臭氧氧化降解微囊藻毒素-LR的动力学研究

Study on Kinetics of MicrocystinLR Degradation by Ozonation

摘要:

采用臭氧对微囊藻毒素-LR(MCLR)进行降解试验，研究其反应动力学.取自无锡太湖流域蓝藻藻华提取藻毒素，研究了臭氧投加量、MCLR的初始质量浓度、pH值及一些阴离子作用对降解速率的影响.结果表明，臭氧氧化能有效降解MCLR，且符合准一级动力学反应.降解速率不受MCLR初始质量浓度的影响.当臭氧投加量由0.31 mg·L-1增加到1.35 mg·L-1时，MC-LR的降解速率由0.010 3 min-1提高到0.040 7 min-1.当pH值由3.08升高到10.08时，MC-LR的降解速率由0.252

Abstract:

A study was made of the degradation of microcystinLR (MCLR) by ozonation and its kinetics.The microcystins were extracted in cyanobacteria blooms from Taihu Lake in Wuxi,China.An investigation was also conducted on the effects of ozone dose，MCLR initial concentration，pH value and some anions.The results indicate that MCLR can be effectively degraded by ozonation and the reaction fits well with the firstorder kinetics.The rate constant is invariable with different MCLR initial concentrations.However,when the dosage of ozone changes from 0.31 mg·L-1 to 1.35 mg·L-1,the rate constant increases from 0.010 3 min-1 to 0.040 7 min-1.The rate constant decreases from 0.252 8 min-1 to 0.009 9 min-1 with pH value from 3.08 to 10.08.Under acidic condition,the degradation of MCLR is more sensitive to pH value.NO3 - has positive effect on the degradation of MC-LR while CO3 2- has negative effect on it,and the effects of SO4 2- and Cl- on it are not obvious.According to their effects on the degradation rate,the four anions can be arranged as NO-3,Cl-,SO2-4,CO2-3.