季铵盐在海水中的降解性  

Degradability of quaternary ammonium salt in seawater

作　　者：李亚红[1] 赵小芳[1] 元昊[1] 陈冲[1] 周筝[1] 

机构地区：[1]国家海洋局天津海水淡化与综合利用研究所,天津300192

出　　处：《海洋环境科学》2016年第2期238-242,共5页Marine Environmental Science

基　　金：国家海洋局业务化项目子任务(1511412000033);国家海洋公益性行业科研专项项目(201005023-4)

摘　　要：以天然海水为实验介质,研究了季铵盐的生物降解、光降解和水解特性。结果表明,季铵盐的生物降解速率与水样含菌量相关,降解曲线呈阶梯三段式,中段细菌因受季铵盐杀灭/抑制作用含菌量降低,导致季铵盐的降解趋缓,192 h的降解率为8.93%。不同光源和温度对季铵盐的光降解速率和水解速率影响较大,kuv/kvis=188,k40℃/k20℃=4.58。季铵盐的降解主要由光降解贡献,20℃时自然光降解的k分别是生物降解和水解的1.96和4.5倍。季铵盐在海水中的生物降解、自然光降解和水解动力学均符合一级动力学模型,20℃时其速率常数k分别为0.00046、0.0009和0.0002,半衰期t1/2分别为62.8 d、32.1 d和126.0 d,降解半衰期较长,在海洋环境中的残留持久性需重视。This paper is to present our research results of degradability of quaternary ammonium salt（ QAS） in nature seawater. For our research purpose,we have conducted three experiments to study on the effect of bacteria contents,light source and temperature on the degradation rate of QAS,including biodegradation,photolysis and hydrolysis experiment. The results of our research indicate that the biodegradation curve of QAS is divided three phases along with the quantity of bacteria. The biodegradation rate is slower in the middle stages than other two stages because of the killing or inhibition effect of QAS on bacteria. The biodegradation rate is 8. 93% at 192 h. Light source and temperature could affect greatly the photolysis and hydrolysis rate of QAS. kuv/ kvisis188 and k40 ℃/ k20 ℃is 4. 58. The degradation of QAS is mainly composed of photolysis which reaction rate constants is 1. 96 and 4. 5 times of biodegradation and hydrolysis respectively at 20℃. Three types of degradation of QAS could be well fit to a first-order kinetic model,which degradation reaction rate constants are 0. 00046,0. 0009 and 0. 0002 respectively and half-life is 62. 8,32. 1and 126. 0 days respectively at 20℃. The long half-life of QAS states that it is necessary to pay attention to residual persistence of QAS in marine environment.

关 键 词：季铵盐 生物降解 光解 水解 海水 

分 类 号：TQ085.4[化学工程]