Theoretically, sequential cycles of dechlorination followed by aerobic bio-oxidation are desirable to achieve complete degradation of a mixture of higher and lower chlorinated PCBs. In this research, soil was artificially contaminated with polychlorinated biphenyls (PCBs) in mixture and as single congeners, aged, and planted with two different plant species. Alternating redox cycles were created in the root zone of plants by flooding and draining the soil. Over 32 weeks, switchgrass (Panicum virgatum) and poplar (Populus deltoids x nigra DN34) planted systems that were exposed to alternate cycles of flooding performed better in reducing parent PCBs than planted systems that were not cycled (p<0.05). The cycled systems also had a higher mass of PCB transformation products than the uncycled systems. Multiple cycles were necessary to achieve significant differences between the cycled and uncycled treatments.

中文翻译：

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根际氧化还原循环及其对选定多氯联苯 (PCB) 同系物根际生物转化的影响

从理论上讲，脱氯和有氧生物氧化的连续循环对于实现高氯化和低氯化 PCB 混合物的完全降解是可取的。在这项研究中，土壤被混合和作为单一同源物的多氯联苯 (PCB) 人为污染，老化并种植了两种不同的植物物种。通过淹没和排水土壤，在植物的根区产生交替的氧化还原循环。在 32 周内，暴露于交替洪水循环的柳枝稷（Panicum virgatum）和杨树（Populus deltoids x nigra DN34）种植系统在减少亲本 PCB 方面的表现优于未循环的种植系统（p<0.05）。循环系统的 PCB 转换产品质量也高于非循环系统。