Sustainable environmental remediation using nZVI by managing lifecycle benefit-risk tradeoffs

Ensuring the sustainable development and use of NZVI for in situ remediation requires the incorporation of a multitude of factors and criteria, including those related to technology performance, cost, potential impacts to the environment and human health, as well as ethical, social, and legal concerns. This chapter provides an overview of these factors in order to help guide the sustainable development of NZVI. Among other main results, we find that while there are promising findings regarding its performance and effectiveness as a remediation technique, there are also growing concerns regarding its impacts to the environment and health. To date, most of this research has focused on the potential (eco)toxicological effects of NZVI with limited research on broader issues such as social or ethical implications. In fact, the social implications of NZVI, including the ability for a range of stakeholders and members of the public to be active participants in decision-making processes, have either been minimal or nonexistent. We also find that marketplace limitations appear to be serious obstacles to ensuring the sustainable development and use of NZVI as an environmental remediation technology, including questions pertaining to the validity of its cost-competitiveness. In order to balance the potential benefits, risks, and uncertainty characteristics of NZVI, there are a number of decision support frameworks and risk analysis tools which may be applied, including multi-criteria decision analysis, life cycle assessment, as well as diverse risk characterization or screening tools (e.g., NanoRiskCat). While several of these frameworks and tools may be suited for NZVI in theory, very few of them have been applied to NZVI in practice. In conclusion, these results indicate that while NZVI has potential to reduce environmental contaminants through in situ remediation, its development and use, particularly at field-scale sites, has not proceeded in the most sustainable manner possible thus far. In light of this, we provide specific recommendations to help ensure the sustainable development and use of NZVI, including recommendations specific for diverse stakeholder groups such as researchers, academics, industry, and government officials.