Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment
Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment
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DOI：
10.1016/j.jhazmat.2014.10.003
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发表时间：
2015-02-11
影响因子：
13.6
通讯作者：
Radjenovic, Jelena
中科院分区：
文献类型：
--
作者：
Garcia-Segura, Sergi;Keller, Juerg;Radjenovic, Jelena
电化学高级氧化工艺(EAOPs)作为去除水中痕量有机污染物的一种很有前途的技术已被广泛研究，但很少被用于实际废水的处理。采用含硼金刚石(BDD)阳极阳极氧化处理含29种目标药物和农药的城市污水处理厂二级出水。从污染物的衰减、溶解有机碳和化学需氧量的去除来评估处理的效果。考察了外加电流和pH对处理效果的影响。主要由于BDD表面形成的羟基自由基的作用，这种EAOP可以获得几乎完全的出水有机物和微量污染物的矿化。废水中的氯离子在BDD阳极处被氧化生成活性氯物种(Cl2/HClO/ClO-)，它们是竞争性氧化剂，产生氯胺和有机卤素副产物，定量为可吸附的有机卤素。然而，HClO/ClO-物种的进一步阳极氧化导致了ClO_3~-和ClO_4~-离子的产生。这些物种的形成阻碍了作为单级三级处理的应用，但后阴极还原氯酸盐和高氯酸盐物种可能会降低与它们在环境中存在相关的风险。(C)2014爱思唯尔B.V.保留所有权利。
Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl- ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl-2/HClO/ClO-), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO- species led to the production of ClO3- and ClO4- ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment. (C) 2014 Elsevier B.V. All rights reserved.