自然水体生物膜、悬浮颗粒物和沉积物吸附铅、镉的热力学参数比较

采用实验室模拟的方法研究了松花江自然水体生物膜、悬浮颗粒物和沉积物吸附铅、镉的热力学规律。根据吸附热力学参数（Γ_max、k和K_d）综合比较3种固相物质的吸附能力，并讨论吸附能力存在差异的原因。结果表明：Langmuir型及Freundlich等温式可以很好地描述3种固相物质吸附热力学规律，三者吸附铅、镉的能力为生物膜>悬浮颗粒物>沉积物，生物膜、悬浮颗粒物和沉积物对铅的吸附能力均明显高于对镉的吸附能力。

Comparison of Adsorption Thermodynamics Parameters of Lead and Cadmium onto the Biofilm, Suspended Solids and Sediment

The adsorption thermodynamic characteristics of Pb and Cd onto natural biofilm, suspended solids and sediments collected from Songhua River were firstly investigated. The adsorption capacity of these three adsorbents was compared on the basis of adsorption thermodynamics parameters and the reasons of difference of adsorption capacity were also discussed. The results indicate that the classical Langmuir and Freundlich adsorption isotherm can be used to well describe the adsorption thermodyna- mics of Pb and Cd. The decreasing order of adsorption capacity of three adsorbents is in the decreasing order of biofilm, suspended solids and sediments and the adsorption capacity of Pb onto these adsorbents is significantly higher than that of Cd.