Toxicity of soil-dwelling organisms to nZVI

纳米零价铁（nZVI）在修复土壤污染物，特别是难降解有机物方面具有巨大的潜力。然而，尚未对nZVI对加拿大本土土壤生物的毒性进行风险评估;需要了解这方面的知识，以确保补救措施不会造成伤害。土壤生物，如蚯蚓、植物和无脊椎动物可能会因补救活动而暴露于零价铁，由于其体积小，土壤中的厌氧细菌也可能受到显著影响。利用加拿大环境和气候变化委员会制定的议定书确定nZVI对土壤生物的毒性阈值，将使加拿大能够在这一领域采取领先地位，并就与受污染场地有关的法规作出知情决定。这些网站数量庞大，包括由公司管理的活动和遗留网站，以及废弃和孤儿网站。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的实测浓度，而不是标称浓度，这需要对现有的含水系统检测方法进行调整和验证。

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.