Toxicity of NZVI to Soil-Dwelling Organisms: Measuring Dose in Soils

将纳米工程材料添加到布朗菲尔德土壤中进行修复需要考虑这些材料相对于被修复污染物的环境风险。纳米零价铁颗粒（nZVI）作为土壤修复方法已经使用了十多年，用于降解或消除有机和无机土壤污染物、卤代有机化合物、多环芳烃、农药和重金属。限制其在安大略更广泛的使用，是有很少的知识theenvironmental影响的使用nZVI对土壤生态系统。由于与纳米颗粒相关的独特性质以及将nZVI应用于土壤作为修复手段，必须进行环境风险评估。然而，任何形成或转化的物质都有可能在环境中持久存在，可能导致生物累积，并对生活在土壤中的微生物和生物体产生毒性。迄今为止，土壤中的nZVI特性很差，其障碍在于高质量的毒性研究必须报告测量浓度而不是标称暴露浓度，并且复杂介质中定量nZVI的方法尚未建立。有许多显微镜和光谱方法可以检测nZVI，更大的挑战是定量（Shi et al.，2015）。一旦建立了定量能力，就可以确定各种表面活性剂对市售形式的nZVI的生态毒性的影响。用于测量nZVI的方法，在这项研究中应用的是核磁共振（NMR），和化学氧化还原探针靛蓝二磺酸盐（I2S）。这些将用于测量土壤孔隙水中的NZVI，通过离心从实验介质中提取。对加拿大的好处是，尚未对nZVI对加拿大特有的土壤栖息生物的毒性进行战略风险评估。蚯蚓、植物和无脊椎动物等土壤有机体可能会暴露于nZVI，由于其体积小，土壤中的厌氧细菌也可能受到显着影响。这种调查将使加拿大在这一领域处于领先地位，并允许就法规作出知情决定

Adding nanoengineered materials to brownfield soils for remediation would need to consider theenvironmental risks posed by these materials relative to the risks of the contaminant that is being remediated.Nano Zero-Valent Iron Particles (nZVI) have been used as a soil remediation method for more than a decade todegrade or immobilize organic and inorganic soil contaminants, halogenated organic compounds, PAHs,pesticides and heavy metals. The limitation to its broader use in Ontario, is that there is little knowledge of theenvironmental impact of the use of nZVI on soil ecosystems. Due to the unique properties associated withnanoparticles and the application of nZVI to soil as a means of remediation, environmental risk assessmentsmust be performed. However, there is potential for persistence in the environment of any formed ortransformed material, bioaccumulation, and toxicity to microbes and organisms living in the soil could result.So far, this is poorly characterized for nZVI in soils, the barrier to which is that high quality toxicity studiesmust report measured rather than nominal exposure concentrations, and methods for quantifying nZVI incomplex media are not well established. There are a number of microscopic and spectroscopic methods thatcan detect nZVI, the bigger challenge is quantification (Shi et al., 2015). Once capacity for quantification areestablished, the effect on ecotoxicity of the various surfactants on commercially available forms of nZVI can beidentified. The methodologies for measuring nZVI, to be applied in this study are Nuclear Magnetic Resonance(NMR), and the chemical redox probe indigo disulphonate (I2S). These will be used to measure NZVI in soilpore water, extracted from the experimental media by centrifugation. The benefit to Canada is that strategicrisk assessments of nZVI toxicity to soil dwelling organisms specific to Canada have yet to be conducted. Soilorganisms such as earthworms, plants, and invertebrates may be exposed to nZVI, and due to its small size,anaerobic bacteria in the soil may also be impacted significantly. Such investigation would allow Canada toadopt the lead position in this field and allow for informed decisions to be made concerning regulations