Study On TiO₂/Sepiolite Photocatalytic Oxidation Degradation Of Dyeing Waste Water

TiO₂photocatalysis oxidation degradation of printing and dyeingwastewater becomes very popular in science research in recent years.It isa new-style pollution treating approach,whose virtues are high treatmentefficiency, and chemical stability,etc.However,there is great difficulty inseparating and reusing TiO₂powder,and the loss of active component israther great.As new environmental-friend material,loaded TiO₂catalystagrees with sustainable development,and it will play an important act inthe environmental protection,such as waste water treatrnent.In this paper,modified sepiolite was prepared by the way of acidicmodification,and natural sepiolite acted as the material.The results ofoptimum condition for modification of sepiolite showed that,thetreatment acid was nitric acid，the treatment concentration of the acid was15％,the processing time was12h.Using modified sepiolite acted assubstrate,by tetrabutyl titanate as titanium source, used the sol-gel methodto prepare1#TiO₂supported catalyst;by titanium sulfate as titaniumsource,used the powder sintering method to prepare2#TiO₂supportedcatalyst.X-ray analysis and SEM show that these catalysts have favorablephotocatalysts character,they are the catalyst that is economical and hasgood capability.Photocatalysis experiment was carried out to degrade acid red Bsolution by1#and2#TiO₂supported catalyst.Under optimumcondition,the removal rate of acid red B and COD was95.73%and87.62%respectively by1#catalyst,and93.65%and84.47%respectivelyby2#catalyst.The result showed that both1#and2#TiO₂supportedcatalyst had an excellent effect on degradation of acid red B.The photocatalysis degradation reaction kinetics shows that the acidred B degradation process by photocatalyst1#and2#TiO₂supportedcatalyst respectively accords with dynamics model of L-H equation.Theexperiment proved that the decomposing of acid red B exhibitedone-garde reaction under low concentration and zero-grade reaction underhigh concentration.Their rate constants are3.925（L/min）and4.51 （L/min）respectively.Their adsorption equilibrium are1.15×10^-2（L/mg）and8.73×10^-3（L/mg）respectively.Reclaiming and repeated use of photocatalyst1#and2#TiO₂supported catalyst was studied.The removal rate of acid red B and CODwas55.13%and51.26%respectively by1#catalyst repeated using5time,and48.13%and41.64%respectively by2#catalys repeated using5time.The experimental results show that the photocatalyst can be reclaimeand repeated using after one photocatalysis charaeter.