Photocatalytic Degradation Of Simulating Compounds Of Syringyl As Lignin In Presence Of Titanium Dioxide

Paperlnaking black liquid is one of the main resource of papermaking wastewater, lignin has two characters such as uneasy degradated and low transparence.TiO₂ photodegradation technology has some charactors such as high effective,complete,little selective advantages,some contaminations can be degraded completely as CO₂,H₂O, inorganic salt.In this dissertation,we employed a cylinder photocatalytic reactor,a ultraviolet lamp as light source,and TiO₂ as catalyst to investigate degradation of simulating organic wastewater with outer refrigerant circulation and aqueous suspension photoreactor.Above all,TiO₂ was prepared by the sol-gel technique in the lab.The effects of preparation micro scale TiO₂ on the catalytic activities have been explored.The catalysts were also characterized with SEM,XRD,and hot weight and so on.The results showed the best techinical condition was temperature(25℃),pH 2-3,â…¤_{(butyl titanate)}:â…¤_(ethanol):â…¤_{(acid glacial)}:â…¤_{(pure water)}=10mL:60mL:4mL:8mL。The degradation of syringa,which was used as lignin of simulating compounds that the main contaminant in paper wastewater,has been studied with photocatalytic oxidation method.It was discussed to the factors of photo-degradability ratio included the lamphouse, pH of solution,initial concentration of methyl catechol,dosage of catalyst TiO₂, opened tolerance etc..The photo-catalytic degradation kinetic mechanism of syringe lignin(SL (OHC₆H₃(OCH₃)₂) was investigated using TiO₂ self-prepared as an activated catalyst.The results showed that the SL photo-catalytic degradation consisted two processes of adsorption and degradation.The adsorption equilibrium constant on TiO₂ surface Ka=2.754, max adsorption amount Qmax =11.468 mg.g^-1,and the kinetic equation were obtained by discussing L-H kinetic equation of SL,which was 1/r=3.675/C+0.1012.In cylindrical photocatalytic reactor,the researches were made on the characters of the syringe Lignin degradation obtained from organic wastewater,in which the suspended TiO₂ was used as activated photocatalyst and a 11w UV disinfection lamp(λ=253.3nm) as light source.The experimental results showed that the syringe could reach adsorption and desorption equilibrium on the surface of TiO₂ after 60 min dark reaction,and max adsorption amount was 16.3%;removal rate reached 52%with 12 hours illusion,then after 4 hours SL could be completely degraded.According to the ABS curve and color shade measures of functional groups,it could be estimated that the double methoxy of the syringe partly broke and became single methoxy structure like guaiacol under illustration condition. The concentration of the syringe and guaiacol were qualified analyzed by the formula simultaneous.