Mn_3O_4催化臭氧化处理钻井废水

Treatment of drilling wastewater by Mn_3O_4 catalytic ozonation

采用锰系氧化物对钻井废水进行催化臭氧化处理,考察了不同初始pH、催化剂投加量以及臭氧投加量等因素对COD去除率的影响,探讨了Mn3O4表面电荷情况、化学吸附特性及催化臭氧产生·OH机理。结果表明,在初始pH为12,催化剂投加量为5g/L,臭氧投加量为18 mg/min,反应时间为20 min时,Mn3O4较Mn O2和单独臭氧氧化去除COD的效果更明显;Mn3O4的表面带负电荷,发生了水合羟基化过程,且Mn3O4与钻井废水中的污染物产生了化学吸附;臭氧与锰原子形成σπ-键合吸附于Mn3O4表面,经π*轨道能级的下降而进入活化状态,最终导致吸附于Mn3O4表面的OH-与臭氧相互作用产生·OH。

Treatment of drilling wastewater by catalytic ozonation with manganese oxi-des was investigated,the effects of initial pH,catalyst dosage,ozone dosage,etc.on COD removal efficacy were examined,and the Mn3O4 surface charge,chemical adsorption characteristics,mechanism of generating hydroxyl radicals（· OH）were also explored.The results indicated that under the optimal conditions of initial pH 12,catalyst dosage of 5 g /L,ozone dosage of 18 mg/min and reaction time of 20 min,compared with Mn O2 and ozonation,Mn3O4 was shown to perform best for COD degradation.The surface of Mn3O4 was negative charged,which led to the process of hydroxylation,furthermore,chemical absorption also happened due to the reaction between Mn3O4 and drilling wastewater pollutants.Ozoneand manganese atoms formed σπ-bond adsorbed on the su-rface of Mn3O4,by π＊ orbital dropping into the activated state,while the OH-adsorbed on the surface of Mn3O4,which eventually interacted with ozone to generate ·OH.