水环境中典型纳米颗粒对菲的吸附特征

以典型三环多环芳烃菲为代表,选取11种典型纳米颗粒对水中不同浓度的菲进行吸附实验,探究水体中的纳米颗粒对菲的吸附特征.结果表明,Freundlich模型对所有样品的拟合结果最好.logKFr值显示,有机膨润土及3种炭黑对菲的吸附作用最强,且远远大于其他纳米颗粒.有机膨润土对菲的吸附表现为线性吸附(n=1.08),而3种炭黑均表现出显著的非线性特征(n＜0.5),且非线性特征随吸附能力的增强而增强,其他几种纳米颗粒均表现出非线性吸附特征(n＜0.9).水中所有的纳米颗粒在与菲作用的过程中,吸附的强弱与颗粒表面电位、粒径及比表面积均无显著相关性,即对于所有纳米颗粒来说,这几种性质并不是决定吸附作用的最主要因素,而吸附剂的化学组成及结构特性可能是引起吸附作用差异的主要原因.

Adsorption of phenanthrene on typical nanoparticles in aquatic system

Phenanthrene was chosen as a probe PAH, and its sorption on typical nanoparticles (NPs) in aquatic system was investigated. The results showed that the Freundlich isotherms fit to the experimental sorption data best for all the NPs. Among all the NPs, the organo-bentonite and carbon black showed relatively high sorption capacities of phenanthrene. Organo-bentonite sorption isotherm appeared linear (n=1.08), while carbon black showed a significant nonlinear sorption characteristics (n<0.5) with their nonlinearity increasing with the increasing sorption capacities. All of other NPs showed nonlinear sorption (n<0.9). The sorption capacities showed no significant correlation with zeta-potential, particle sizes and BET of all the NPs, inferring complex factors that determine the sorption of PAHs to NPs. We considered that chemical composition of each adsorbent could be one of the major factors that controlled its sorption behavior in the aquatic system.