不同活性炭对水中微量药物萘普生的吸附规律研究

从吸附平衡、吸附动力学、吸附等温式和吸附热力学等方面详细考察了煤质炭(MAC)、杏壳炭(XAC)和椰壳炭(YAC)对水中微量药物萘普生(Naproxen,NAP)的吸附去除效能和作用机理.实验结果表明,MAC、XAC和YAC对NAP的吸附平衡时间大致为24h,平衡吸附量相应分别为8.23mg·g-1、7.92mg·g-1、6.52mg·g-1;这3种活性炭对NAP的吸附过程均符合假二级反应动力学方程,且吸附速率受到膜扩散和内扩散作用的共同限制;相较而言NAP的吸附行为更符合Langmuir等温式;吸附热力学计算结果表明,MAC、XAC和YAC对NAP的吸附去除机理为化学吸附和物理吸附的共同作用,且化学吸附作用大于物理吸附;NAP在3种活性炭上的吸附作用均为自发进行的不可逆吸热反应.

Adsorption of trace naproxen in waterby different activated carbons

The capacity and mechanisms of trace naproxen (NAP) adsorption in water by coal carbon (MAC),apricot carbon (XAC) and coconut carbon (YAC) were analyzed by investigating the adsorption equilibrium,kinetics,isotherms and thermodynamics.The results showed that the adsorption equilibria for NAP were achieved at approximately 24 h for all the three activated carbons,with the equilibrium adsorption capacity of 8.23 mg·g^-1,7.92 mg·g^-1 and 6.52 mg·g^-1,respectively.The adsorption kinetics of NAP on MAC,XAC and YAC fit well with pseudo second-order equations and the adsorption rate was influenced by both boundary layer diffusion and intra particle diffusion.The adsorption isotherms with the three activated carbons had good agreements with Langmuir models.Based on the results of thermodynamic calculation,the adsorption of NAP by MAC,XAC and YAC could be resulted either chemically or physically,with the former more significant.In addition,the NAP adsorption on the three materials was shown to be a spontaneous,endothermic and irreversible process.