Trichloroethylene
Dotaz
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- Klíčová slova
- TRICHLOROETHYLENE/metabolism *,
- MeSH
- lidé MeSH
- metabolická inaktivace * MeSH
- trichlorethylen metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- trichlorethylen MeSH
Nitriding has been used for decades to improve the corrosion resistance of iron and steel materials. Moreover, iron nitrides (FexN) have been shown to give an outstanding catalytic performance in a wide range of applications. We demonstrate that nitriding also substantially enhances the reactivity of zerovalent iron nanoparticles (nZVI) used for groundwater remediation, alongside reducing particle corrosion. Two different types of FexN nanoparticles were synthesized by passing gaseous NH3/N2 mixtures over pristine nZVI at elevated temperatures. The resulting particles were composed mostly of face-centered cubic (γ'-Fe4N) and hexagonal close-packed (ε-Fe2-3N) arrangements. Nitriding was found to increase the particles' water contact angle and surface availability of iron in reduced forms. The two types of FexN nanoparticles showed a 20- and 5-fold increase in the trichloroethylene (TCE) dechlorination rate, compared to pristine nZVI, and about a 3-fold reduction in the hydrogen evolution rate. This was related to a low energy barrier of 27.0 kJ mol-1 for the first dechlorination step of TCE on the γ'-Fe4N(001) surface, as revealed by density functional theory calculations with an implicit solvation model. TCE dechlorination experiments with aged particles showed that the γ'-Fe4N nanoparticles retained high reactivity even after three months of aging. This combined theoretical-experimental study shows that FexN nanoparticles represent a new and potentially important tool for TCE dechlorination.
- Klíčová slova
- Dechlorination, Groundwater remediation, Iron nitride, Molecular modeling, Nanoparticles, Selectivity, Trichloroethylene, Zerovalent iron,
- MeSH
- chemické látky znečišťující vodu * MeSH
- nanočástice * MeSH
- podzemní voda * MeSH
- trichlorethylen * MeSH
- železo MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chemické látky znečišťující vodu * MeSH
- trichlorethylen * MeSH
- železo MeSH
- Klíčová slova
- ANESTHESIA *, DENTISTRY *, TRICHLOROETHYLENE *,
- MeSH
- anestezie * MeSH
- anesteziologie * MeSH
- trichlorethylen * MeSH
- zubní lékařství * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- trichlorethylen * MeSH
The toxicity of trichloroethylene was tested in both glass enclosures and in polystyrene immunological plates, and resulted in insignificant correlation of EC₅₀ (evaluated as OD 750 nm). In enclosures, EC₅₀ evaluated as O₂ evolution and as pH increment was highly significant. The optimal time for the assay of TCE in enclosures was 48-72 h; and in plates ca 200 h. After a longer time (e.g. 300 h) TCE diffused from the plates and growth was revived. TCE in low concentrations (ca. 0.1-0.2 g/L) stimulated the growth of some tested organisms, both in plates and in enclosures. Toxicity occurred from ca. 0.35-0.6 g/L (EC₅₀). The testing procedure in enclosures was a suitable method for some volatile substances, giving rapid results.
- MeSH
- chemické látky znečišťující vodu toxicita MeSH
- Chlorophyta účinky léků MeSH
- fotosyntéza účinky léků MeSH
- koncentrace vodíkových iontů MeSH
- sinice účinky léků MeSH
- trichlorethylen toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chemické látky znečišťující vodu MeSH
- trichlorethylen MeSH
- Klíčová slova
- AIR POLLUTION *, POISONING *, TOXICOLOGIC REPORT *, TRICHLOROETHYLENE *,
- MeSH
- otrava * MeSH
- toxikologie * MeSH
- trichlorethylen * MeSH
- znečištění ovzduší * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- trichlorethylen * MeSH
- Klíčová slova
- AIR POLLUTION *, TRICHLOROETHYLENE *,
- MeSH
- trichlorethylen * MeSH
- znečištění ovzduší * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- trichlorethylen * MeSH
- Klíčová slova
- ALCOHOL, ETHYL/related compounds *, CEREBRAL CORTEX/pharmacology *, SPINAL CORD/pharmacology *, TRICHLOROETHYLENE/pharmacology *,
- MeSH
- ethanol analogy a deriváty MeSH
- ethylenchlorhydrin * MeSH
- mícha farmakologie MeSH
- mozková kůra farmakologie MeSH
- reflex * MeSH
- trichlorethylen farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 2,2,2-trichloroethanol MeSH Prohlížeč
- ethanol MeSH
- ethylenchlorhydrin * MeSH
- trichlorethylen MeSH
Zero-valent iron nanoparticles (nZVI) treated by reduced sulfur compounds (i.e., sulfidated nZVI, S-nZVI) have attracted increased attention as promising materials for environmental remediation. While the preparation of S-nZVI and its reactions with various groundwater contaminants such as trichloroethylene (TCE) were already a subject of several studies, nanoparticle synthesis procedures investigated so far were suited mainly for laboratory-scale preparation with only a limited possibility of easy and cost-effective large-scale production and FeS shell property control. This study presents a novel approach for synthesizing S-nZVI using commercially available nZVI particles that are treated with sodium sulfide in a concentrated slurry. This leads to S-nZVI particles that do not contain hazardous boron residues and can be easily prepared off-site. The resulting S-nZVI exhibits a core-shell structure where zero-valent iron is the dominant phase in the core, while the shell contains mostly amorphous iron sulfides. The average FeS shell thickness can be controlled by the applied sulfide concentration. Up to a 12-fold increase in the TCE removal and a 7-fold increase in the electron efficiency were observed upon amending nZVI with sulfide. Although the FeS shell thickness correlated with surface-area-normalized TCE removal rates, sulfidation negatively impacted the particle surface area, resulting in an optimal FeS shell thickness of approximately 7.3 nm. This corresponded to a particle S/Fe mass ratio of 0.0195. At all sulfide doses, the TCE degradation products were only fully dechlorinated hydrocarbons. Moreover, a nearly 100% chlorine balance was found at the end of the experiments, further confirming complete TCE degradation and the absence of chlorinated transformation products. The newly synthesized S-nZVI particles thus represent a promising remedial agent applicable at sites contaminated with TCE.
- Klíčová slova
- dechlorination, nanoparticles, selectivity, sulfidation, trichloroethylene, zero-valent iron,
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- RESPIRATION *, TRICHLOROETHYLENE/determination *,
- MeSH
- buněčné dýchání * MeSH
- dýchání * MeSH
- lidé MeSH
- tělesné tekutiny * MeSH
- trichlorethylen analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- trichlorethylen MeSH
- Klíčová slova
- TRICHLOROETHYLENE/metabolism *,
- MeSH
- biologický transport MeSH
- lidé MeSH
- metabolická inaktivace * MeSH
- trichlorethylen metabolismus MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- trichlorethylen MeSH
