Research On The Photodegradation Of Aqueous Organometallic Compounds Using 206 Nm UV Light

The photodegradation of organometallic compounds in aqueous solution was studied using a microwave electrodeless UV lamp(irradiating mainly 206 nm UV).In this study,we chose Acetylferrocene(AFc),Triphenyltin chloride(TPT),C.I.Reactive blue 13(RB-13)as our research objectives.The effects of initial pH value,initial concentration of organometallic compounds and irradiation time on their degradation efficiency were investigated.When added hydrogen peroxide in the solution of organometallic compounds,using 206nm UV/H₂O₂ combined photolysis technology, the degradation ratio increased.On the basis of the analysis of photoproduct with a gas chromatography-mass spectrometry(GC-MS),the likely degradation mechanism of organometallic compounds was discussed in detail.A weak acidic condition was preferred for the degradation of TPT.The lower of the initial concentration of TPT,the higher of the degradation ratio.For 120 mg·L^-1 TPT at pH=2.0,the degradation ratio of TPT was nearly 89.4%after irradiation for 75min.And the efficiency of CODcr removal and TOC removal were only 55.2%and 40.6%respectively.When added hydrogen peroxide in the solution of TPT,the degradation ratio reached 100%nearly.The degradation ratio of RB-13 increased with increasing pH value.The lower of the initial concentration of RB-13,the higher of the degradation ratio.For 40 mg·L^-1 RB-13 at pH=8.0,the degradation ratio of RB-13 was nearly 67.1%after irradiation for 180min.And the efficiency of CODcr removal and TOC removal were only 55.2% and 40.6%respectively.When added hydrogen peroxide in the solution of TPT,the degradation ratio increased.The degradation ratio of AFc decreased slowly with increasing pH value.The lower of the initial concentration of AFc,the higher of the degradation ratio.For 160 mg·L^-1 AFc at pH=6.0,the degradation ratio of AFc was nearly 90%after irradiation for 6min.And the efficiency of CODcr removal and TOC removal were only 20.8% and 13.2%respectively.When added hydrogen peroxide in the solution of AFc, the degradation ratio reached 100%nearly after irradiation for 4min.In a word,the effect of initial pH on the degradation ratio of organometallic compounds was much different.Degradation ratio decreased with the increase of initial concentration of organometallic compounds.And degradation ratio of three kinds of organometallic compounds followed the order:AFc＞TPT＞RB-13.In addition,we investigated their CODer removal and TOC removal in order to explore the feasibility of this technology,finding that the efficiency of CODer removal and TOC removal were much lower than the degradation ratio after irradiation for same time.