Ozcan Ali, Oturan Mehmet A, Oturan Nihal, Sahin Yücel
Anadolu University, Faculty of Science, Department of Chemistry, 26470 Eskişehir, Turkey.
J Hazard Mater. 2009 Apr 30;163(2-3):1213-20. doi: 10.1016/j.jhazmat.2008.07.088. Epub 2008 Jul 26.
The removal of azo dye Acid Orange 7 (AO7) from water was investigated by the electro-Fenton technology using electrogenerated hydroxyl radicals (OH) which leads to the oxidative degradation of AO7 up to its complete mineralization. H(2)O(2) and Fe (II) ions are electrogenerated in a catalytic way at the carbon-felt cathode. AO7 decay kinetics and evolution of its oxidation intermediates were monitored by high-performance liquid chromatography. The absolute rate constant of AO7 hydroxylation reaction has been determined as (1.20+/-0.17)x10(10)M(-1)s(-1). The optimal current value for the degradation of AO7 was found as 300 mA. AO7 degradation rate was found to decrease by increase in Fe(3+) concentration beyond 0.1mM. Mineralization of AO7 aqueous solutions was followed by total organic carbon (TOC) measurements and found to be 92%. Based on TOC evolution and identification of aromatic intermediates, short-chain carboxylic acids and inorganic ions released during treatment, a plausible mineralization pathway was proposed.
采用电芬顿技术，利用电生成的羟基自由基（·OH）研究了从水中去除偶氮染料酸性橙7（AO7）的过程，该过程可导致AO7发生氧化降解直至完全矿化。在碳毡阴极上以催化方式电生成H₂O₂和Fe（II）离子。通过高效液相色谱监测AO7的衰减动力学及其氧化中间体的演变。已确定AO7羟基化反应的绝对速率常数为(1.20±0.17)×10¹⁰ M⁻¹ s⁻¹。发现AO7降解的最佳电流值为300 mA。发现当Fe(III)浓度超过0.1 mM时，AO7降解速率会降低。通过总有机碳（TOC）测量跟踪AO7水溶液的矿化情况，发现矿化率为92%。基于TOC演变以及处理过程中释放的芳香族中间体、短链羧酸和无机离子的鉴定结果，提出了一个合理的矿化途径。
