Effect of SO on 1,1,1-Trichloroethane Degradation by Fe0 in Aqueous Solution
Article first published online: 20 JUN 2012
© 2012, The Author(s). Groundwater © 2012, National Ground Water Association
Volume 51, Issue 2, pages 286–292, March/April 2013
How to Cite
Yu, J., Liu, W., Zeng, A., Guan, B. and Xu, X. (2013), Effect of SO on 1,1,1-Trichloroethane Degradation by Fe0 in Aqueous Solution. Groundwater, 51: 286–292. doi: 10.1111/j.1745-6584.2012.00957.x
- Issue published online: 6 MAR 2013
- Article first published online: 20 JUN 2012
- Received June 2011, accepted May 2012.
Sulfate in groundwater has been previously shown to change the reactivity of Fe0 in permeable reactive barriers for reducing chlorinated organics. To better understand the effect and mechanism of SO, the degradation of 1,1,1-trichloroethane (TCA) by Fe0 in unbuffered aqueous solutions with and without SO was investigated. In a Fe0-TCA-H2O system with initial pH of 2.0 to 10.0, the maximum removal rate of TCA was achieved at the initial pH 6.0 with pseudo-first-order constant Kobs 9.0 × 10−3/min. But in a Fe0-TCA-Na2SO4-H2O system, the removal rate of TCA decreased remarkably with a reduction in Kobs to 1.0 × 10−3/min, and the pH varied from 6.0 to 9.6, indicating an inhibition of TCA dehydrochlorination by SO. Sulfate remarkably inhibited TCA degradation via changing the route of Fe0 dissolution. It accelerated the dissolution of Fe0 and transformed the intermediate form Fe(OH)ads to Fe2(SO4)ads, which weakened the affinity between Fe and TCA, and thus depressed the degradation of TCA by Fe0.