This paper describes the results of the first field-scale demonstration conducted to evaluate the performance of nanoscale emulsified zero-valent iron (EZVI) injected into the saturated zone to enhance in situ dehalogenation of dense, nonaqueous phase liquids (DNAPLs) containing trichloroethene (TCE). EZVI is an innovative and emerging remediation technology. EZVI is a surfactant-stabilized, bi...

BACKGROUND In a world of nanotechnology, the first concern is the potential environmental impact of nanoparticles. An efficient way to estimate nanotoxicity is to monitor the responses of bacteria exposed to these particles. OBJECTIVES The current study explored the antimicrobial properties of nZVI (zero-valent Iron nanoparticles) on the Gram-negative bacterial systems Erwinia amylovora, Xant...

Permeable reactive barriers (PRBs) composed of zero-valent iron (ZVI) are susceptible to passivation, resulting in substantially decreased rates of chlorinated solvent removal over time. In this study, the application of low electrical direct current (DC) to restore the reductive capacity of passivated ZVI was examined. Electrical current was applied to a laboratory column reactor filled with a...

Granular zero-valent iron (ZVI) has been widely used to construct permeable reactive barriers (PRB) for the in situ remediation of groundwater contaminated with halogenated hydrocarbons. In the anaerobic condition of most groundwater flow systems, iron undergoes corrosion by water and results in hydrogen gas generation. Several studies have shown that some of the hydrogen gas generated at the i...

Zero-valent iron nanoparticles (nano-Fe0) in aqueous solution rapidly inactivated Escherichia coli. A strong bactericidal effect of nano-Fe0 was found under deaerated conditions, with a linear correlation between log inactivation and nano-Fe0 dose (0.82 log inactivation/mg/L nano-Fe0 x h). The inactivation of E. coli under air saturation required much higher nano-Fe0 doses due to the corrosion ...

Zero-valent iron (Fe0)-based permeable reactive barrier treatment has been generating great interest for passive groundwater remediation, yet few studies have paid particular attention to the microbial activity and characteristics within and in the vicinity of the Fe0-barrier matrix. The present study was undertaken to evaluate the microbial population and community composition in the reducing ...

A study of alternative chromium reduction methods was performed for wastewater or contaminated water. Two existing chromium reduction treatment methods were tested on the wastewater samples: treatment with (1) zero-valent iron, and (2) bacteria cultures. We found that both methods can reduce chrome. However, the chrome reduction process using bacteria is considerably slower than that using iron...

Nanoscale zero-valent iron (NZVI) particles have been used for the remediation of a wide variety of contaminants. NZVI particles have high reactivity because of high reactive surface area. In this study, NZVI slurry was successfully used for phosphate removal and recovery. Batch studies conducted using different concentrations of phosphate (1, 5, and 10 mg PO4 -P/L with 400 mg NZVI/L) removed *...

Steroidal estrogens are one of the most challenging classes of hazardous contaminants as they can cause adverse effects to biota in extremely low concentrations. They emerge in both waste waters and surface waters serving as a source of drinking water. Environmental Quality Standards for 17β-estradiol (E2) and 17α-ethinylestradiol (EE2), promulgated within the EU Water Framework Directive, are ...

Nanoscale Zero Valent Iron (nZVI) represents a promising material for subsurface water remediation technology. However, dry, bare nZVI particles are highly reactive, being pyrophoric when they are in contact with air. The current trends of nZVI manufacturing lead to the surface passivation of dry nZVI particles with a thin oxide layer, which entails a decrease in their reactivity. In this work ...