TY - JOUR
T1 - Chelate-modified fenton reaction for the degradation of trichloroethylene in aqueous and two-phase systems
AU - Lewis, Scott
AU - Lynch, Andrew
AU - Bachas, Leonidas
AU - Hampson, Steve
AU - Ormsbee, Lindell
AU - Bhattacharyya, Dibakar
PY - 2009/4/1
Y1 - 2009/4/1
N2 - The primary objective of this research was to model and understand the chelate-modified Fenton reaction for the destruction of trichloroethylene (TCE) present in both the aqueous and organic (in the form of droplets) phases. The addition of a nontoxic chelate (L), such as citrate or gluconic acid, allows for operation at near-neutral pH and controlled release of Fe(II)/Fe(III). For the standard Fenton reaction at low pH in two-phase systems, an optimum H 2O 2:Fe(II) molar ratio was found to be between 1:1 and 2:1. Experimentation proved the chelate-modified Fenton reaction effectively dechlorinated TCE in both the aqueous and organic phases at pH 6-7 using low H 2O 2:Fe(II) molar ratios (4:1 to 8:1). Increasing the L:Fe ratio was found to decrease the rate of H 2O 2 degradation in both Fe(II) and Fe(III) systems at near-neutral pH. Generalized models were developed to predict the concentration of TCE in the aqueous phase and TCE droplet radius as a function of time using literature-reported hydroxyl radical reaction kinetics and mass transfer relationships. Additional aspects of this work include the reusability of the Fe-citrate complex under repeated H 2O 2 injections in real water systems as well as packed column studies for simulated groundwater injection.
AB - The primary objective of this research was to model and understand the chelate-modified Fenton reaction for the destruction of trichloroethylene (TCE) present in both the aqueous and organic (in the form of droplets) phases. The addition of a nontoxic chelate (L), such as citrate or gluconic acid, allows for operation at near-neutral pH and controlled release of Fe(II)/Fe(III). For the standard Fenton reaction at low pH in two-phase systems, an optimum H 2O 2:Fe(II) molar ratio was found to be between 1:1 and 2:1. Experimentation proved the chelate-modified Fenton reaction effectively dechlorinated TCE in both the aqueous and organic phases at pH 6-7 using low H 2O 2:Fe(II) molar ratios (4:1 to 8:1). Increasing the L:Fe ratio was found to decrease the rate of H 2O 2 degradation in both Fe(II) and Fe(III) systems at near-neutral pH. Generalized models were developed to predict the concentration of TCE in the aqueous phase and TCE droplet radius as a function of time using literature-reported hydroxyl radical reaction kinetics and mass transfer relationships. Additional aspects of this work include the reusability of the Fe-citrate complex under repeated H 2O 2 injections in real water systems as well as packed column studies for simulated groundwater injection.
KW - Citrate
KW - DNAPL
KW - Groundwater
KW - Hydroxyl radical
KW - Iron
KW - TCE droplet
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U2 - 10.1089/ees.2008.0277
DO - 10.1089/ees.2008.0277
M3 - Article
AN - SCOPUS:63449088913
SN - 1092-8758
VL - 26
SP - 849
EP - 859
JO - Environmental Engineering Science
JF - Environmental Engineering Science
IS - 4
ER -