不同条件下菲和萘在塿土上的吸附特征研究

以平衡吸附法研究了菲和萘在塿土上的吸附行为,考察了初始浓度、温度、pH、离子强度和CaCO3对塿土吸附菲和萘的影响,Henry方程、Freundlich方程和deBoer-Zwikker极化方程被用来拟和吸附等温线。结果表明,菲和萘在塿土上的吸附等温线为非线性,Freundlich方程最符合其吸附行为。菲和萘在塿土上的吸附量随温度升高而降低,其吸附是一个放热过程;吸附自由能小于零,表明吸附过程是自发的;熵变值也小于零,说明焓变是吸附过程的驱动力。随着pH增加,塿土对菲和萘的吸附量下降;而随着离子强度增加,塿土对菲和萘的吸附量增加。CaCO对菲和萘的吸附等温线也为非线性,其对塿土吸附菲和萘具有较大的贡献。

Adsorption Characteristics of Phenanthrene and Naphthaleneon on Lou Soil

Batch adsorption experiments were employed to evaluate the adsorption characteristics of phenanthrene and naphthalene on Lou soil,the factors affected its adsorption,i.e.temperature,pH,ionic strength and CaCO3,and the fitness of adsorption equations,i.e.Henry equation,Freundlich model and deBoer-Zwikker equation were studied also.The results showed that the adsorption of both phenanthrene and naphthalene on Lou soil are non-linear style,the Freundlich equation is the best model to describe their adsorption isotherm.The adsorption of phenanthrene and naphthalene on Lou soil decreased with an increase of temperature and pH,but increased with an increase of ionic strength.The change in Gibbs free energy was less than 0 indicates the adsorption was spontaneous,the change of enthalpy was the driving force of this spontaneous adsorption due to the thermodynamic characteristics of both enthalpy decrease and entropy decrease.The adsorption of phenanthrene and naphthalene on CaCO3 were also nonlinear,and CaCO3 showed a greater contribution to adsorption of phenanthrene and naphthalene on Lou soil.