Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/45244
標題: pH dependence of persulfate activation by EDTA/Fe(III) for degradation of trichloroethylene
作者: Liang, C.J.
梁振儒
Liang, C.P.
Chen, C.C.
關鍵字: Sulfate radical
Groundwater
Remediation
In situ chemical oxidation
in-situ remediation
hydrogen-peroxide
aqueous-solution
ferrous ion
oxidation
tce
peroxydisulfate
complexes
radicals
acid
期刊/報告no:: Journal of Contaminant Hydrology, Volume 106, Issue 3-4, Page(s) 173-182.
摘要: The ability of free ferrous ion activated persulfate (S(2)O(8)(2-)) to generate sulfate radicals (SO(4)(-)) for the oxidation of trichloroethylene (TCE) is limited by the scavenging of SO(4)(-) with excess Fe(2+) and a quick conversion of Fe(2+) to Fe(3+). This study investigated the applicability of ethylene-diamine-tetra-acetic acid (EDTA) chelated Fe(3+) in activating persulfate for the destruction of TCE in aqueous phase under pH 3, 7 and 10. Fe(3+) and EDTA alone did not appreciably degrade persulfate. The presence of WE in the EDTA/Fe(3+) activated persulfate system can induce faster persulfate and EDTA degradation due to iron recycling to activate persulfate under a higher pH condition. Increasing the pH leads to increases in pseudo-first-order-rate constants for TCE, S(2)O(8)(2-) and EDTA degradations, and Cl generation. Accordingly, the experiments at pH 10 with different EDTA/Fe(3+) molar ratios indicated that a 1/1 ratio resulted in a remarkably higher degradation rate at the early stage of reaction as compared to results by other ratios. Higher persulfate dosage under the EDTA/Fe(3+) molar ratio of 1/1 resulted in greater TCE degradation rates. However, increases in persulfate concentration may also lead to an increase in the rate of persulfate consumption. (C) 2009 Elsevier B.V. All rights reserved.
URI: http://hdl.handle.net/11455/45244
ISSN: 0169-7722
文章連結: http://dx.doi.org/10.1016/j.jconhyd.2009.02.008
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