A combined process of catalytic ozonation in the presence of a novel heterogeneous catalyst and biological activated carbon was investigated for the removal of priority control organic pollutants, the reduction of gen...A combined process of catalytic ozonation in the presence of a novel heterogeneous catalyst and biological activated carbon was investigated for the removal of priority control organic pollutants, the reduction of genotoxicity, and the improvement of biodegradable dissolved organic carbon (BDOC). Results confirm that the catalytic ozonation has higher effectiveness for the removal of refractory harmful organic pollutants, the reduction of genotoxicity and the increase of bio-degradability of organics than ozonation alone, which results in lower pollution load for subsequent biological activated carbon process, and then leads to less organic pollutants penetrating biological activated carbon. The novel catalytic ozonation with this combined process exhibits excellent performance to guarantee the safety of drinking water.展开更多
Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As effective and efficient approaches for water purificati...Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As effective and efficient approaches for water purification, Fenton＇s reagent, ozonation, electrochemical and photocatalytic methods have been widely studied and applied in different aspects and have been reviewed by several articles. In recent years, some novel catalytic processes based on above processes have been developed for enhancing the efficiency of removing the organics from water. This review emphasized on the recent development of heterogeneous catalytic ozonation, electrocatalysis in respect of novel electrodes and electro-Fenton method, photoelectrocatalysis process and photoelectron-Fenton in water purification. It was also an attempt to propose general ideas about mechanism and principle enhancing the catalytic efficiency for the degradation and the mineralization of organics in water.展开更多
Fe304 was supported on mesoporous A12O3 or SiO2 （50 wt.%） using an incipient wetness impregnation method, and Fe304/A12O3 exhibited higher catalytic efficiency for the degradation of 2,4-dichlorophenoxyace- tic acid...Fe304 was supported on mesoporous A12O3 or SiO2 （50 wt.%） using an incipient wetness impregnation method, and Fe304/A12O3 exhibited higher catalytic efficiency for the degradation of 2,4-dichlorophenoxyace- tic acid andpara-chlorobenzoic acid aqueous solution with ozone. The effect and morphology of supported Fe304 on catalytic ozonation performance were investigated based on the characterization results of X-ray diffraction, X-ray photoelectron spectroscopy, BET analysis and Fourier transform infrared spectroscopy. The results indicated that the physical and chemical properties of the catalyst supports especially their Lewis acid sites had a significant influence on the catalytic activity. In comparison with SiO2, more Lewis acid sites existed on the surface of A12O3, resulting in higher catalytic ozonation activity. During the reaction process, no significant Fe ions release was observed. Moreover, Fe304/A12O3 exhibited stable structure and activity after successive cyclic experiments. The results indicated that the catalyst is a promising ozonation catalyst with magnetic separation in drinking water treatment.展开更多
We report the catalytic properties of ultra-small β-FeOOH nanorods in ozonation of4-chlorophenol（4-CP）. XRD, TEM, EDS, SAED, FTIR and BET were used to characterize the prepared material. Interaction between O3 and ...We report the catalytic properties of ultra-small β-FeOOH nanorods in ozonation of4-chlorophenol（4-CP）. XRD, TEM, EDS, SAED, FTIR and BET were used to characterize the prepared material. Interaction between O3 and β-FeOOH was evident from the FTIR spectra.The removal efficiency of 4-CP was significantly enhanced in the presence of β-FeOOH compared to ozone alone. Removal efficiency of 99% and 67% was achieved after 40 min in the presence of combined ozone and catalyst and ozone only, respectively. Increasing catalyst load increased COD removal efficiency. Maximum COD removal of 97% was achieved using a catalyst load of 0.1 g/100 m L of 4-CP solution. Initial 4-CP concentration was not found to be rate limiting below 2 × 10^-3mol/L. The catalytic properties of the material during ozonation process were found to be pronounced at lower initial p H of 3.5.Two stage first order kinetics was applied to describe the kinetic behavior of the nanorods at low p H. The first stage of catalytic ozonation was attributed to the heterogeneous surface breakdown of O3 by β-FeOOH, while the second stage was attributed to homogeneous catalysis initiated by reductive dissolution of β-FeOOH at low p H.展开更多
基金Sponsored by the National High Technology Research and Development Program (863) of China(Grant No. 2006AA06Z306)the National Natural Science Foundation of China(Grant No.50578051)
文摘A combined process of catalytic ozonation in the presence of a novel heterogeneous catalyst and biological activated carbon was investigated for the removal of priority control organic pollutants, the reduction of genotoxicity, and the improvement of biodegradable dissolved organic carbon (BDOC). Results confirm that the catalytic ozonation has higher effectiveness for the removal of refractory harmful organic pollutants, the reduction of genotoxicity and the increase of bio-degradability of organics than ozonation alone, which results in lower pollution load for subsequent biological activated carbon process, and then leads to less organic pollutants penetrating biological activated carbon. The novel catalytic ozonation with this combined process exhibits excellent performance to guarantee the safety of drinking water.
