Fate of petrogenic hydrocarbons during phytoremediation of petroleum impacted soils

大量的污染物，包括石油碳氢化合物（PHC），已被释放到环境中。由于其在加拿大30，000多个已知地点的土壤中具有持久性，因此有必要开发具有成本效益和效率的补救技术。我们已经开发了一种植物生长促进根际细菌（PGPR）增强的植物修复系统（PEPS），是有效地降解土壤中的PHC。PEPS已成功地用于ON、AB、MB和QC的几个全规模现场试验。虽然我们已经表明，PHC可以在土壤中使用该系统降解，由于植物生长的植物源性疏水性材料的积累可以混淆的结果，标准的加拿大理事会的环境部长（CCME）分析所需的法规。在某种程度上，这是因为许多根衍生的化合物是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）分析等技术可以将成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，以评估事故后的责任PHC释放，但尚未应用于植物补救。应用GC/MS技术和风险评估可以提供校准通过CCME PHC分析获得的数据的基础，并将提供所需的方法来区分土壤样品中的植物源物质的PHC。拟议的研究的总体目标是表征和量化的疏水性化合物在土壤中的植物修复过程中，以区分产岩材料从植物材料，以更好地满足监管标准。这将通过比较种植的受影响区域与种植的未受影响对照区域的可浸提疏水材料和土壤毒性来完成。监测在植物补救过程中积累的植物源化合物的暂时出现，并说明它们在标准CCME PHC分析中的存在，将提高这种对环境负责的补救战略的可靠性，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.