The photocatalytic degradation of methyl orange(MO)in UV/Supported-TiO2 system was investigated and a kinetic model was presented.The experimental results show that the photocatalytic degradation rate is favored by hi...The photocatalytic degradation of methyl orange(MO)in UV/Supported-TiO2 system was investigated and a kinetic model was presented.The experimental results show that the photocatalytic degradation rate is favored by high concentration of dye in solution and is enhanced by the solution temperature.A simple kinetic model has been proposed which can describe the discoloration process in an adequate way.The calculated results obtained were in good agreement with experimental data.The model predicts the concentration of MO during the photocatalytic degradation process.展开更多
The present study evaluated calcined Mg/Al layered double hydroxide(CLDH)availability for the removal of fluoride from local groundwaters.The Mg/Al layered double hydroxide(LDH)was synthesized by coprecipitation metho...The present study evaluated calcined Mg/Al layered double hydroxide(CLDH)availability for the removal of fluoride from local groundwaters.The Mg/Al layered double hydroxide(LDH)was synthesized by coprecipitation method and characterized by XRD,FT-IR and TGA-TDA analyses.Batch defluoridation experiments were performed under various conditions such as calcination,solution pH,contact time,temperature,material dosage and reuse.Experimental results indicate that fluoride removal strongly increased after calcination of the LDH up to 600℃.The maximum fluoride removal was obtained at solution pH of 6.85.Kinetics of fluoride removal followed the pseudo-second order kinetic model.The rise in solution temperature strongly enhances the removal efficiency.The adsorption mechanism involved surface adsorption,ion exchange interaction and original LDH structure reconstruction by rehydration of mixed metal oxides and concomitant intercalation of fluoride ions into the interlayer region.The optimum dosages required to meet the national standard for drinking water quality were found to be 0.29 and 0.8 g/L,respectively,for Bejaad and Settat goundwaters.A decrease in the fluoride uptake with increasing the number of regeneration cycles was observed.展开更多
文摘The photocatalytic degradation of methyl orange(MO)in UV/Supported-TiO2 system was investigated and a kinetic model was presented.The experimental results show that the photocatalytic degradation rate is favored by high concentration of dye in solution and is enhanced by the solution temperature.A simple kinetic model has been proposed which can describe the discoloration process in an adequate way.The calculated results obtained were in good agreement with experimental data.The model predicts the concentration of MO during the photocatalytic degradation process.
文摘The present study evaluated calcined Mg/Al layered double hydroxide(CLDH)availability for the removal of fluoride from local groundwaters.The Mg/Al layered double hydroxide(LDH)was synthesized by coprecipitation method and characterized by XRD,FT-IR and TGA-TDA analyses.Batch defluoridation experiments were performed under various conditions such as calcination,solution pH,contact time,temperature,material dosage and reuse.Experimental results indicate that fluoride removal strongly increased after calcination of the LDH up to 600℃.The maximum fluoride removal was obtained at solution pH of 6.85.Kinetics of fluoride removal followed the pseudo-second order kinetic model.The rise in solution temperature strongly enhances the removal efficiency.The adsorption mechanism involved surface adsorption,ion exchange interaction and original LDH structure reconstruction by rehydration of mixed metal oxides and concomitant intercalation of fluoride ions into the interlayer region.The optimum dosages required to meet the national standard for drinking water quality were found to be 0.29 and 0.8 g/L,respectively,for Bejaad and Settat goundwaters.A decrease in the fluoride uptake with increasing the number of regeneration cycles was observed.
