UMTP and Department of Chemistry, University of Beira Interior, 6201-001 Covilhã, Portugal.
J Hazard Mater. 2011 Feb 28;186(2-3):1033-41. doi: 10.1016/j.jhazmat.2010.11.108. Epub 2010 Dec 3.
The electrochemical oxidation of four aromatic amines, with different substituent groups, 3-amino-4-hydroxy-5-nitrobenzenesulfonic acid (A1), 5-amino-2-methoxybenzenesulfonic acid (A2), 2,4-dihydroxyaniline hydrochloride (A3) and benzene-1,4-diamine (A4), was performed using as anode a boron-doped diamond electrode, commercially available at Adamant Technologies. Tests were run at room temperature with model solutions of the different amines, with concentrations of 200 ppm, using as electrolyte 0.035 M Na(2)SO(4) aqueous solutions, in a batch cell with recirculation, at different current densities (200 and 300 A m(-2)). The following analyses were performed with the samples collected during the assays: UV-Vis spectrophotometry, chemical oxygen demand (COD), total organic carbon (TOC), total Kjeldahl nitrogen, ammonia nitrogen, nitrates and HPLC. Results have shown a good electrodegradation of all the amines tested, with COD removals, after 6 h assays, higher than 90% and TOC removals between 60 and 80%. Combustion efficiency (η(C)), which measures the tendency to convert organic carbon to CO(2), was also determined for all the amines, being η(CA1)<η(CA2)<η(CA3)<η(CA4)=0.99.
采用市售的掺硼金刚石电极作为阳极，对四种具有不同取代基的芳香胺，即 3-氨基-4-羟基-5-硝基苯磺酸（A1）、5-氨基-2-甲氧基苯磺酸（A2）、2,4-二羟苯胺盐酸盐（A3）和苯-1,4-二胺（A4）进行电化学氧化。在室温下，使用模型溶液进行测试，胺的浓度为 200ppm，电解质为 0.035M 的硫酸钠水溶液，在带有循环的分批槽中，在不同的电流密度（200 和 300A m(-2))下进行。对在实验过程中收集的样品进行以下分析：紫外可见分光光度法、化学需氧量（COD）、总有机碳（TOC）、总凯氏氮、氨氮、硝酸盐和高效液相色谱法。结果表明，所有测试的胺都得到了很好的电极降解，在 6 小时的测试后，COD 去除率高于 90%，TOC 去除率在 60%至 80%之间。还确定了所有胺的燃烧效率（η(C)），它衡量将有机碳转化为 CO(2)的趋势，结果为 η(CA1)<η(CA2)<η(CA3)<η(CA4)=0.99。
