The removal of the analgesic tramadol (TMD) from water was studied by electro-Fenton (EF) process using BDD anode. Hydroxyl radicals (OH) generated in this process are very strong oxidants and able to successfully oxidize TMD until its total mineralization in aqueous solution. The oxidative degradation of TMD was very rapid with complete disappearance of 0.1 mM (26.3 mg L-1) TMD in 10 min at 500 mA constant current electrolysis. The absolute (second order) rate constant for oxidation of TMD by OH was determined using competition kinetic method and found to be (5.59 ± 0.03) ✕ 109 M-1 s-1. The quasi-complete mineralization of the 0.1 mM TMD solution was obtained in 6 h electrolysis at 500 mA current. Several oxidation reaction intermediates were identified using GC-MS analysis. Oxalic, glyoxylic and fumaric acids were identified and their evolution during electrolysis was followed along treatment. Ammonium and nitrate ions, released during the treatment, were also considered. Based on these data and TOC removal results, a possible mineralization pathway was proposed.

中文翻译：

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电芬顿镇痛曲马多的治疗：动力学，机理和能量评估。

使用BDD阳极通过电子芬顿（EF）工艺研究了从水中去除止痛曲马多（TMD）的方法。在此过程中产生的羟基自由基（OH）是非常强的氧化剂，能够成功氧化TMD，直到在水溶液中完全矿化为止。TMD的氧化降解非常迅速，在500 mA恒定电流电解下，在10分钟内0.1 mM（26.3 mg L-1）TMD完全消失。使用竞争动力学方法确定OH氧化TMD的绝对（二级）速率常数，为（5.59±0.03）✕109 M-1 s-1。在500 mA电流下电解6 h，获得了0.1 mM TMD溶液的准完全矿化作用。使用GC-MS分析鉴定了几种氧化反应中间体。草酸 鉴定了乙醛酸和富马酸，并跟踪了它们在电解过程中的演变。还考虑了在处理过程中释放的铵离子和硝酸根离子。基于这些数据和TOC去除结果，提出了可能的矿化途径。