Formation and cytotoxicity of a new disinfection by-product (DBP) phenazine by chloramination of water containing diphenylamine  

作　　者：Wenjun Zhou Linjie Lou Lifang Zhu Zhimin Li Lizhong Zhu 

机构地区：[1]Department of Environmental Science,Zhejiang University,Hangzhou 310058,China [2]Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control,Hangzhou 310058,China [3]Zhejiang Water Conservancy and Hydropower College,Hangzhou 310018,China

出　　处：《Journal of Environmental Sciences》2012年第7期1217-1224,共8页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 20977079);the Key Innovation Team for Science and Technology of Zhejiang Province(No. 2009R50047);the Major Science and Technology Program for Water Pollution Control and Treatment (No.2008ZX07421-001);the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry

摘　　要：Disinfection by-products （DBPs） in drinking water have caused worldwide concern due to their potential carcinogenic effects. The formation of phenazine from diphenylamine （DPhA） chloramination was studied and its cytotoxicities for two human cancer cells were also investigated. Phenazine was detected synchronously with the consumption of DPhA by chloramination, which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine （NDPhA） from DPhA chloramination. The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0, with phenazine as the main product for DPhA chloramination at lower pH, but higher pH favored the formation of NDPhA. Thus, solution pH is the key factor in controlling the formation of phenazine and NDPhA. Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine, although increasing the chloramine concentration could speed up the reaction rate of DPhA with chloramines. The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 （bladder cancer cell lines） and HepG2 （hepatic tumor cell lines） cells with IC50 values of 0.50 and 2.04 mmol/L, respectively, and T24 cells being more sensitive to phenazine than HepG2 cells. The ICs0 values of phenazine, DPhA, and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA （IC50, 0.16 mmol/L）, suggesting that phenazine in drinking water may have an adverse effect on human health.Disinfection by-products （DBPs） in drinking water have caused worldwide concern due to their potential carcinogenic effects. The formation of phenazine from diphenylamine （DPhA） chloramination was studied and its cytotoxicities for two human cancer cells were also investigated. Phenazine was detected synchronously with the consumption of DPhA by chloramination, which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine （NDPhA） from DPhA chloramination. The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0, with phenazine as the main product for DPhA chloramination at lower pH, but higher pH favored the formation of NDPhA. Thus, solution pH is the key factor in controlling the formation of phenazine and NDPhA. Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine, although increasing the chloramine concentration could speed up the reaction rate of DPhA with chloramines. The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 （bladder cancer cell lines） and HepG2 （hepatic tumor cell lines） cells with IC50 values of 0.50 and 2.04 mmol/L, respectively, and T24 cells being more sensitive to phenazine than HepG2 cells. The ICs0 values of phenazine, DPhA, and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA （IC50, 0.16 mmol/L）, suggesting that phenazine in drinking water may have an adverse effect on human health.

关 键 词：PHENAZINE DIPHENYLAMINE disinfection by-product CHLORAMINATION CYTOTOXICITY 

分 类 号：TU991.25[建筑科学—市政工程] TH77[机械工程—仪器科学与技术]