title: Electrogeneration of H(2) for Pd-catalytic hydrodechlorination of 2,4-dichlorophenol in groundwater.
abstract: A novel electrolytic groundwater remediation process, which used the H(2) continuously generated at cathode to achieve in situ catalytic hydrodechlorination, was developed for the treatment of 2,4-dichlorophenol (2,4-DCP) in groundwater. Catalytic hydrodechlorination using Pd supported on bamboo charcoal and external H(2) showed that 2,4-DCP was completely dechlorinated to phenol within 30 min at pH ≤ 5.5. In a divided electrolytic system, the catalytic hydrodechlorination of 2,4-DCP in cathodic compartment by H(2) generated at the cathode under 20 and 50 mA reached 100% at 120 and 60 min, respectively. Two column experiments with influent pHs of 5.5 (unconditioned) and 2 were conducted to evaluate the feasibility of this process. The 2,4-DCP removal efficiencies were about 63% and nearly 100% at influent pHs of 5.5 and 2, respectively. Phenol was solely produced by 2,4-DCP hydrodechlorination, and was subsequently degraded at the anode. A low pH could enhance the hydrodechlorination, but was not necessarily required. This study provides the preliminary results of a novel effective electrolytic process for the remediation of groundwater contaminated by chlorinated aromatics.
authors.affiliation: State Key Lab of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Zheng
authors.forename: Jianguo
authors.initials: J
authors.lastname: Bao
authors.forename: Peng
authors.initials: P
authors.lastname: Liao
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Songhu
authors.initials: S
authors.lastname: Yuan
authors.forename: Man
authors.initials: M
authors.lastname: Tong
authors.forename: Huayun
authors.initials: H
authors.lastname: Long
mesh_terms: D002606:Charcoal / Q000737:chemistry; D002733:Chlorophenols / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004566:Electrodes; D004572:Electrolysis / Q000379:methods*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006108:Graphite / Q000737:chemistry; D060587:Groundwater / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010165:Palladium / Q000737:chemistry; D006109:Poaceae / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D002733:Chlorophenols; D014874:Water Pollutants, Chemical; D002606:Charcoal; D010165:Palladium; D006108:Graphite; D006859:Hydrogen; C004762:2,4-dichlorophenol