文摘Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As effective and efficient approaches for water purification, Fenton＇s reagent, ozonation, electrochemical and photocatalytic methods have been widely studied and applied in different aspects and have been reviewed by several articles. In recent years, some novel catalytic processes based on above processes have been developed for enhancing the efficiency of removing the organics from water. This review emphasized on the recent development of heterogeneous catalytic ozonation, electrocatalysis in respect of novel electrodes and electro-Fenton method, photoelectrocatalysis process and photoelectron-Fenton in water purification. It was also an attempt to propose general ideas about mechanism and principle enhancing the catalytic efficiency for the degradation and the mineralization of organics in water.
文摘Fe304 was supported on mesoporous A12O3 or SiO2 （50 wt.%） using an incipient wetness impregnation method, and Fe304/A12O3 exhibited higher catalytic efficiency for the degradation of 2,4-dichlorophenoxyace- tic acid andpara-chlorobenzoic acid aqueous solution with ozone. The effect and morphology of supported Fe304 on catalytic ozonation performance were investigated based on the characterization results of X-ray diffraction, X-ray photoelectron spectroscopy, BET analysis and Fourier transform infrared spectroscopy. The results indicated that the physical and chemical properties of the catalyst supports especially their Lewis acid sites had a significant influence on the catalytic activity. In comparison with SiO2, more Lewis acid sites existed on the surface of A12O3, resulting in higher catalytic ozonation activity. During the reaction process, no significant Fe ions release was observed. Moreover, Fe304/A12O3 exhibited stable structure and activity after successive cyclic experiments. The results indicated that the catalyst is a promising ozonation catalyst with magnetic separation in drinking water treatment.
基金supported by the National Research Foundation of South Africa (No: 88220)the Cape Peninsula University of Technology (University Research Funding) (URF:2014)
文摘We report the catalytic properties of ultra-small β-FeOOH nanorods in ozonation of4-chlorophenol（4-CP）. XRD, TEM, EDS, SAED, FTIR and BET were used to characterize the prepared material. Interaction between O3 and β-FeOOH was evident from the FTIR spectra.The removal efficiency of 4-CP was significantly enhanced in the presence of β-FeOOH compared to ozone alone. Removal efficiency of 99% and 67% was achieved after 40 min in the presence of combined ozone and catalyst and ozone only, respectively. Increasing catalyst load increased COD removal efficiency. Maximum COD removal of 97% was achieved using a catalyst load of 0.1 g/100 m L of 4-CP solution. Initial 4-CP concentration was not found to be rate limiting below 2 × 10^-3mol/L. The catalytic properties of the material during ozonation process were found to be pronounced at lower initial p H of 3.5.Two stage first order kinetics was applied to describe the kinetic behavior of the nanorods at low p H. The first stage of catalytic ozonation was attributed to the heterogeneous surface breakdown of O3 by β-FeOOH, while the second stage was attributed to homogeneous catalysis initiated by reductive dissolution of β-FeOOH at low p H.
