The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount...The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g,, it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84--24 mg/m^3 by O3/TiO2flJV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m^3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/（m^3.min） and Langmuir adsorption coefficient K of 0.0268 m^3/mg were obtained.展开更多
[Objective] The paper aimed to study on the effects of photocatalytic degradation of microcystins MC-RR and MC-LR by UV/Fenton/TiO2 in depth lake water.[Method] With Fenton-TiO2 as photocatalyst,the influences of diff...[Objective] The paper aimed to study on the effects of photocatalytic degradation of microcystins MC-RR and MC-LR by UV/Fenton/TiO2 in depth lake water.[Method] With Fenton-TiO2 as photocatalyst,the influences of different reaction time,initial pH value,H2O2 concentration,Fe2+ concentration,TiO2 dosage,light intensity,initial concentration of microcystin on UV/Fenton/TiO2 heterogeneous photocatalytic degradation of microcystin were investigated,and removal effects of microcystin between heterogeneous photocatalytic degradation and UV photolysis were compared at the same time.[Result] Under the conditions that the initial concentration of H2O2 was 0.1 mmol/L,[H2O2]/[FeSO4] was 15:1,pH value was 4.0,the distance between the reaction solution and UV lamp tube was 1 cm,TiO2 dosage was 0.05 g/L,reaction temperature was (16±2) ℃,the removal rate of MC-RR with concentration of 0.35 mg/L and MC-LR with concentration of 0.29 mg/L could reach 91.5% and 90.2% after 3 minutes reacting.[Conclusion] UV/Fenton/TiO2 photocatalytic oxidation was proved to be effective in degradating microcystins.展开更多
This research focused on the feasibility and treatment efficiency of Advance Oxidation Process(AOP)-UV/TiO2 for three different kinds of simulated dye wastewater(FBL,FBB and S-RL).The first part of this study investig...This research focused on the feasibility and treatment efficiency of Advance Oxidation Process(AOP)-UV/TiO2 for three different kinds of simulated dye wastewater(FBL,FBB and S-RL).The first part of this study investigated the treatment of simulated dye wastewater with UV/TiO2 by changing TiO2 dosages,TiO2 particle sizes and dye concentrations.The efficiency was measured by color removal and TOC removal.The optimum conditions obtained for treatment of different dye wastewater were different.The treatment of Indanthrene red(FBB) by UV/TiO2 was the best,with 99.68% of TOC removal percentage and nearly 100% of color removal while treatment of FBL with 96.11% of TOC removal and almost 100% of color removal.The removal efficiency was lowest for S-RL dye solution with 81.88% of TOC and 95.87% for color removal.Both Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model(modified L-H model) were fitted to the experimental data and were able to correlate the adsorption patterns and the kinetics of the dyes studied.Since the photocatalysts(TiO2) used were nano-sized powder and is difficult to separate from the wastewater,the second part of this research focuses on the preparation of TiO2-film on glass-substrate and the treatment of simulated FBL dye wastewater by UV/TiO2-film oxidation then followed.The experimental results showed the TiO2-films are suitable only for the dye wastewater treatment in low concentration.展开更多
The UV/Ag-TiO2/O3 process was investigated for ballast water treatment using Dunaliella salina as an indicator. Inactivation curves were obtained, and the toxicity of effluent was determined. Compared with individual ...The UV/Ag-TiO2/O3 process was investigated for ballast water treatment using Dunaliella salina as an indicator. Inactivation curves were obtained, and the toxicity of effluent was determined. Compared with individual unit processes using ozone or UV/Ag-TiO2, the inactivation efficiency ofD. salina by the combined UV/Ag-TiO2/O3 process was enhanced. The presence of ozone caused an immediate decrease in chlorophyll a （chl-a） concentration. Inactivation efficiency and chl-a removal efficiency were positively correlated with ozone dose and ultraviolet intensity. The initial total residual oxidant （TRO） concentration of effluent increased with increasing ozone dose, and persistence of TRO resulted in an extended period of toxicity. The results suggest that UV/Ag-TiO2/O3 has potential for ballast water treatment.展开更多
基金Project supported by the Science Project of Harbin City(No. H2001-12)the Youth Foundation of School of Municipal and Environmental Engineering in Harbin Institute of Technology(No. 01306914).
