LSRE-Laboratory of Separation and Reaction Engineering-Associate Laboratory LSRE/LCM, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
Water Res. 2012 Oct 1;46(15):4599-613. doi: 10.1016/j.watres.2012.06.038. Epub 2012 Jul 3.
This work proposes an efficient combined treatment for the decontamination of a pesticide-containing wastewater resulting from phytopharmaceutical plastic containers washing, presenting a moderate organic load (COD=1662-1960 mg O₂ L⁻¹; DOC=513-696 mg C L⁻¹), with a high biodegradable organic carbon fraction (81%; BOD₅=1350-1600 mg O₂ L⁻¹) and a remaining recalcitrant organic carbon mainly due to pesticides. Nineteen pesticides were quantified by LC-MS/MS at concentrations between 0.02 and 45 mg L⁻¹ (14-19% of DOC). The decontamination strategy involved a sequential three-step treatment: (a) biological oxidation process, leading to almost complete removal of the biodegradable organic carbon fraction; (b) solar photo-Fenton process using CPCs, enhancing the bio-treated wastewater biodegradability, mainly due to pesticides degradation into low-molecular-weight carboxylate anions; (c) and a final polishing step to remove the residual biodegradable organic carbon, using a biological oxidation process. Treatment performance was evaluated in terms of mineralization degree (DOC), pesticides content (LC-MS/MS), inorganic ions and low-molecular-weight carboxylate anions (IC) concentrations. The estimated phototreatment energy necessary to reach a biodegradable wastewater, considering pesticides and low-molecular-weight carboxylate anions concentrations, Zahn-Wellens test and BOD₅/COD ratio, was only 2.3 kJ(UV) L⁻¹ (45 min of photo-Fenton at a constant solar UV power of 30 W m⁻²), consuming 16 mM of H₂O₂, which pointed to 52% mineralization and an abatement higher than 86% for 18 pesticides. The biological oxidation/solar photo-Fenton/biological oxidation treatment system achieved pesticide removals below the respective detection limits and 79% mineralization, leading to a COD value lower than 150 mg O₂ L⁻¹, which is in agreement with Portuguese discharge limits regarding water bodies.
本工作提出了一种有效的联合处理方法，用于净化植物制药塑料容器清洗产生的含有农药的废水，该废水具有中等有机负荷（COD=1662-1960mgO₂L⁻¹；DOC=513-696mgCL⁻¹），其中高比例的有机碳可生物降解（81%；BOD₅=1350-1600mgO₂L⁻¹），其余的难生物降解有机碳主要来自农药。采用 LC-MS/MS 方法测定了 19 种农药的浓度，介于 0.02 和 45mgL⁻¹之间（DOC 的 14-19%）。该净化策略包括顺序进行的三个处理步骤：（a）生物氧化过程，几乎完全去除可生物降解的有机碳部分；（b）使用 CPCs 的太阳能光芬顿工艺，提高经生物处理的废水的可生物降解性，主要是由于农药降解为低分子量的羧酸根阴离子；（c）最后使用生物氧化工艺去除剩余的可生物降解有机碳。根据矿化度（DOC）、农药含量（LC-MS/MS）、无机离子和低分子量羧酸根阴离子（IC）浓度评估处理性能。考虑到农药和低分子量羧酸根阴离子的浓度、Zahn-Wellens 测试和 BOD₅/COD 比值，达到可生物降解废水所需的估计光处理能量仅为 2.3kJ(UV)L⁻¹（45 分钟的光芬顿反应，在恒定的 30Wm⁻²太阳紫外光功率下），消耗 16mM 的 H₂O₂，这表明有 52%的矿化度和 86%以上的 18 种农药的去除率。生物氧化/太阳能光芬顿/生物氧化处理系统实现了低于各自检测限的农药去除率和 79%的矿化度，使 COD 值低于 150mgO₂L⁻¹，符合葡萄牙关于水体的排放标准。
