[Mechanism of degradation of nitrobenzene by ozone/zeolite process].
Adsorption and desorption of ozone on H-form zeolite was investigated in solution. The results showed that ozone could be adsorbed on H-form zeolite, and finally decomposed. And the process of adsorption and desorption was irreversible. After equilibrium of adsorption and desorption, the relationship of the amount of adsorbed ozone with the influent ozone concentration was linear. However, exchanged H-form zeolite by sodium ion at the concentration of 1 x 10(-3) mol/L did not adsorb any ozone. By investigating the effect of cation and zeolite type on ozone/zeolite process oxidizing nitrobenzene, it was investigated that the nitrobenzene removal rate was significantly inhibited by calcium ion. Additionally, during the ozonation of nitrobenzene by ozone/Na-form zeolite and ozone/NH4-form zeolite process individually, the removal rate of nitrobenzene by ozone/Na-form zeolite process was gradually improved as the sodium ion dissolved in solution. It was verified that cations affected ozone diffusing into the pore of zeolite and then self-decomposition and catalysis decomposition. After dealuminated, the ozone/H-form zeolite process did not show any efficiency on nitrobenzene removal. In the end, ozone also can be adsorbed and decomposed at pH 3.0 in zeolite, which showed that the effect of hydrogen ion was not as well as other cations.
Qin
Qing-dong
QD
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. qinqingdong@yahoo.com.cn
Liu
Ke
K
Ma
Jun
J
Yang
Yi-xin
YX
D009578:Nitrobenzenes / Q000737:chemistry* / Q000302:isolation & purification; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*; D017641:Zeolites / Q000737:chemistry*
D009578:Nitrobenzenes; D014874:Water Pollutants, Chemical; D017641:Zeolites; D010126:Ozone; C036077:nitrobenzene