Toxicity of soil-dwelling organisms to nZVI

纳米零价铁(NZVI)在修复土壤污染物方面具有巨大的潜力，特别是对微生物降解或风化具有顽固性的有机化合物。然而，尚未对加拿大本土的土壤生物进行nZVI毒性的风险评估；这一知识是确保补救措施不会造成伤害所必需的。由于修复活动，蚯蚓、植物和无脊椎动物等土壤生物可能会暴露在nZVI中，而且由于其体积较小，土壤中的厌氧细菌也可能受到显著影响。使用加拿大环境和气候变化委员会(ECCC)制定的议定书确定nZVI对土壤栖息生物的毒性阈值，将使加拿大在这一领域处于领先地位，并允许就与受污染场地相关的法规作出知情决定。这类网站的数量很多，包括由该公司管理的活跃和遗留网站，以及被遗弃和孤立的网站。这是拟议工作的第一个目标。拟议工作的第二个目标是将这些毒性阈值表示为土壤中nZVI的测量浓度，而不是名义浓度，这需要适应和验证现有的水体系检测方法。

Nano zero-valent iron (nZVI) has great potential for remediation of soil contaminants, particularly organiccompounds that are recalcitrant to microbial degradation or weathering. However, risk assessments of nZVItoxicity to soil dwelling organisms native to Canada have yet to be conducted; this knowledge is required toensure that the remediation doesn't cause harm. Soil organisms such as earthworms, plants, and invertebratesmay be exposed to nZVI as a result of remediation activities, and due to its small size, anaerobic bacteria in thesoil may also be impacted significantly. Determining the toxicity thresholds for nZVI to soil dwellingorganisms using protocols developed by Environment and Climate Change Canada (ECCC) would allowCanada to adopt the lead position in this field and allow for informed decisions to be made concerningregulations relevant to contaminated sites. Such sites are vast in number including active and legacy sites thatare being managed by the company, as well as abandoned and orphaned sites. This is the first objective of theproposed work. The second objective of the proposed work is to express these toxicity thresholds as measuredconcentration of nZVI in soil rather than nominal, requiring the adaptation and validation of existing detectionmethods for aqueous systems.