【摘要】 以三峡库区消落带典型土壤(紫色土)为对象,探讨消落带干湿交替过程中邻苯二甲酸二甲酯(DMP)在上覆水-间隙水-土壤之间的迁移释放特征。结果表明:土壤中DMP含量在两次淹水初期(0～2 d)明显下降,从第3天有反弹增高的趋势;间隙水、上覆水中DMP浓度总体呈现出微弱的增加、降低、再增加、再降低的振荡变化;两次落干初期(0～1 d),土壤中DMP均有不同程度的上升,在2～4 d有不同程度的下降,8～20 d时基本稳定在同一水平。土壤中初始DMP含量10～100mg·kg-1淹水后在三相间的迁移释放趋势相似,然而当土壤初始DMP含量增加至200 mg·kg-1后,上覆水DMP含量出现了与其他三组不同的变化趋势,三相间DMP的分配波动更大。准二级动力学方程可以很好地描述间隙水和上覆水中DMP向土壤中迁移的过程,相关性分析表明,间隙水和上覆水DMP浓度存在显著正相关的关系(P<0.05),而土壤与间隙水中DMP浓度呈现较弱的负相关。更多还原

【Abstract】 【Objective】This paper is to characterize dimethyl phthalate(DMP) migration and release between overlying water, pore water and soil in the water level fluctuating zone of the Three-Gorges Reservoir during the wetting-drying alternation period.【Method】For the study a flooding experimental device was designed to carry out cyclical wet-dry alternation test using the "flooding-drying" model. 【Result】DMP content was found decreasing significantly in the soil during the first days(0～2 d) of the two flooding periods, but increasing from the third day on, and fluctuating slightly in the pore water and overlying water;it displayed a rising trend to a varying extent in the soil on the first days(0～1 d) of the two drying periods, and a declining one varying in degree on the following two days(2～4 d), and then leveled off during the late period(8～20 d). Soils with initial DMP content varying in the range of 10～100 mg·kg-1, when flooded, showed a similar trend in DMP migration and release between the three phases. However, DMP content in the overlying water showed a different trend from the other three groups, and the DMP distribution fluctuated greatly in the three phases,when soil initial DMP content was 200 mg·kg-1.【Conclusion】The quasi-second-order kinetic equation can be used to well describe migration of DMP in pore water and overlying water into the soil. Correlation analysis shows a significant positive correlation(P<0.05) exists between pore water and overlying water in DMP concentration, but a mildly negative one between soil and pore water.更多还原