Experimental Study On Fe³⁺/TiO₂Photocatalytic Degradation Of Organics In Waste Water

People's environmental awareness is increasing,with the rapid economic development. Railway passengers produce a large number of fecal sewage every day, if it effluents real-time along the way, when the discharge is faster than the speed of natural degradation, it will bring pollution to the surrounding environment, affecting people's normal life. Firstly, high concentration fecal sewage has been collected, COD reduced from a few thousand mg/L to300-400mg/L by biological treatment, but further remove organic pollutants and color can not achieved only by biological treatment. In this paper, titanium dioxide (TiO2) photocatalytic oxidation technology and equipment is used for further treatment of refractory and high color fecal sewage, at the same time some common organic pollutants such as humic acid and phenol is also be studied.Experimental results show:aeration and flocculation has little effect to the removal of COD and color.15W UV lamp as light source and CTiO2=2g/L, the treatment was the best, after4.5h COD reduced from365.7mg/L to80.6mg/L, less than integrated wastewater discharge standard of China (100mg/L); Acidic condition is more conducive to the reaction, pH=2, after4.5h, COD reduced from370.82mg/L to60.67mg/L, the degradation rate is about84%, while color removal is also obviously; Add CH2O2=0.2ml/L, after4.5h, COD reduced from394.06mg/L to40.78mg/L, the degradation rate is about90%, color changes significantly.Photocatalytic reaction is more suitable for humic acid degradation with higher concentration, when CHA=20mg/L and CFe3+/TiO2=2g/L, after5h the degradation rate of humic acid is85.71%, the degradation rate of humic acid increases8.8%after TiO2doped with iron; Adding0.2ml/L H2O2can accelerate the speed of oxidation, when CHA=20mg/L and CFe3+/TiO2=2g/L, after2h the humic acid removal rate is94.87%, the degradation rate of humic acid increases9.5%after TiO2doped with iron.The degradation rate remained unchanged when concentration range is10-20mg/L, CFe3+/TiO2=2g/L, after5h, when the concentration of phenol is10mg/L,the removal rate is50.7%, when the concentration of phenol is20mg/L the removal rate is53%; Adding0.2ml/L H2O2can accelerate the speed of oxidation, when Cphenol=10mg/L and CFe3+/TiO2=2g/L, after5h the degradation rate of phenol is74.5%, when Cphenol=20mg/L and CFe3+/TiO2=2g/L, after5h the degradation rate of phenol is71.5%, the degradation rate of phenol increases21%after TiO2doped with iron; a qualitative analysis of phenol and it's intermediate products is made using high performance liquid chromatography and speculates that the intermediate products are catechol, resorcinol and benzoquinone.