The ZVI acts as a reducing agent to provide electrons directly to the contaminant for degradation or to support processes that require electrons to degrade contaminants. Zero-valent iron can provide an abiotic degradation pathway involving the direct reaction of ZVI with groundwater contaminants.
What are zero valent iron nanoparticles?
Zero-valent iron is inexpensive, non-toxic and a moderate reducing reagent (standard reduction potential E0 = −0.44 V). In presence of oxygen dissolved in water, zero-valent iron is capable to oxidize organic pollutants. In a first reaction, ZVI reacts with O2 to produce H2O2 (Equation (1)).
What are zero valent metals?
Zerovalent iron (ZVI) is the most commonly used zerovalent metal (ZVM) for environmental remediation. ZVI is typically applied as a reductant and is capable of transforming (degrading) or sequestering a variety of contaminants found in groundwater and soil.
Why are Group 18 elements called zero valent?
(a) Elements of group 18 have their outermost shell completely filled. So, they neither gain electron nor lose any electron and hence have zero valency. Thus, they are called zero valent.
Which metal center does not obey the 18-electron rule?
The counting of the 18 valence electrons in transition metal complexes may be obtained by following either of the two methods of electron counting, the first is – the ionic method and the second method is the neutral method. Thus, $V{(CO)_6}$ does not obey 18-electron rule as V has 17 electrons.
What is a zerovalent iron?
Zerovalent iron. Zerovalent iron and other zerovalent metals (ZVI and ZVM, respectively) have a variety of applications ranging from filters to electrodes to trenches. One of the emerging uses for ZVI is iron wall remediation.
What is nZVI (zero valent iron)?
Nanoscale zero-valent iron (NZVI) particles are typically 5–40 nm sized Fe0/Fe-oxide particles that rapidly transform many environmental contaminants to benign products and are a promising in situremediation agent.
How can zero-valent iron be used to remediate groundwater?
Zero-valent iron has been used successfully in the past to remediate groundwater by construction of a permeable reactive barrier (PRB) of zero-valent iron to intercept and dechlorinate chlorinated hydrocarbons such as trichloroethylene (TCE) in groundwater plumes.
Can nanoscale zero-valent iron eliminate the need for PRBs?
The use of nanoscale zero-valent iron (NZVI) instead of using micro/macro-scale Fe0 (zero- valent iron) materials could potentially eliminate the need for using PRBs and be more effective in both cost feasibility and contaminant remediation.
