水中全氟化合物的活性炭吸附特性研究  

Study on adsorption characteristics of perfluorinated compounds on activated carbon

作　　者：孙博[1,2] 马军[1,2] 

机构地区：[1]哈尔滨工业大学市政环境工程学院,哈尔滨150090 [2]城市水资源与水环境国家重点实验室,哈尔滨150090

出　　处：《给水排水》2017年第2期14-18,共5页Water & Wastewater Engineering

基　　金：国家自然科学基金面上项目(51378141)

摘　　要：针对5种具有不同碳氟链长度的全氟羧酸,选择了4种不同基质的活性炭,开展了活性炭吸附水中全氟羧酸污染物特性的研究。在试验所使用的4种活性炭中,以椰壳和木材为基质的活性炭对全氟羧酸的吸附能力最强。通过水磨法将粉末活性炭制备为超微粉末活性炭(粒径约为1.2μm)后,其吸附容量没有明显变化,仅吸附效率得到了显著提高,在吸附开始的5min内即能够达到吸附平衡。碳氟链长度与活性炭吸附水中全氟羧酸的效果密切相关,全氟羧酸的碳氟链长度越长,其亲水性越弱,活性炭对其的吸附效果越好。当水中pH和离子强度分别为7.2和0.02时,15mg/L的椰壳活性炭能够吸附90%初始浓度为500ng/L的全氟辛酸,但仅能去除水中不高于10%的全氟丁酸。根据试验结果,较低的pH有利于全氟羧酸的活性炭吸附,水中的离子强度与可溶性有机物能够抑制全氟羧酸的吸附去除。In this study, experiments were conducted to investigate adsorption of five homolo- gous perfluoroalkyl acids on activated carbons prepared from four different raw materials. Among the four kinds of activated carbons applied in this study, coconut shell and wood activated carbons showed the highest adsorption capacity for perfluorocarboxylic acids. The powder activated carbon was converted to ultrafine activated carbon by wet-milling （~ 1.2μm）. This only resulted in sig- nificantly improved adsorption rate, which could reach adsorption equilibrium within 5 minutes, but the adsorption capacity did not change significantly. The perfluorocarboxylic acids adsorption on activated carbon was closely related to the length of the fluorocarbon chains. The longer the C-F chains the perfluoroalkyl acids contained, the weaker the hydrophilicity they displayed, and the more effectively they could be adsorbed by activated carbon. When the pH and ionic strength were 7.2 and 0.02 respectively, more than 90% of the initial 500 ng/L PFOA could be adsorbed by 15 mg/L coconut shell powdered activated carbon, but only less than 10% of PFBA in water could be removed. The results showed that lower pH value could enhance the adsorption of perfluoroal- kyl acids, but NOM and higher ionic strength could hinder the adsorption.

关 键 词：全氟化合物 全氟羧酸 活性炭 吸附 

分 类 号：TU991.2[建筑科学—市政工程]