Ground Water and Ecosystems Restoration Division, National Risk Management Research Laboratory, Office of Research and Development, United States Environmental Protection Agency, 919 Kerr Research Drive, Ada, OK 74820, USA.
Water Res. 2012 Oct 15;46(16):5071-84. doi: 10.1016/j.watres.2012.06.051. Epub 2012 Jul 7.
A field test of emulsified zero valent iron (EZVI) nanoparticles was conducted at Parris Island, SC, USA and was monitored for two and half years to assess the treatment of subsurface-source zone chlorinated volatile organic compounds (CVOCs) dominated by tetrachloroethene (PCE) and its chlorinated daughter products. Two EZVI delivery methods were used: pneumatic injection and direct injection. In the pneumatic injection plot, 2180 L of EZVI containing 225 kg of iron (Toda RNIP-10DS), 856 kg of corn oil, and 22.5 kg of surfactant were injected to remedy an estimated 38 kg of CVOCs. In the direct injection plot, 572 L of EZVI were injected to treat an estimated 0.155 kg of CVOCs. After injection of the EZVI, significant reductions in PCE and trichloroethene (TCE) concentrations were observed in downgradient wells with corresponding increases in degradation products including significant increases in ethene. In the pneumatic injection plot, there were significant reductions in the downgradient groundwater mass flux values for PCE (>85%) and TCE (>85%) and a significant increase in the mass flux of ethene. There were significant reductions in total CVOC mass (86%); an estimated reduction of 63% in the sorbed and dissolved phases and 93% reduction in the PCE DNAPL mass. There are uncertainties in these estimates because DNAPL may have been mobilized during and after injection. Following injection, significant increases in dissolved sulfide, volatile fatty acids (VFA), and total organic carbon (TOC) were observed. In contrast, dissolved sulfate and pH decreased in many wells. The apparent effective remediation seems to have been accomplished by direct abiotic dechlorination by nanoiron followed by biological reductive dechlorination stimulated by the corn oil in the emulsion.
在美国南卡罗来纳州的帕里斯岛进行了乳化零价铁（EZVI）纳米颗粒的现场试验，监测了两年半的时间，以评估处理以四氯乙烯（PCE）及其氯化子产物为主的地下源区氯化挥发性有机化合物（CVOCs）的效果。使用了两种 EZVI 输送方法：气动注入和直接注入。在气动注入区域，注入了 2180 升含有 225 公斤铁（Toda RNIP-10DS）、856 公斤玉米油和 22.5 公斤表面活性剂的 EZVI，以修复估计 38 公斤的 CVOCs。在直接注入区域，注入了 572 升 EZVI，以处理估计 0.155 公斤的 CVOCs。在注入 EZVI 后，下游井中的 PCE 和三氯乙烯（TCE）浓度显著降低，降解产物相应增加，包括乙烯的显著增加。在气动注入区域，PCE（>85%）和 TCE（>85%）的地下水质量通量值显著降低，乙烯的质量通量显著增加。总 CVOC 质量（86%）显著减少；估计吸附相和溶解相减少 63%，PCE DNAPL 质量减少 93%。这些估计存在不确定性，因为 DNAPL 可能在注入期间和之后被动员。注入后，溶解的硫化物、挥发性脂肪酸（VFA）和总有机碳（TOC）显著增加。相比之下，许多井中的溶解硫酸盐和 pH 值下降。显然，有效的修复似乎是通过纳米铁的直接非生物脱氯，以及乳化剂中的玉米油刺激的生物还原脱氯来完成的。
