Activated and nonactivated forms of zinc powder: Reactivity toward chlorocarbons in water and AFM studies of surface morphologies

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es970997e· OSTI ID:655405

Boronina, T N; Lagadic, I; Klabunde, K J ^[1]; Sergeev, G B ^[2]

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1. Kansas State Univ., Manhattan, KS (United States). Dept. of Chemistry
2. Lomonosov Moscow State Univ. (Russian Federation). Dept. of Chemistry

This work was carried out with the purpose of developing effective reagents for decontamination of groundwater contaminated with chlorocarbons. Zinc metal as a reducing agent for carbon tetrachloride (CT), chloroform (Chl), and methylene chloride (MC) in aqueous solution has been studied in some detail, especially regarding activated forms of the metal. Chlorocarbon concentrations were monitored at certain time intervals by gas chromatography/mass spectrometry (GC/MS) analysis of the headspace and water phase. Reaction mixture headspace was additionally studied by a GC/headspace analysis system to detect the formation of hydrocarbons. Chloroform, methylene chloride, methyl chloride, methane, and acetylene were found to be products from CT reduction. For methylene chloride reduction, traces of cis and trans-1,2-dichloroethene (DCE) were also found. Activated by cryo or mechanical treatment, metallic zinc caused an increase in CT dechlorination rate and conversion into methane. After the first 2.5 h, more than 20% of CT was converted into methane by cryochemically activated zinc in comparison to 1.2% by conventional zinc dust. Furthermore, CT reduction by activated zinc caused the formation of DCEs and TCE. Pathways are proposed to account for the observed methane/methylene chloride ratio and DCEs and TCE formation that include sequential reductive dechlorination through organometallic and carbonoid species on the Zn surface.

• OSTI ID: 655405
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 17 Vol. 32; ISSN 0013-936X; ISSN ESTHAG
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON TETRACHLORIDE
CHLOROFORM
GROUND WATER
METHYLENE CHLORIDE
REAGENTS
REMEDIAL ACTION
WATER CHEMISTRY
ZINC