Nanotechnology and in situ remediation: a review of the benefits and potential risks

Abstract

Objective: Although industrial sectors involving semiconductors; memory and storage technologies; display, optical, and photonic technologies; energy; biotechnology; and health care produce the most products that contain nanomaterials, nanotechnology is also used as an environmental technology to protect the environment through pollution prevention, treatment, and cleanup. In this review, we focus on environmental cleanup and provide a background and overview of current practice; research findings; societal issues; potential environment, health, and safety implications; and future directions for nanoremediation. We do not present an exhaustive review of chemistry/engineering methods of the technology but rather an introduction and summary of the applications of nanotechnology in remediation. We also discuss nanoscale zerovalent iron in detail.

Data sources: We searched the Web of Science for research studies and accessed recent publicly available reports from the U.S. Environmental Protection Agency and other agencies and organizations that addressed the applications and implications associated with nanoremediation techniques. We also conducted personal interviews with practitioners about specific site remediations.

Data synthesis: We aggregated information from 45 sites, a representative portion of the total projects under way, to show nanomaterials used, types of pollutants addressed, and organizations responsible for each site.

Conclusions: Nanoremediation has the potential not only to reduce the overall costs of cleaning up large-scale contaminated sites but also to reduce cleanup time, eliminate the need for treatment and disposal of contaminated soil, and reduce some contaminant concentrations to near zero-all in situ. Proper evaluation of nanoremediation, particularly full-scale ecosystem-wide studies, needs to be conducted to prevent any potential adverse environmental impacts.

Keywords: environmental implications; environmental technology; hazardous wastes; nano-remediation; nanotechnology; pollutants; remediation; toxicity; waste sites; zerovalent iron.

Figure 1

Estimated number (%) of U.S. hazardous waste sites (A) and estimated cleanup costs [billions US$ (percent of total)] for 2004–2033 (B). UST, underground storage tanks. Adapted from U.S. EPA (2004).

Figure 2

Map of remediation sites listed in Supplemental Material, Table 2 (doi:10.1289/ehp.0900793.S1) (Project on Emerging Nanotechnologies 2009).

Figure 3

Type of nanoparticles used (A) and type of media treated (B) at sites listed in Supplemental Material, Table 2 (doi:10.1289/ehp.0900793.S1).