Abstract:

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, Fe ^{2 ＋} 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 Fe ^2＋ 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.

Key words: wastewater treatment, three-dimension electrode, electro-Fenton, nitrobenzene