Experiments On Nitrobenzene By Cavitating Water Jets With Fenton

Nitrobenzene contamination is a sort of representive organic pollutants which are difficult to be degraded. The numerous amount of nitrobenzene contamination is doing great harm to the environment and can be widely found in industrial waster water. So it must be discharged with an adequate treatment. The disposal methods of nitrobenzene waster water include physical method, chemical method and biological method. However, these methods can't degrade nitrobenzene adequately. Yet the cavitating water jet can provide extreme condition, high temperature (5000K) and high pressure (1.013×108Pa), which can degrade the complicated organic pollutant. The scholars have applied it to the degrading of PCP, benzene and toluene, but there's no report of degrading the nitrobenzene.The thesis applies cavitating water jet to degrading nitrobenzene waste water which is prepared in the lab, and then studies the process conditions for degradation techniques of the cavitating water jet only and the technology of Fenton oxidative degradation, combining with cavitating water jets. The results of these two techniques are analyzed and compared. What's more, the by-products of the technology of Fenton oxidative degradation combined with cavitating water jets on nitrobenzene are analyzed with HPLC, and thus the mechanism of reaction is confirmed. The main contents are as follows:①The best action condition to degrade the polluted water that includes nitrobenzene by cavitating water jet only is that pH reaches 3.0, initial nitrobenzene concentration hits 50mg/L, confining pressure hits 0.5MPa, reaction time touches 30 minutes and pumping pressure reaches 10Mpa. The degrading rate is most significant, reaching 31.89%. However, for the techniques of cavitating water jet combining Fenton, the degrading rate is 95.06%.Meanwhile, the best action condition is that Fe2+ concentration reaches 40mg/L, Fenton concentration touches 150mg/L, confining pressure hits 0.5MPa, pH reaches 3.0 and pumping pressure hits 10Mpa. So the techniques of cavitating water jet combining Fenton can degrade the nitrobenzene effectively.②Through examing the influence of dosage of HO·radical scavenger on degradation effect of nitrobenzene and the analysis of HPLC, it can be concluded that the mechanism of cavitating degradation of nitrobenzene is oxidizing of HO·. And then the mechanism of reaction of the technology of Fenton degradation combining cavitating water jets on nitrobenzene has been confirmed. Cavitating Water Jets can make Fenton release more HO·as well as enhance the catalytic capacity of Fe2+, so as to directly degrade or oxidative nitrobenzene, which turns into some small organic molecules such as chain hydrocarbon and organic acids etc.③Synergetic effect of cavitation and nitrobenzenephthalein has appeared in the technology of nitrobenzenephthalein oxidative degradation combining cavitating water jets on nitrobenzene. The promoted factor for nitrobenzene degradation rate constant to be at about 2.37.