摘要
借助高效液相色谱紫外检测器法(HPLC-UV),研究了不同pH和温度条件对双草醚钠盐水解的影响,以期为指导双草醚钠盐的合理使用以及评价其环境特性提供科学依据,并为处理该除草剂废水的进一步研究提供基础参数。结果表明,双草醚钠盐的水解速率和机制受其化合物本身的结构和介质的酸碱度影响很大。双草醚钠盐在酸性条件下易水解,酸能催化双草醚钠盐的水解,且随着pH值的降低水解速度加速,当pH为3和5时,双草醚钠盐的水解半衰期分别为2.61、36.67d。双草醚钠盐在中性和弱碱性条件下水解缓慢,当pH为7和9时,双草醚钠盐表现得相当稳定,25℃下经过30d的水解反应均未超过10%,而强碱性环境下的水解速度明显加快。温度升高有利于双草醚钠盐的水解反应,pH4时水解活化能为58.367kJ·mol-1,温度效应为2.6。
Effects of pH and temperature on the hydrolysis of bispyribae-sodium in aqueous solutions were investigated in this paper. The pH rate profiles for hydrolysis of bispyribac-sodium were obtained at 298K and the pH ranged 3-11. The half -lives in buffer solutions with different pH values were 2.61 d, 36.67 d, 288.75 d, 266.54 d and 4.10 d, respectively. Bispyribac-sodium was readily decomposed in acid buffer solutions. The degradation rate was quicker as the pH was lower. Bispyribae-sodium was stable in basic and neutral buffer solutions. but its hydrolysis rate accelerated with rising pH value. In addition, the higher temperature accelerated the hydrolysis rate in the range of 288K to 318K in acid buffer solutions. The activation energy of hydrolysis of bispyribae-sodium is 58.367 kJ·mol^-1 （pH=4）. And temperature coefficient was 2.6. The results showed that the herbicide bispyribac-sodium was not stable in aqueous solutions, and the pH value and temperature had maked significantly influence on the degradation rate of bispyribac-sodium. Such results provided the theoretical basis of environmental effects for the treatment of the bispyribac-sodium wastewater.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2006年第2期494-496,共3页
Journal of Agro-Environment Science
关键词
双草醚钠盐
水解
PH
温度
bispyribac-sodium
hydrolysis
pH
temperature
