摘要
Fe_(3)O_(4)-CoO/Al_(2)O_(3)catalyst was prepared by incipient wetness impregnation using Fe(NO3)3.9H2O and Co(NO3)2.6H2O as the precursors,and its catalytic performance was investigated in ozonation of 2-(2,4-dichlorophenoxy)propionic acid(2,4-DP),nitrobenzene and oxalic acid.The experimental results indicated that Fe_(3)O_(4)-CoO/Al_(2)O_(3)catalyst enabled an interesting improvement of ozonation efficiency during the degradation of each organic pollutant,and the Fe_(3)O_(4)-CoO/Al_(2)O_(3)catalytic ozonation system followed a radical-type mechanism.The kinetics of ozonation alone and Fe_(3)O_(4)-CoO/Al_(2)O_(3)catalytic ozonation of three organic pollutants in aqueous solution were discussed under the mere consideration of direct ozone reaction and OH radical reaction to well investigate its performance.In the catalytic ozonation of 2,4-DP,the apparent reaction rate constants(k)were determined to be 1.456×10^-2 min-1 for ozonation alone and 4.740×10^-2 min^-1 for O3/Fe_(3)O_(4)-CoO/Al_(2)O_(3).And O3/Fe_(3)O_(4)-CoO/Al_(2)O_(3)had a larger Rot(6.614×10^-9)calculated by the relative method than O3 did(1.800 x 10-9),showing O3/Fe_(3)O_(4)-CoO/Al_(2)O_(3)generated more hydroxyl radical.Similar results were also obtained in the catalytic ozonation of nitrobenzene and oxalic acid.The above results demonstrated that the catalytic performance of Fe_(3)O_(4)-CoO/Al_(2)O_(3)in ozonation of studied organic substance was universal to a certain degree.
基金
supported by the National Natural Science Foundation of China(No.50578146,20876151)
the National Science Foundation of Zhejiang Province,China(No.Y5080178)
