紫外线对微囊藻毒素-RR降解动力学拟合

Effect and Kinetic of Ultraviolet Degradation on MicrocystinRR

摘要:

探讨了反应时间、初始pH值、紫外线(UV)辐射强度、温度及初始质量浓度等因素对UV去除微污染水体中微囊藻毒素RR(MCRR)效果的影响.研究表明：MCRR的降解率随反应时间的延长及UV辐照度的增大而提高；pH对其降解具有重要作用，中性和弱酸性环境有利于MCRR的降解，当pH值为5时，UV对MCRR的降解效果最佳，强酸性和强碱性环境对UV降解MCRR起抑制作用；UV对MCRR的降解率随温度的升高而提高，且呈线性关系；从降解动力学角度考察，符合二级动力学模型，速率常数随MCRR溶液初始质量浓度的降低而加快.在

Abstract:

The parameters,such as reaction time,pH value,UV light intensity,temperature and initial concentration are investigated on the degradation of MCRR by ultraviolet(UV) radiation in micropolluted water,respectively.The results show that the degradation rate of MCRR is improved with the reaction time and higher UV intensity.The initial pH acted as a key factor to the degradation rate of MCRR.The neutral and weak acidic solutions were more appropriate to the degradation of MCRR,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.MCRR 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 MCRR 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%.