Fate of petrogenic hydrocarbons during phytoremediation of petroleum impacted soils

包括石油烃（PHC）在内的大量污染物已被释放到环境中。它们在加拿大大约30万个已知地点的土壤中持续存在，需要开发具有成本效益和效率的修复技术。我们开发了一种促进植物生长的根瘤菌（PGPR）增强植物修复系统（PEPS），可以有效地降解土壤中的PHC。PEPS已成功地在ON、AB、MB和QC的几次全尺寸现场试验中使用。虽然我们已经证明PHC可以在使用该系统的土壤中降解，但由于植物生长而积累的植物性疏水物质可能会混淆法规要求的标准加拿大环境部长理事会（CCME）分析结果。在某种程度上，这是因为许多根源化合物是PHC成分的天然类似物。CCME支持的公认分析方案不区分岩源化合物和植物源化合物。气相色谱/质谱（GC/MS）分析等技术可以将产岩物质与其他有机化合物区分开来。这些方法已被用于化学指纹鉴定，以评估PHC意外释放后的责任，但尚未应用于植物修复。GC/MS技术的应用和风险评估可以为CCME PHC分析获得的校准数据提供基础，并将为区分土壤样品中的PHC和植物性物质提供必要的方法。本研究的总体目标是表征和量化植物修复过程中土壤中的疏水化合物，以区分岩石物质和植物物质，以更好地满足监管标准。这将通过比较种植受影响地区与种植未受影响对照地区的可提取疏水物质和土壤毒性来完成。监测植物修复过程中积累的植物性化合物的时间外观，并在标准CCME PHC分析中说明它们的存在，将提高这种对环境负责的补救策略的可靠性，并促进其在更广泛的受影响地点的使用。

Large amounts of contaminants, including petroleum hydrocarbons (PHC), have been released into the environment. Their persistence in soils at > 30,000 known sites in Canada necessitates the development of cost effective and efficient remediation technologies. We have developed a plant growth promoting rhizobacteria (PGPR) enhanced phytoremediation system (PEPS) that is effective at degrading PHC in soils. PEPS has been successfully used in several full scale field trials in ON, AB, MB and QC. Although we have shown that PHC can be degraded in soils using this system, accumulation of phytogenic hydrophobic material due to plant growth can confound the results of standard Canadian Council of Ministers of the Environment (CCME) analyses required by regulations. In part, this is because many root-derived compounds are natural analogs of PHC constituents. Accepted analytical protocols supported by CCME do not distinguish between petrogenic and phytogenic compounds. Techniques such as gas chromatography/mass spectrometry (GC/MS) analyses can distinguish petrogenic materials from other organic compounds. These methods have been used for chemical fingerprinting to assess liability after accidental PHC releases, but have not been applied to phytoremediation. Application of GC/MS techniques and risk assessment can provide the basis for calibrating data obtained via the CCME PHC analyses, and will provide the needed methodologies for distinguishing PHC from phytogenic materials in soil samples. The overall goal of the proposed research is to characterize and quantify the hydrophobic compounds in soil during the course of phytoremediation to distinguish petrogenic material from phytogenic material to better meet regulatory standards. This will be done by comparing the extractable hydrophobic material and soil toxicity of planted impacted areas to planted unimpacted control areas. Monitoring the temporal appearance of phytogenic compounds that accumulate during phytoremediation, and accounting for their presence in standard CCME PHC analyses, would enhance the reliability of this environmentally responsible remedial strategy and facilitate its use at a broader range of impacted sites.