Application of Zero-valent Iron Nanoparticles for Environmental Clean Up - Advanced Materials for Agriculture, Food and Environmental Safety - page 411

h e increasing concern over safe use of nanoparticles demands:
(i) development of rapid analytical tools and methods to detect their pres-
ence in dif erent environmental compartments, (ii) monitoring their pro-
duction, usage, release and disposal, and (iii) adequate models for toxicity
testing and risk analysis.

14.7.2 Fate and Behavior in Environment

Nanoparticles hold enormous potential to change many aspects of our
existence, some for the better and some for the worse. In other words,
nanoparticles have a Janus face. h e very properties which are exploited
for numerous benei cial applications could also produce unpredictable
ecotoxicological ef ects. For example, the toxic property of nanoparticles
on one hand could be utilized for the purpose of water disinfection, on the
other hand the same property could be harmful to the microbial commu-
nity when nanoparticles enter environment. Similarly, their high catalytic
property is of great signii cance for ef ective degradation of pollutants, but
the same property could induce toxic responses when taken up by a cell
[13]. When nFe 0 is introduced in a system (soil, sediment, groundwater,
aquifer) with an aim of degrading a contaminant, it not only interacts
with the contaminant but also with the biotic component of that system.
As the safety of nFe 0 is uncertain till date, it is important to consider its
at ermath in order to decide its fate. A proper understanding of mobil-
ity, bioavailability, toxicity and persistence of nFe 0 in the environment is
needed for assessing its risks. Additionally, several factors such as oxida-
tion and aging, interaction with common cations, ligands and complexes,
surface coating with humic acids, etc., play an important role in control-
ling the fate and behavior of nFe 0 in the environment, and thus need to be
studied in detail.

14.8 Concluding Remarks

h is chapter presents an overall perspective of nFe 0 to decipher potential
issues related to its application for remediation of sites contaminated with
toxic/hazardous pollutants. As evident from numerous studies, nFe 0 has the
potential ability to degrade or transform a wide array of contaminants to
nontoxic or less toxic form through reduction, adsorption and precipitation/
co-precipitation. Although nFe 0 has gained signii cant achievements in the
area of environmental clean up at both bench and i eld scales, there are still
a few grey areas, economic hurdles and unforeseen ecological threats which