Faculty of Earth Sciences, University of Iceland, Askja, Sturlugata 7, 101, Reykjavik, Iceland.
Department of Environmental Sciences, Agricultural University of Iceland, Hvanneyri, 311, Borgarnes, Iceland.
Environ Sci Pollut Res Int. 2014 Feb;21(3):1759-1768. doi: 10.1007/s11356-013-2069-z. Epub 2013 Aug 25.
Polychlorinated biphenyls (PCBs) pose a threat to the environment due to their high adsorption capacity to soil organic matter, stability and low reactivity, low water solubility, toxicity and ability to bioaccumulate. With Icelandic soils, research on contamination issues has been very limited and no data has been reported either on PCB degradation potential or rate. The goals of this research were to assess the bioavailability of aged PCBs in the soils of the old North Atlantic Treaty Organization facility in Keflavík, Iceland and to find the best biostimulation method to decrease the pollution. The effectiveness of different biostimulation additives (N fertiliser, white clover and pine needles) at different temperatures (10 and 30 °C) and oxygen levels (aerobic and anaerobic) were tested. PCB bioavailability to soil fauna was assessed with earthworms (Eisenia foetida). PCBs were bioavailable to earthworms (bioaccumulation factor 0.89 and 0.82 for earthworms in 12.5 ppm PCB soil and in 25 ppm PCB soil, respectively), with less chlorinated congeners showing higher bioaccumulation factors than highly chlorinated congeners. Biostimulation with pine needles at 10 °C under aerobic conditions resulted in nearly 38 % degradation of total PCBs after 2 months of incubation. Detection of the aerobic PCB degrading bphA gene supports the indigenous capability of the soils to aerobically degrade PCBs. Further research on field scale biostimulation trials with pine needles in cold environments is recommended in order to optimise the method for onsite remediation.
多氯联苯 (PCBs) 由于其对土壤有机质的高吸附能力、稳定性和低反应性、低水溶性、毒性和生物累积能力，对环境构成威胁。冰岛土壤的污染问题研究非常有限，也没有报告关于 PCB 降解潜力或速率的数据。本研究的目的是评估冰岛凯夫拉维克旧北大西洋公约组织设施土壤中老化 PCB 的生物利用度，并找到最佳的生物刺激方法来减少污染。不同生物刺激添加剂（氮肥、白三叶草和松针）在不同温度（10 和 30°C）和氧气水平（需氧和厌氧）下的有效性进行了测试。用蚯蚓（赤子爱胜蚓）评估了 PCB 对土壤动物区系的生物利用度。PCBs 对蚯蚓具有生物利用度（在 12.5 ppm PCB 土壤和 25 ppm PCB 土壤中，蚯蚓的生物积累因子分别为 0.89 和 0.82），低氯化同系物的生物积累因子高于高氯化同系物。在 10°C 下需氧条件下用松针进行生物刺激，在孵育 2 个月后，总 PCB 的降解率接近 38%。好氧 PCB 降解基因 bphA 的检测支持土壤具有好氧降解 PCB 的本土能力。建议在寒冷环境下进行现场规模的松针生物刺激试验，以优化原位修复方法。
