GAC对水中内分泌干扰物双酚A的吸附特性及动力学研究

On GAC adsorption characteristics and kinetics of EDCsbisphenol A in water

研究了颗粒活性炭(GAC)对水中内分泌干扰物双酚A(BPA)的吸附容量、吸附动力学及其影响因素。结果表明,GAC吸附容量大,吸附等温线符合Langmuir和Freundlich模型;吸附容量受GAC粒径的变化影响较大。Langmuir模型的最大吸附容量qm与粒径dp关系为ln(qm)=-0.5075×ln(dp)+14.07;Freundlich模型kf与dp关系为ln(kf)=-1.078ln(dp)+18.307。GAC对BPA为单分子层吸附,400min基本可达到平衡,且吸附速率变化符合拟二级动力学模型,dp与速率常数k2之间符合ln(k2)=-1.039ln(dp)-9.014;BPA初始浓度C0与k2关系式为1/k2=529.7C0-35979。

The adsorption capacity, adsorption kinetics and impact factors of endocrine disrupting chemicals （EDCs）-bisphenol A （BPA） in water on granular activated carbon （GAC） were investigated in this study. The results showed that high BPA adsorption capacity could be achieved by GAC. Moreover, the experiment results of adsorption isotherm fitted Langmuir and Freundlich model. The variation of adsorption capacity was influenced by particle diameter of GAC. The rela- tion between the biggest capacity qm Of Langmuir model and particle diameter could be expressed as： ln（qm）=-0. 507 5 ln（dp）＋ 14. 07, and the relation between the kf value of Freundlich model and particle diameter could be expressed as： ln（kf）=-1. 078 in （dp） ＋18. 307. From the adsorption kinetics experiment, the adsorption equilibrium could be achieved in 400 minutes for GAC. By the comparison between different adsorption kinetics, it could be drawn that pseudo second order model could be used to simulate the adsorption process effectively. The relation between the k2 val- ue of the pseudo second order and particle diameter could be expressed as： ln（k2）=-1. 039 ln（dp） -9. 014; while the initial concentration of BPA （Co） was l/k2 =529. 7 C0--35 979.