三维电极-电Fenton耦合法降解硝基苯废水

Degradation of Nitrobenzene Wastewater by Three-Dimension Electrode Method Coupling Electro-Fenton

采用三维电极-电Fenton耦合法处理硝基苯废水,考察了废水中有机物降解的影响因素及废水处理效果,并与三维电极法、普通电Fenton法去除硝基苯的效果进行了对比.结果表明:随电解时间的延长和初始pH值、极板间距、槽电压、Fe2+投加量、曝气量的增加,硝基苯废水中的化学需氧量(COD)和硝基苯的去除率均呈先增后降或趋于平缓的态势;最佳试验参数为电解时间2.0h、初始pH值为3.0、极板间距6 cm、槽电压30 V、Fe2+投加量1.0g/L、曝气量0.8m3/h;在此条件下,COD及硝基苯的去除率分别为93.1%和96.5%.文中还通过对中间产物进行气相色谱/质谱联用分析,探讨了硝基苯的降解机理,并进一步证明了三维电极-电Fenton耦合法较三维电极法、普通电Fenton法具有更好的硝基苯类物质去除效果.

Nitrobenzene wastewater was treated by a three-dimension electrode method coupling electro-Fenton, and the factors affecting the organic matter degradation as well as the treatment efficiency were investigated. The results were then compared with those of the three-dimension electrode method and the common electrode-Fenton method. It is found that （ 1 ） with the increase in electrolysis time, initial pH value, polar distance, cell voltage, Fe2 ＋ dosage and aeration rate, both the chemical oxygen demand （COD） and the nitrobenzene removal first increase and then decrease or change slightly; （2） the optimal conditions for the wastewater treatment are found to be： an electrolysis duration of 2.0 h, and initial pH value of 3.0, a polar distance of 6 cm, a cell voltage of 30 V, a Fe2＋ dosage of 1.0 g/L and an aeration rate of 0. 8 m3/h ; and （3） in the optimal conditions, the removals of COD and nitrobenzene reach 93.1% and 96. 5%, respectively. In addition, according to the GC-MS results of the intermediate products, the degradation mechanism of nitrobenzene is explored and the superiority of the method over the three-dimension electrode method and the common electrode-Fenton method in terms of nitrobenzene removed is validated.