Determination of biogeochemical processes in oil-contaminated aquifer using principal component analysis

作者：Lü Hang; Liu Mingyao; Su Xiaosi^*; Lin Guangyu

来源：Journal of Central South University(Science and Technology), 2013, 44(8): 3552-3560.

• Biodegradation process
• Biogeochemical process
• Contaminated aquifer
• Degradation products
• Electron-accepting process
• Environmental conditions
• Mineral dissolution
• Petroleum hydrocarbons

Three rounds of monitoring data were used to analyze the most important governing processes and their space distribution by principal component analysis. Five factors explaining most of the variability were extracted. Factor 1 is highly correlated with Mg2+, Ca2+, K+ and Cl-, which can be interpreted as the mineral dissolution factor. Factors 2-5 are all correlated with the petroleum hydrocarbons contaminants, degradation products (HCO3-), electron acceptors (such as SO42-) and indicators of environmental conditions (pH), indicating the occurrence of biodegradation processes, especially sulfate reduction, aerobic respiration and nitrate reduction, and the space distribution of the indicators above also confirms the reaction. On the other hand, the scores of Factor 2, which represent the biodegradation process, are positive in the core and upgradient of the contaminated plume and negative in the downgradient, which further confirm that from the core and upgradient of the contaminated plume to the the downgradient, the impact of biodegradation weakens and mineral dissolution strengthens. The principal component analysis can further explain the monitoring data, and it is a useful tool to study the biodegradation processes and identify the dominant terminal electron-accepting process in contaminated aquifers.

• 出版日期2013