title: Study of degradation intermediates formed during electrochemical oxidation of pesticide residue 2,6-dichlorobenzamide (BAM) in chloride medium at boron doped diamond (BDD) and platinum anodes.
abstract: For electrochemical oxidation to become applicable in water treatment outside of laboratories, a number of challenges must be elucidated. One is the formation and fate of degradation intermediates of targeted organics. In this study the degradation of the pesticide residue 2,6-dichlorobenzamide, an important groundwater pollutant, was investigated in a chloride rich solution with the purpose of studying the effect of active chlorine on the degradation pathway. To study the relative importance of the anodic oxidation and active chlorine oxidation in the bulk solution, a non-active BDD and an active Pt anode were compared. Also, the effect of the active chlorine oxidation on the total amount of degradation intermediates was investigated. We found that for 2,6-dichlorobenzamide, active chlorine oxidation was determining for the initial step of the degradation, and therefore yielded a completely different set of degradation intermediates compared to an inert electrolyte. For the Pt anode, the further degradation of the intermediates was also largely dependent on active chlorine oxidation, while for the BDD anode anodic oxidation was most important. It was also found that the presence of active chlorine led to fewer degradation intermediates compared to treatment in an inert electrolyte.
authors.affiliation: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Niels Bohrs Vej 8, 6700 Esbjerg, Denmark. Electronic address: htm@bio.aau.dk.
authors.forename: Henrik Tækker
authors.initials: HT
authors.lastname: Madsen
authors.affiliation: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Niels Bohrs Vej 8, 6700 Esbjerg, Denmark.
authors.forename: Erik Gydesen
authors.initials: EG
authors.lastname: Søgaard
authors.affiliation: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Niels Bohrs Vej 8, 6700 Esbjerg, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Muff
mesh_terms: D001549:Benzamides / Q000737:chemistry*; D001895:Boron / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D018130:Diamond / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010573:Pesticide Residues / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D001549:Benzamides; D002712:Chlorides; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D010984:Platinum; D018130:Diamond; C057454:2,6-dichlorobenzamide; D001895:Boron; D010100:Oxygen
keywords: 2,6-Dichlorobenzamide; Chloride medium; Degradation intermediates; Electrochemical oxidation; Pesticide pollution