Effect and Kinetic of Ultraviolet Degradation on Microcystin-RR

The parameters,such as reaction time,pH value,UV light intensity,temperature and initial concentration are investigated on the degradation of MC-RR by ultraviolet(UV) radiation in micro-polluted water,respectively.The results show that the degradation rate of MC-RR is improved with the reaction time and higher UV intensity.The initial pH acted as a key factor to the degradation rate of MC-RR.The neutral and weak acidic solutions were more appropriate to the degradation of MC-RR,and the optimal pH value was 5 in this study.The strong acidic and alkaline solutions were inhibitory to the degradation of MC-RR.The relationship between degradation rate and temperature was linear.MC-RR was removed quickly in the lower concentration solution,and the processes conform to second-order kinetics model.At the UV light intensity 153 μW·cm-2,the MC-RR concentration decreased from 251.778 3 μg·L-1 to 0.801 2 μg·L-1within 160 min at pH 7.0 and 10 ℃,and the degradation rate was 99.68%.