TY - JOUR
T1 - Degradation of 1,2,3-Trichloropropane (TCP)
T2 - Hydrolysis, elimination, and reduction by iron and zinc
AU - Sarathy, Vaishnavi
AU - Salter, Alexandra J.
AU - Nurmi, James T.
AU - Johnson, Graham O.Brien
AU - Johnson, Richard L.
AU - Tratnyek, Paul G.
PY - 2010/1/15
Y1 - 2010/1/15
N2 - 1,2,3-Trichloropropane (TCP) is an emerging contaminant because of increased recognition of its occurrence in groundwater, potential carcinogenicity, and resistance to natural attenuation. The physical and chemical properties of TCP make it difficult to remediate, with all conventional options being relatively slow or inefficient. Treatments that result in alkaline conditions (e.g., permeable reactive barriers containing zerovalent iron) favor base-catalyzed hydrolysis of TCP, but high temperature (e.g., conditions of in situ thermal remediation) is necessary for this reaction to be significant. Common reductants (sulfide, ferrous iron adsorbed to iron oxides, and most forms of construction-grade or nano-Fe0) produce insignificant rates of reductive dechlorination of TCP. Quantifiable rates of TCP reduction were obtained with several types of activated nano-Fe0, but the surface area normalized rate contants (kSA) for these reactions were lower than is generally considered useful for in situ remediation applications (10-4 L m-2 h-1). Much faster rates of degradation of TCP were obtained with granular Zn0, (k SA = 10-3 - 10-2 L m-2 h -1) and potentially problematic dechlorination intermediates (1,2- or 1,3-dichloropropane, 3-chloro-1-propene) were not detected. The advantages of Zn0 over Fe0 are somewhat peculiar to TCP and may suggest a practical application for Zn0 even though it has not found favor for remediation of contamination with other chlorinated solvents.
AB - 1,2,3-Trichloropropane (TCP) is an emerging contaminant because of increased recognition of its occurrence in groundwater, potential carcinogenicity, and resistance to natural attenuation. The physical and chemical properties of TCP make it difficult to remediate, with all conventional options being relatively slow or inefficient. Treatments that result in alkaline conditions (e.g., permeable reactive barriers containing zerovalent iron) favor base-catalyzed hydrolysis of TCP, but high temperature (e.g., conditions of in situ thermal remediation) is necessary for this reaction to be significant. Common reductants (sulfide, ferrous iron adsorbed to iron oxides, and most forms of construction-grade or nano-Fe0) produce insignificant rates of reductive dechlorination of TCP. Quantifiable rates of TCP reduction were obtained with several types of activated nano-Fe0, but the surface area normalized rate contants (kSA) for these reactions were lower than is generally considered useful for in situ remediation applications (10-4 L m-2 h-1). Much faster rates of degradation of TCP were obtained with granular Zn0, (k SA = 10-3 - 10-2 L m-2 h -1) and potentially problematic dechlorination intermediates (1,2- or 1,3-dichloropropane, 3-chloro-1-propene) were not detected. The advantages of Zn0 over Fe0 are somewhat peculiar to TCP and may suggest a practical application for Zn0 even though it has not found favor for remediation of contamination with other chlorinated solvents.
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U2 - 10.1021/es902595j
DO - 10.1021/es902595j
M3 - Article
C2 - 20000732
AN - SCOPUS:74949139260
SN - 0013-936X
VL - 44
SP - 787
EP - 793
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 2
ER -