Degradation Of Nitrobenzene By Ozone/Zeolite

The shortage and pollution of water resource is serious in China. And the removal of organic pollutant from drinking water has become a crucial problem. Among various technologies used for water purification, advanced oxidation , especially catalytic ozonation, has been received more attention due to its advantages of high efficiency and easy application.Characterization of modified zeolite and establishment of nitrobenzene detection method were carried out. Also, comparison between ozone/zeolite and ozonation alone during degradation of nitrobenzene was taken out. By investigating a series of influence effects, the results were as follows:Degradation of nitrobenzene by ozone/zeolite was more efficient in comparison to ozonation alone in simulated pollutant water. And the reaction followed pseudo-first-order kinetics. By investigating the effect of scavenger on nitrobenzene removal, it is concluded that nitrobenzene was mainly degraded by hydroxyl radicals in solution. Increasing zeolite dosage and ozone concentration also enhanced nitrobenzene removal. At the same time, nitrobenzene decomposition was independent of influent nitrobenzene concentration during ozone/zeolite. Additionally, the degradation rate of ozone/zeolite was inhibited significantly by increasing ionic strength. When the ionic strength concentration was 1×10-3mol/L, the removal of nitrobenzene by ozone/zeolite process decreased from 81.2% to 31.6% correspondingly. pH mainly affected the decomposition rate of ozone. As pH decreased from 5.5 to 3.0, the degradation rate of nitrobenzene by ozone/zeolite decreased significantly.Ozone can been adsorbed on H-form zeolite, and finally decomposed. And the process of adsorption and desorption was irreversible. However, exchanged H-form zeolite by sodium ion in equilibrium did not adsorb any ozone. After equilibrium of adsorption and desorption, the relationship of the amount of adsorbed ozone with the influent ozone concentration was linear, and the regression coefficient was 0.696. By investigating the effect of cation and zeolite type on ozone/zeolite oxiding nitrobenzene, it was found that the nitrobenzene removal rate was significantly inhibited by calcium ion. It was verified that...