Degradation of Wastewater Containing Nitrobenzene by High Gravity-Ultrasonic/Ozonation/Electrolysis Technology

The integrated high gravity-ultrasonic/ozonation/electrolysis technology was applied in the pretreatment of wastewater containing nitrobenzene.The effect of pH value,high gravity factor,liquid flow-rate and electric current density on removal of COD and nitrobenzene compounds was investigated.Experimental results have determined the optimal process regime involving a high gravity factor of 100,an electric current density of 20mA/cm2,a liquid flow-rate of 100L/h,and an initial liquid pH value of 11.After the wastewater had been treated for 180 min,the degradation of nitrobenzene and COD reached 99% and 80%,respectively,with the biochemical coefficient(BOD/COD) equating to 0.64,and the subsequent treatment of wastewater could be carried out by conventional biochemical means.Compared with traditional aerationozone contactors,a rotating packed bed with high mass transfer characteristics could be used to increase the ozonation treatment efficiency.