Fate of petrogenic hydrocarbons during phytoremediation of petroleum impacted soils

包括石油碳氢化合物(PHC)在内的大量污染物被释放到环境中。它们在加拿大30,000个已知地点的土壤中的持久性要求开发具有成本效益和高效的修复技术。我们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)，该系统能够有效地降解土壤中的PHC。PEPS已在ON、AB、MB和QC的几个现场试验中成功使用。尽管我们已经证明，使用该系统可以在土壤中降解PHC，但由于植物生长而积累的植物源疏水物质可能会混淆加拿大环境部长委员会(CCME)法规要求的标准分析结果。在一定程度上，这是因为许多根衍生化合物是PHC成分的天然类似物。CCME支持的公认分析方案不区分岩性化合物和植物性化合物。气相色谱/质谱仪(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分析，以评估意外释放PHC后的风险，但尚未应用于植物修复。应用GC/MS技术和风险评估可以为校准通过CCME PHC分析获得的数据提供基础，并将为区分土壤样品中的PHC和植物来源物质提供必要的方法学。拟议研究的总体目标是在植物修复过程中表征和量化土壤中的疏水化合物，以区分成岩物质和成植物物质，以更好地满足监管标准。这将通过比较种植的受影响地区和种植的对照地区的可提取疏水物质和土壤毒性来实现。监测在植物修复过程中积累的植物源化合物的时间外观，并考虑到它们在CCME PHC标准分析中的存在，将提高这一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.