土壤中邻苯二甲酸酯类物质的降解及其对土壤酶活性的影响

Degradation of Phthalate Esters in Soil and the Effects on Soil Enzyme Activities

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.

Phthalate esters（PAEs） are a kind of widespread toxic organic compounds in the environment.We discussed the different degradation rate of four kinds of PAEs in the soil and its impact on different soil enzyme activities.We used GC-MS methods to determine the concentration of PAEs in soil.The results showed that soil microorganisms play a major role in the degradation of PAEs.The biodegradation diagram of PAEs was accord with first-order kinetics equation.And the shorter carbon chain,the better degradation efficiency.With the high concentration of PAE30,DnOP,which has long carbon chain,the degradation efficiency is lower than that of PAE1 and PAE10,only 73% was degraded after 40 days.We use standard methods to determine the matrix enzyme activities,after adding the PAEs into soil,β-glucosidase,phosphatase,urease,protease activity have changed.Phosphatase activity decreased at first and then increased,β-glucosidase activity decreased slowly,protease activity increased at first and then decreased,the activity of urease increased gradually.After 20 days,except for β-glucosidase activity continued decreasing,the activities of others enzyme recovered gradually,and higher than the control group.