TY - JOUR
T1 - A three-electrode column for Pd-catalytic oxidation of TCE in groundwater with automatic pH-regulation and resistance to reduced sulfur compound foiling
AU - Yuan, Songhu
AU - Chen, Mingjie
AU - Mao, Xuhui
AU - Alshawabkeh, Akram N.
N1 - Funding Information:
This work was supported by the US National Institute of Environmental Health Sciences (NIEHS, Grant No. P42ES017198 ), the Natural Science Foundation of China (NSFC, No. 41172220 ), and the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (No. CUGL110608). We appreciate the assistance in ESR assay by Prof. David Budil and Mr. Xianzhe Wang in Department of Chemistry & Chemical Biology, Northeastern University. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIEHS, the National Institutes of Health or Lawrence Livermore National Security, LLC.
PY - 2013/1/1
Y1 - 2013/1/1
N2 - A hybrid electrolysis and Pd-catalytic oxidation process is evaluated for degradation of trichloroethylene (TCE) in groundwater. A three-electrode, one anode and two cathodes, column is employed to automatically develop a low pH condition in the Pd vicinity and a neutral effluent. Simulated groundwater containing up to 5 mM bicarbonate can be acidified to below pH 4 in the Pd vicinity using a total of 60 mA with 20 mA passing through the third electrode. By packing 2 g of Pd/Al2O3 pellets in the developed acidic region, the column efficiency for TCE oxidation in simulated groundwater (5.3 mg/L TCE) increases from 44 to 59 and 68% with increasing Fe(II) concentration from 0 to 5 and 10 mg/L, respectively. Different from Pd-catalytic hydrodechlorination under reducing conditions, this hybrid electrolysis and Pd-catalytic oxidation process is advantageous in controlling the fouling caused by reduced sulfur compounds (RSCs) because the in situ generated reactive oxidizing species, i.e., O2, H2O2 and OH, can oxidize RSCs to some extent. In particular, sulfite at concentrations less than 1 mM even greatly increases TCE oxidation by the production of SO4•-, a strong oxidizing radical, and more OH.
AB - A hybrid electrolysis and Pd-catalytic oxidation process is evaluated for degradation of trichloroethylene (TCE) in groundwater. A three-electrode, one anode and two cathodes, column is employed to automatically develop a low pH condition in the Pd vicinity and a neutral effluent. Simulated groundwater containing up to 5 mM bicarbonate can be acidified to below pH 4 in the Pd vicinity using a total of 60 mA with 20 mA passing through the third electrode. By packing 2 g of Pd/Al2O3 pellets in the developed acidic region, the column efficiency for TCE oxidation in simulated groundwater (5.3 mg/L TCE) increases from 44 to 59 and 68% with increasing Fe(II) concentration from 0 to 5 and 10 mg/L, respectively. Different from Pd-catalytic hydrodechlorination under reducing conditions, this hybrid electrolysis and Pd-catalytic oxidation process is advantageous in controlling the fouling caused by reduced sulfur compounds (RSCs) because the in situ generated reactive oxidizing species, i.e., O2, H2O2 and OH, can oxidize RSCs to some extent. In particular, sulfite at concentrations less than 1 mM even greatly increases TCE oxidation by the production of SO4•-, a strong oxidizing radical, and more OH.
KW - Electrolytic
KW - Groundwater remediation
KW - Pd
KW - Reduced sulfur compounds
KW - TCE
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U2 - 10.1016/j.watres.2012.10.009
DO - 10.1016/j.watres.2012.10.009
M3 - Article
C2 - 23121896
AN - SCOPUS:84870065694
SN - 0043-1354
VL - 47
SP - 269
EP - 278
JO - Water Research
JF - Water Research
IS - 1
ER -