Electrochemical reduction and oxidation of DDT

Abstract

Electrolysis has been studied as a possible method to treat DDT wastes. In methanol, the major process was dehydrochlorination to DDE followed by further reduction. In an aqueous emulsion containing 1% heptane and 0.1% Triton SP-175®, DDT was reduced at a deposited lead electrode with sodium sulphate as the supporting electrolyte by sequential hydrodechlorination of the aliphatic chlorine atoms. An excellent material balance was achieved, but the current efficiency was poor, even at low current densities. Electrooxidation of DDT was also investigated; in aqueous solutions or emulsion, little oxidation occurred because of competing oxidation of water at the highly positive potentials needed to oxidize DDT. In acetonitrile, electrooxidation occurred with high current efficiency by way of "electrochemical combustion" of DDT and its intermediate oxidation products to CO2. We conclude that development of an electrolytic technology for destroying DDT wastes is unlikely.Key words: electroreduction, electrooxidation, voltammetry, surfactant media.

Electrochemically Assisted Remediation of Pesticides in Soils and Water: A Review

“…This concentration effect was noticed some time ago in a study stating that the more significant application of electrochemical technology should not be anodic oxidation but the cathodic dechlorination of chlorinated pesticides. 165 Although this cathodic process is not a final treatment, a very significant decrease in the toxicity of chlorinated pesticides is obtained, and the cathodic process may be a good alternative when combined with cheaper treatments. 166,167 A final application of electrolytic systems is to modify the adsorption capacity 168 of an adsorbent or ion exchange processes 169 of a resine using electrochemically assisted processes.…”

Electroreductive Remediation of Halogenated Environmental Pollutants

“…Figure depicts structures of DDT and its various degradation products. Electrochemical research has involved the reduction of DDT at different electrodes and in various solvents. − Depending on the choice of conditions, both partial and complete dechlorinations of DDT can be achieved to afford products such as DDD, 4,4′-(2,2-dichloro­ethene-1,1-diyl)­bis­(chlorobenzene) (DDE), 4,4′-(2-chloro­ethene-1,1-diyl)­bis­(chlorobenzene) (DDMU), and 4,4′-(ethene-1,1-diyl)­bis­(chlorobenzene) (DDNU). Moreover, the electrodegradation of DDT in an ionic liquid was examined …”

Electrochemical Dehalogenation of Organic Pollutants

“…Shown in Figure 3 are the structures of DDT and its degradation products. Subsequent investigations involved the reduction of DDT in a variety of solvent systems and at a variety of electrodes (including mercury, lead, nickel, and graphite felt) [52][53][54][55][56]; this work demonstrated that, depending on the choice of experimental conditions, different degrees of dechlorination could be achieved to produce DDD, DDE, DDMU, and DDNU [52][53][54][55][56]. In addition, ionic liquids have been employed as media for the electrochemical degradation of DDT [57].…”