邻苯二甲酸酯复合污染对土壤微生态的影响

在实验室模拟条件下，通过测定土壤呼吸，w(PAEs)和微生物RAPD条带数，研究了邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)和邻苯二甲酸二辛酯(DOP)3种PAEs复合污染对农田土壤基础呼吸、微生物多样性的影响. 结果表明，PAEs污染初期的土壤基础呼吸被激活，但这种激活作用随着培养时间的延长而减弱，400 mg/kg组土壤基础呼吸最高；3种PAEs含量均有一定程度的下降，其中w(DEP)显著降低；试验终止时各组多样性条带的比例较预培养后有所增加(平均增加13%)；不同处理组土壤微生物群落DNA序列Shannon-Weaver指数顺序为0 mg/kg>50 mg/kg>100 mg/kg>200 mg/kg>400 mg/kg. 可见，PAEs复合污染提高了土壤基础呼吸，但降低了土壤微生物多样性. 

Effects of Combined Phthalate Acid Ester Contamination on Soil Micro-Ecology

The impacts of combined phthalate acid ester (PAE) contamination, including dimethyl phthalate (DMP), diethyl phthalate (DEP), and di-n-octyl phthalate (DOP), on farmland soil basal respiration and microbial diversity were studied by monitoring soil respiration, soil PAEs concentration and random amplified polymorphic DNA (RAPD) marker under laboratory simulation testing. The results showed that the soil basal respiration was activated by PAEs at an early stage, reaching a maximum value at 400 mg/kg PAEs treatment. However, this type of activation effect decreased with prolonged PAE exposure time. In addition, the concentration of PAEs in the soils decreased, especially the DEP concentration. The number of specific RAPD bands increased in all PAE treatments at the end of incubation, reaching 13% higher than that of the early stage of incubation. The Shannon-Weaver index of soil microbial community DNA sequence in all treatments was: 0 mg/kg > 50 mg/kg > 100 mg/kg > 200 mg/kg > 400 mg/kg. Overall, the results indicated that the combined PAE contamination in soil may stimulate soil basal respiration, but decrease soil microbial diversity.