研究采用直径为30 cm, 高200 cm的土柱模拟地下土壤渗滤系统, 在水力负荷为4 cm·d-1的运行条件下, 综合利用三维荧光光谱技术（3D-EEM）及区域一体化（FRI）分析法研究取自地下土壤渗滤系统中不同深度处的溶解性有机物的组成及结构变化规律发现: （1）不同深度处的溶解性有机物（DOM）组成不同, 进水及0.50 m处的DOM主要由类蛋白质组成, 而其余DOM中占主导地位的物质是类腐殖酸。 （2）在有机污染物降解的过程中, DOM稳定性逐渐增强, 而且在此过程中部分难降解有机物可以被去除。 （3）增加地下土壤渗滤系统的深度不仅可以有效降低有机污染物浓度, 而且可以提高出水DOM的稳定性。

In the present study, the soil column with radius of 30 cm and height of 200 cm was used to simulate a subsurface wastewater infiltration system. Under the hydraulic loading of 4 cm·d-1, composition and transformation of dissolved organic matter (DOM) from different depths were analyzed in a subsurface wastewater infiltration system for treatment of septic tank effluent using three-dimensional excitation emission matrix fluorescence spectroscopy (3D-EEM) with regional integration analysis (FRI). The results indicate that: (1) from different depth, the composition of DOM was also different; influent with the depth of 0.5 m was mainly composed of protein-like substances, and that at other depths was mainly composed of humic- and fulvic-like substances. (2) DOM stability gradually increased and part of the nonbiodegradable organic matter can be removed during organic pollutants degradation process. (3) Not only the organic pollutants concentration was reduced effectively, but also the stability of the DOM improved in subsurface wastewater infiltration system.