活性炭对天然水体中甲基对硫磷和三氯乙烯的吸附特性研究

Adsorption modeling of methyl parathion and trichloroethylene onto powdered activated carbons in a natural water

采用序批式试验研究了3种粉末活性炭(PAC)对天然水体中甲基对硫磷(MP)和三氯乙烯(TCE)的吸附平衡特性,利用均相表面扩散模型(HSDM)对不同投炭量下的吸附动力学进行拟合与预测,并探讨了天然有机物(NOM)对MP、TCE在PAC上的竞争吸附效应.研究结果表明,天然水体条件下,3种PAC对MP和TCE的吸附符合Langmuir模型和Freundlich模型;MP比TCE更易于被PAC吸附;3种PAC对MP、TCE的吸附能力由大到小依次为YK炭、SL炭和JC炭;HSDM模型可以很好地对吸附动力学进行拟合,并能够有效地预测不同投炭量时的吸附动力学;天然水体中的NOM会与MP和TCE在PAC上发生竞争吸附,NOM对MP的竞争吸附作用相对TCE更为显著.

The adsorption equilibria of methyl parathion（MP） and trichloroethylene（TCE） onto three kinds of powdered activated carbon（PAC） in a natural water were studied using batch tests,and the homogeneous surface diffusion model（HSDM） was applied to fit and predict adsorption kinetics at different PAC doses.The competitive adsorption of natural organic matter（NOM） with MP and TCE on PAC is discussed.Both Langmuir and Freundlich isotherms fit well to the adsorption of MP and TCE on all three kinds of PAC.The adsorption capacities of the three kinds of PAC were in the order of YK SL JC,while the adsorption for MP was higher than that for TCE.The adsorption kinetics fit the HSDM model well,and the adsorption kinetics at different PAC doses could be predicted effectively using HSDM.NOM exhibited a competitive adsorption effect with MP and TCE.The competitive adsorption effect of NOM with MP was stronger than that with TCE.