文摘The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g,, it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84--24 mg/m^3 by O3/TiO2flJV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m^3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/（m^3.min） and Langmuir adsorption coefficient K of 0.0268 m^3/mg were obtained.
基金Supported by the Social Development Scientific and Technolgical Project[GKHS-2007-1007]The Special Funds for Top Talents [GSZH-2007-108]The Special Project for Improving Researeh Conditionsof Guizhou [TZJF-2007-15]
文摘[Objective] The paper aimed to study on the effects of photocatalytic degradation of microcystins MC-RR and MC-LR by UV/Fenton/TiO2 in depth lake water.[Method] With Fenton-TiO2 as photocatalyst,the influences of different reaction time,initial pH value,H2O2 concentration,Fe2+ concentration,TiO2 dosage,light intensity,initial concentration of microcystin on UV/Fenton/TiO2 heterogeneous photocatalytic degradation of microcystin were investigated,and removal effects of microcystin between heterogeneous photocatalytic degradation and UV photolysis were compared at the same time.[Result] Under the conditions that the initial concentration of H2O2 was 0.1 mmol/L,[H2O2]/[FeSO4] was 15:1,pH value was 4.0,the distance between the reaction solution and UV lamp tube was 1 cm,TiO2 dosage was 0.05 g/L,reaction temperature was (16±2) ℃,the removal rate of MC-RR with concentration of 0.35 mg/L and MC-LR with concentration of 0.29 mg/L could reach 91.5% and 90.2% after 3 minutes reacting.[Conclusion] UV/Fenton/TiO2 photocatalytic oxidation was proved to be effective in degradating microcystins.
文摘This research focused on the feasibility and treatment efficiency of Advance Oxidation Process(AOP)-UV/TiO2 for three different kinds of simulated dye wastewater(FBL,FBB and S-RL).The first part of this study investigated the treatment of simulated dye wastewater with UV/TiO2 by changing TiO2 dosages,TiO2 particle sizes and dye concentrations.The efficiency was measured by color removal and TOC removal.The optimum conditions obtained for treatment of different dye wastewater were different.The treatment of Indanthrene red(FBB) by UV/TiO2 was the best,with 99.68% of TOC removal percentage and nearly 100% of color removal while treatment of FBL with 96.11% of TOC removal and almost 100% of color removal.The removal efficiency was lowest for S-RL dye solution with 81.88% of TOC and 95.87% for color removal.Both Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model(modified L-H model) were fitted to the experimental data and were able to correlate the adsorption patterns and the kinetics of the dyes studied.Since the photocatalysts(TiO2) used were nano-sized powder and is difficult to separate from the wastewater,the second part of this research focuses on the preparation of TiO2-film on glass-substrate and the treatment of simulated FBL dye wastewater by UV/TiO2-film oxidation then followed.The experimental results showed the TiO2-films are suitable only for the dye wastewater treatment in low concentration.
基金supported by the Heilongjiang Provincial Science and Technology Development Program (No.GC06C20503)
文摘The UV/Ag-TiO2/O3 process was investigated for ballast water treatment using Dunaliella salina as an indicator. Inactivation curves were obtained, and the toxicity of effluent was determined. Compared with individual unit processes using ozone or UV/Ag-TiO2, the inactivation efficiency ofD. salina by the combined UV/Ag-TiO2/O3 process was enhanced. The presence of ozone caused an immediate decrease in chlorophyll a （chl-a） concentration. Inactivation efficiency and chl-a removal efficiency were positively correlated with ozone dose and ultraviolet intensity. The initial total residual oxidant （TRO） concentration of effluent increased with increasing ozone dose, and persistence of TRO resulted in an extended period of toxicity. The results suggest that UV/Ag-TiO2/O3 has potential for ballast water treatment.
