio State University, Columbus, OH 43210, United States.
J Environ Manage. 2018 Jan 15;206:60-64. doi: 10.1016/j.jenvman.2017.10.031. Epub 2017 Oct 20.
1,4-Dioxane (dioxane) is a groundwater contaminant of emerging concern for which bioremediation may become a practical remediation strategy. Therefore, it is important to advance our heuristic understanding of geochemical parameters that are most influential on the potential success of intrinsic bioremediation of dioxane-impacted sites. Here, Pearson's and Spearman's correlation and linear regression analyses were conducted to discern associations between 1,4-dioxane biodegradation activity measured in aerobic microcosms and groundwater geochemical parameters at four different contaminated sites. Dissolved oxygen, which is known to limit dioxane biodegradation, was excluded as a limiting factor in this analysis. Biodegradation activity was positively associated with dioxane concentrations (p < 0.01; R < 0.70) as well as the number of catabolic thmA gene copies (p < 0.01; R = 0.80) encoding dioxane monooxygenase. Thus, whereas environmental factors such as pH, temperature, and nutrients may influence dioxane biodegradation, these parameters did not exert as strong of an influence on potential biodegradation activity as the in situ concentration of substrate dioxane at the time of sampling. This analysis infers that aerobic sites with higher dioxane concentrations are more likely to select and sustain a thriving population of dioxane degraders, while sites with relatively low dioxane concentrations would be more difficult to attenuate naturally and may require alternative remediation strategies.
1,4-二恶烷（二恶烷）是一种地下水污染物，具有新兴关注的特性，生物修复可能成为一种实用的修复策略。因此，深入了解对 1,4-二恶烷污染场地的本底生物修复的潜在成功影响最大的地球化学参数非常重要。在这里，进行了 Pearson 和 Spearman 相关性和线性回归分析，以辨别在四个不同污染场地的好氧微宇宙中测量的 1,4-二恶烷生物降解活性与地下水地球化学参数之间的关联。已知限制二恶烷生物降解的溶解氧被排除在此分析的限制因素之外。生物降解活性与二恶烷浓度呈正相关（p<0.01；R<0.70），与编码二恶烷单加氧酶的 catabolic thmA 基因拷贝数也呈正相关（p<0.01；R=0.80）。因此，尽管环境因素（如 pH 值、温度和营养物质）可能会影响二恶烷的生物降解，但这些参数对潜在生物降解活性的影响不如采样时原位基质二恶烷浓度那么大。该分析推断，二恶烷浓度较高的好氧场地更有可能选择和维持大量的二恶烷降解菌，而二恶烷浓度相对较低的场地则更难以自然衰减，可能需要替代修复策略。
