Degradation of Trichloroethene with a Novel Ball Milled Fe–C Nanocomposite

Abstract

Nanoscale zero-valent iron (NZVI) is effective in reductively degrading dense non-aqueous phase liquids (DNAPLs), such as trichloroethene (TCE), in groundwater (i.e., dechlorination) although the NZVI technology itself still suffers from high material costs and inability to target hydrophobic contaminants in source zones. To address these problems, we developed a novel, inexpensive iron-carbon (Fe-C) nanocomposite material by simultaneously milling micron-size iron and activated carbon powder. Microscopic and X-ray diffraction (XRD) characterization of the composite material revealed that nanoparticles of Fe were dispersed in activated carbon and a new iron carbide phase was formed. Bench-scale studies showed that this material instantaneously sorbed >90% of TCE from aqueous solutions and subsequently decomposed TCE into non-chlorinated products. Compared to milled Fe, Fe-C nanocomposite dechlorinated TCE at a slightly slower rate and favored the production of ethene over other TCE degradation products such as C3--C6 compounds. When placed in hexane-water mixture, the Fe-C nanocomposite materials are preferentially partitioned into the organic phase, indicating the ability of the composite materials to target DNAPL during remediation.

Effect of emplaced nZVI mass and groundwater velocity on PCE dechlorination and hydrogen evolution in water-saturated sand

“…However, the choice of support can affect this ratio. They found that this ratio varied from 3.25 to 7 for an Fe-C composite and Fe/carbon mixture, respectively [44]. It should be noted that the type of NZVI can also greatly affect this ratio.…”

“…This ratio appears to be relatively consistent for RNIP and modified RNIP for both PCE and TCE. Liu found and ethane to ethane ratio of 4 for TCE dechlorination by milled zerovalent iron [44]. However, the choice of support can affect this ratio.…”

Quantifying the efficiency and selectivity of organohalide dechlorination by zerovalent iron

“…Effect of forming composites with carbonaceous materials. Many carbonaceous materials have been used as supports for nZVI to form Fe-carbon composites, [71][72][73] including activated carbon (AC), hydrochar, carbon aerogel, mesoporous carbon, graphene, and biochar. The nZVI particles are dispersed within the carbon pore matrix to prevent aggregation and to enhance mobility in the subsurface when the size of the carbon particle falls into the colloidal range (e.g., 1-2 mm Carbo-Iron® 74 ).…”

Preparation and recovery of iron carbide from pyrite cinder using carburization-magnetic separation technology

“…Iron carbide is an attractive raw material for steelmaking, and it can also be used for magnetic recording medium, electromagnetic shielding materials, catalyst etc. [16,17], which possesses higher value-added than iron ore concentrate, sinter, pellet and sponge iron [18]. Several methods for the preparation of iron carbide were reported, such as reaction milling [19], sol-gel [20], laser pyrolysis [21], sonochemistry [22], alkalide reduction [23], chemical vapor condensation [24], and physical vapor deposition [25].…”

“…The thermodynamic data calculated using the FactSage software (Eqs. (7), (10), (13),(16) and(19)) indicates that Na 2 SO 4 is difficult to react with SiO 2 and Al 2 O 3 in the absence of CO and H 2 . When CO or H 2 is present, sodium modify reactions (Eqs.…”