Abstract The removal of the phenylurea herbicide monolinuron (MLN) from water was investigated by the electro-Fenton method, based on the electro-catalytic in situ continuous production of large amounts of the strong oxidant hydroxyl radicals. The effect of several parameters, including the Fe2+ initial concentration, applied current and type of anode (Pt and boron-doped diamond - BDD), on the MLN degradation kinetics was evaluated. MLN decay kinetics was monitored by HPLC, fitting a pseudo first-order reaction, leading to a rate constant kabs = (3.1 ± 0.2) × 109 M−1 s−1. Several oxidation intermediates species were identified and followed by HPLC and GC–MS. A quasi complete mineralization rate (98% TOC removal) of MLN solution was reached after 8 h of treatment on BDD anode with low energy consumption. Identification of carboxylic acids and inorganic ions was carried out by HPLC and ionic chromatography analyses. Based on identification of aromatic and aliphatic intermediates, inorganic end-products and TOC removal value, a complete MLN mineralization pathway was also proposed.

中文翻译：

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电芬顿处理去除水中除草剂单酰脲

摘要 基于电催化原位连续产生大量强氧化剂羟基自由基，采用电芬顿法对水中苯脲类除草剂单酰脲(MLN)的去除进行了研究。评估了几个参数对 MLN 降解动力学的影响，包括 Fe2+ 初始浓度、施加的电流和阳极类型（Pt 和掺硼金刚石 - BDD）。MLN 衰减动力学由 HPLC 监测，拟合伪一级反应，导致速率常数 kabs = (3.1 ± 0.2) × 109 M-1 s-1。鉴定了几种氧化中间体，然后进行了 HPLC 和 GC-MS。在低能耗的 BDD 阳极上处理 8 小时后，MLN 溶液达到准完全矿化率（98% TOC 去除）。羧酸和无机离子的鉴定通过 HPLC 和离子色谱分析进行。基于对芳香族和脂肪族中间体、无机终产物和TOC去除值的鉴定，还提出了完整的MLN成矿途径。