This study presents an advance on the standard in situ reductive remediation technique using nanosized zero valent iron (NZVI). The initial process used a conventional form of NZVI, NANOFER 25 S (NANO IRON, s.r.o.), at a site contaminated with chlorinated hydrocarbons (CHC) in 2014. In 2018, levels of contamination at the site were still too high; hence, a second remediation intervention was performed using a cheaper form of NZVI, NANOFER STAR DC (NANO IRON, s.r.o.), accompanied with application of an electrical current (DC). The physical-chemical parameters at the site showed moderate reductive conditions for both techniques. While remediation with NANOFER 25 S showed a continuous decrease in NZVI activity over time, application of NANOFER STAR DC + DC resulted in a long-term reductive effect, observable as a persistent decrease in CHC concentration and evolution of ethene and ethane dechlorination products. NZVI in the STAR DC + DC was still active after around 200 days. Final efficiency of the STAR DC + DC method was calculated at 3.7 times higher than the conventional technique using NANOFER 25 S only. Laboratory-scale experiments confirmed the field observations, indicating the significantly elevated effectivity of STAR DC + DC.

本研究展示了使用纳米零价铁 (NZVI)的标准原位还原修复技术的进展。 2014 年，在一个受到氯化烃 (CHC) 污染的场地，最初的过程使用了传统形式的 NZVI，NANOFER 25 S（NANO IRON，sro）。 2018 年，该场地的污染水平仍然过高；因此，使用更便宜的 NZVI NANOFER STAR DC (NANO IRON, sro) 进行了第二次修复干预，同时施加了电流 (DC)。现场的物理化学参数显示两种技术的还原条件适中。使用 NANOFER 25 进行修复时 S 显示 NZVI 活性随时间持续降低，NANOFER STAR DC + DC 的应用导致长期还原效果，可观察到 CHC 浓度持续降低以及乙烯和乙烷脱氯产物的释放。大约 200 天后，STAR DC + DC 中的 NZVI 仍然活跃。STAR DC + DC 方法的最终效率计算为比 仅使用 NANOFER 25 S的传统技术高 3.7 倍。实验室规模的实验证实了现场观察结果，表明 STAR DC + DC 的有效性显着提高。