Decolorization and mineralization of Orange G azo dye solutions by anodic oxidation with a boron-doped diamond anode in divided and undivided tank reactors
Decolorization and mineralization of Orange G azo dye solutions by anodic oxidation with a boron-doped diamond anode in divided and undivided tank reactors
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DOI：
10.1016/j.electacta.2014.03.066
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发表时间：
2014-06-01
影响因子：
6.6
通讯作者：
Brillas, Enric
中科院分区：
文献类型：
--
作者：
El-Ghenymy, Abdellatif;Centellas, Francesc;Brillas, Enric
以含硼金刚石(BDD)为阳极，不锈钢为阴极，在pH 3.0、电流密度为33.3~150 mA cm(-2)的条件下，研究了100 cm(-3)0.52-6.34 mmoldm(-3)橙黄G偶氮染料溶液的阳极氧化和矿化过程。在这两个体系中，有机物都被BDD阳极上水氧化产生的羟基自由基破坏。含有0.52 mmoldm(-3)染料的溶液在两个电池中都能完全脱色，在较大的电流密度下脱色速度更快。分裂细胞的脱色速度总是快于未分裂细胞。在分隔槽反应器中，在电流密度>=66.7 mA cm(-2)下运行不到330分钟即可实现全部矿化，而在未分隔槽中，对于150 mA cm(-2)，这有时是可行的，只要420分钟。当橙色G含量达到6.34 mmoldm(-3)时，100 Ma cm(-2)处的总矿化也更容易在分裂的细胞中实现。电流密度越低，染料含量越高，矿化电流效率越高。染料的衰减遵循准一级动力学，其表观速率常数随电流密度的增大而增大。橙色G的完全脱色和消失所需的电解时间相似，表明芳香族副产物被迅速破坏，不会在介质中积累。在橙色G矿化过程中，最终生成马来酸、酒石酸、醋酸、甲酸、草酸和草酸等羧酸，而铵离子和硫酸盐是主要的无机离子。(C)2014爱思唯尔有限公司。保留所有权利。
The decolorization and mineralization of 100 cm(3) of 0.52-6.34 mmol dm(-3) Orange G azo dye solutions at pH 3.0 and current density between 33.3 and 150 mA cm(-2) have been studied by anodic oxidation (AO) using a divided or undivided tank reactor with a boron-doped diamond (BDD) anode and a stainless steel cathode. In both systems, organics were destroyed by hydroxyl radicals generated at the BDD anode from water oxidation. Solutions with 0.52 mmol dm(-3) of the dye were completely decolorized in both cells, more rapidly at greater current density. The divided cell always gave faster decolorization than the undivided one. Overall mineralization in the divided tank reactor was attained in less than 330 min operating at current densities >= 66.7 mA cm(-2), whereas in the undivided cell, this was feasible at times as long as 420 min for 150 mA cm(-2). For Orange G contents up to 6.34 mmol dm(-3), total mineralization at 100 mA cm(-2) was also more easily reached in the divided cell. The mineralization current efficiency always rose at lower current density and higher dye content. The dye decayed obeying a pseudo-first-order kinetics and its apparent rate constant increased at higher current density. A similar electrolysis time was required for total decolorization and disappearance of Orange G, indicating that aromatic by-products were rapidly destroyed and did not accumulate in the medium. Final carboxylic acids like maleic, tartronic, acetic, formic, oxalic and oxamic were generated, whereas ammonium and sulfate were the main inorganic ions released during Orange G mineralization. (C) 2014 Elsevier Ltd. All rights reserved.