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邻苯二甲酸酯类物质(PAEs)是一类在环境中广泛存在的有毒有机化合物,本研究探讨了不同浓度梯度的4种PAEs在土壤中的降解,及其对不同土壤酶活性的影响.用GC-MS法测定土壤溶液中PAEs的浓度,结果表明,土壤中的微生物对PAEs的降解起主要作用,对降解数据拟合发现,PAEs降解符合一级动力学方程,并且碳链越短的酯降解效果越好,降解速率越高.在相对高浓度的PAE30环境中,碳链较长的DnOP的降解效率要低于相对低浓度时的降解率,且在40 d后只能降解73%.采用标准方法测定基质酶的活性,在PAEs加入土壤之后,β-葡萄糖苷酶、磷酸酶、脲酶、蛋白酶的活性均有变化.磷酸酶的活性先降低后升高,β-葡萄糖苷酶活性缓慢下降,蛋白酶活性先升高后降低,脲酶则呈逐渐升高的趋势.但是随着胁迫时间的延长(20 d后),除了β-葡萄糖苷酶的活性继续降低,其他酶活性都逐渐恢复,并超过了对照组.
Phthalates (PAEs) are a group of toxic and organic compounds that exist widely in the environment. In this study, the degradation of four kinds of PAEs with different concentration gradients in soil and their effects on soil enzyme activities were investigated. The concentration of PAEs in soil solution was determined by GC-MS. The results showed that the soil microorganisms played a major role in the degradation of PAEs. Fitting the degradation data, it was found that the degradation of PAEs was in accordance with the first-order kinetic equation and the shorter the carbon chain The degradation of DnOP with higher carbon chain was lower than that with relatively low concentration of DnOP, and the degradation rate of DnOP was only 73% The activities of substrate enzymes were determined by standard methods, and the activities of β-glucosidase, phosphatase, urease and protease changed after the PAEs were added into the soil.The activity of phosphatase decreased first and then increased, the activity of β-glucosidase The activity of protease increased at first and then decreased, while that of urease increased gradually, but with the extension of stress time (after 20 days), the activities of other enzymes recovered gradually except that the activity of β-glucosidase continued to decrease And over it Group.