Study on Degradation of Cylindrospermopsin by Chlorine Dioxide

LI Shaoxiu; LI Zhijun; ZHU Luyao; ZHAO Dejun; WANG Zhihong; LI Dongmei; XIE Baohong

doi:10.3969/j.issn.1003-6504.2017.01.011

Abstract：Degradation effects of cylindrospermopsin (CYN) were investigated experimentally under different dosages of chlorine dioxide,initial concentration of CYN,pH value and temperature.The reaction dynamics of CYN degradation by C1O2 was discussed.The results showed that C1O2 degraded CYN effectively.Degradation rate of CYN increased with the increase of the dosage of chlorine dioxide.When the initial concentration of CYN was below 15.11 μg/L,it was not obvious that the initial concentration of CYN influenced on the degradation of CYN.However,the degradation rate of CYN increased with the increase of initial concentration of CYN above 15.11 μg/L.Moreover,degradation rate of CYN at the temperature of 25 ℃ was close to that at 30 ℃,both of them were higher than that at 15 ℃.In acidic condition,degradation rate of CYN was higher than that in alkaline and neutral conditions.Therefore,at the temperature of 25 ℃,when pH value was 7.05,initial concentration of CYN was 28.04 μg/L and dosage of C1O2 was 0.5 mg/L,degradation rate of CYN was 83.69％ at 30 min and 92.62％ at 120 min,respectively.Degradation of CYN by C1O2 was the third order reaction with the rate constants at 30 ℃,25 ℃ and 15 ℃ as 9.30x10-4 L2/(μg2·s),9.90x10-4 L2/(μg2·s) and 9.83×10-5 L2/(μg2·s),respectively.The reaction activation energy was 12.29 kJ/mol and the degradation reaction took place rapidly at normal temperature.