Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, SA, Australia.
Biodegradation. 2012 Nov;23(6):881-95. doi: 10.1007/s10532-012-9580-7. Epub 2012 Aug 17.
This study evaluated the potential of monitored natural attenuation (MNA) as a remedial option for groundwater at a long-term petroleum hydrocarbon contaminated site in Australia. Source characterization revealed that total petroleum hydrocarbons (TPH) as the major contaminant of concern in the smear zone and groundwater. Multiple lines of evidence involving the geochemical parameters, microbiological analysis, data modelling and compound-specific stable carbon isotope analysis all demonstrated natural attenuation of hydrocarbons occurring in the groundwater via intrinsic biodegradation. Groundwater monitoring data by Mann-Kendall trend analysis using properly designed and installed groundwater monitoring wells shows the plume is stable and neither expanding nor shrinking. The reason for stable plume is due to the presence of both active source and natural attenuation on the edge of the plume. Assuming no retardation and no degradation the contaminated plume would have travelled a distance of 1,096 m (best case) to 11,496 m (worst case) in 30 years. However, the plume was extended only up to about 170 m from its source. The results of these investigations provide strong scientific evidence for natural attenuation of TPH in this contaminated aquifer. Therefore, MNA can be applied as a defensible management option for this site following significant reduction of TPH in the source zone.
本研究评估了监控自然衰减（MNA）作为澳大利亚一个长期受石油烃污染场地地下水修复选择的潜力。源特征描述表明，总石油烃（TPH）是污染带和地下水中主要关注的污染物。涉及地球化学参数、微生物分析、数据建模和特定化合物稳定碳同位素分析的多种证据均表明，地下水中的烃类通过内在生物降解发生自然衰减。通过使用经过适当设计和安装的地下水监测井进行曼恩-肯德尔趋势分析的地下水监测数据表明，羽流是稳定的，既不扩张也不收缩。羽流稳定的原因是羽流边缘既有活跃的源，也有自然衰减。假设没有阻滞和降解，受污染的羽流将在 30 年内（最佳情况）移动 1096 米（最坏情况）至 11496 米。然而，羽流仅从其源头延伸了约 170 米。这些调查结果为受污染含水层中 TPH 的自然衰减提供了强有力的科学证据。因此，在源区 TPH 大量减少后，MNA 可作为该场地的一种合理管理选择。
