Louhichi B, Ahmadi M F, Bensalah N, Gadri A, Rodrigo M A
Ecole Nationale d'Ingénieurs de Gabès, Zrig 6072, Tunisia.
J Hazard Mater. 2008 Oct 30;158(2-3):430-7. doi: 10.1016/j.jhazmat.2008.01.093. Epub 2008 Feb 7.
In this work, the electrochemical oxidation on boron-doped diamond of synthetic wastes polluted with surfactant sodium dodecylbenzenesulfonate (SDBS) has been studied. Results show that SDBS can be successfully removed with this technology inside different current densities and concentration ranges. The oxidation of the SDBS seems to occur in two main sequential steps: the first is the rapid degradation of SDBS, and the final is the less efficient oxidation of aliphatic intermediates to carbon dioxide. The nature of supporting electrolyte (NaCl, Na(2)SO(4) and K(3)PO(4)) influences on the efficiency of the electrochemical oxidation process. The treatment of the NaCl solution seems to be more efficient in the chemical oxygen demand (COD) removal, while the sulphate and specially the phosphate media improve the TOC removal. However, in spite of this observation, chemical oxidation of SDBS by different types of oxidants cannot explain alone the results of the electrochemical oxidation with diamond anodes. This suggests that the synergistic effect of the different oxidation mechanisms that occurs into the electrochemical cell (direct oxidation and mediated oxidation by hydroxyl radicals and by oxidants formed from the electrolyte) is the responsible of the great efficiencies obtained with this technology in the treatment of organics.
在这项工作中，研究了在掺硼金刚石上对被表面活性剂十二烷基苯磺酸钠（SDBS）污染的合成废料进行电化学氧化的情况。结果表明，利用该技术在不同电流密度和浓度范围内能够成功去除SDBS。SDBS的氧化似乎主要分两个连续步骤进行：第一步是SDBS的快速降解，最后一步是脂肪族中间体氧化为二氧化碳的效率较低的过程。支持电解质（NaCl、Na₂SO₄和K₃PO₄）的性质会影响电化学氧化过程的效率。NaCl溶液的处理在化学需氧量（COD）去除方面似乎更有效，而硫酸盐特别是磷酸盐介质能提高总有机碳（TOC）的去除率。然而，尽管有此观察结果，但不同类型氧化剂对SDBS的化学氧化无法单独解释金刚石阳极电化学氧化的结果。这表明在电化学电池中发生的不同氧化机制（直接氧化以及由羟基自由基和由电解质形成的氧化剂介导的氧化）的协同效应是该技术在处理有机物时获得高效的原因。
