含水层介质对典型污染物的吸附/解吸特征  

Adsorption/Desorption Characteristics of Aquifer Media for Typical Pollutants

作　　者：徐丹 赵勇胜[1,2] XU Dan;ZHAO Yongsheng(College of New Energy and Environment,Jilin University,Changchun 130021,China;National Local Joint Engineering Laboratory of Petrochemical Pollution Site Control and Remediation Technology,Jilin University,Changchun 130021,China)

机构地区：[1]吉林大学新能源与环境学院,吉林长春130021 [2]吉林大学石油化工污染场地控制与修复技术国家地方联合工程实验室,吉林长春130021

出　　处：《环境科学与技术》2025年第4期1-11,共11页Environmental Science & Technology

基　　金：国家自然科学基金项目(42072270)。

摘　　要：为了更全面、系统地认识地下水中的典型重金属和有机污染物在含水层介质上的吸附/解吸特征,该文选择以阴离子基团形式存在的六价铬(Cr(Ⅵ))、以阳离子形式存在的镉(Cd(Ⅱ))、重质非水相液体类污染物中的硝基苯(NB)、轻质非水相液体类污染物中的苯(B)作为目标污染物,采用批平衡法分别研究其在粗砂、中砂和细砂3种典型含水层介质上的吸附/解吸特征。结果表明,Cr(Ⅵ)和Cd(Ⅱ)的吸附/解吸平衡时间为240 min,NB和B的吸附/解吸平衡时间为720 min;4种污染物的动力学特征均更符合准二级动力学模型(R^(2)>0.96)。Cr(Ⅵ)和Cd(Ⅱ)的等温吸附特征更符合Langmuir模型(R^(2)>0.98),属于单分子层吸附。NB和B的等温吸附特征具有较明显的线性特征,Henry、Langmuir和Freundlich模型的拟合效果均较好(R^(2)>0.96)。实验浓度范围内,Cr(Ⅵ)、Cd(Ⅱ)、NB和B的最大吸附量分别为10.9~14.5、841.8~875.2、10.6~12.6、13.7~17.6 mg/kg,最大解吸量分别为5.1~6.1、56.6~66.2、7.8~8.4、9.0~10.4 mg/kg。Cd(Ⅱ)一旦被吸附,其被解吸能力非常有限,解吸率为0.1%~7.9%,Cr(Ⅵ)、NB和B的解吸率分别为7.0%~49.6%、11.6%~73.3%和19.2%~66.1%,均有一定程度的解吸。To comprehensively and systematically understand the adsorption/desorption characteristics of typical heavy metals and organic contaminants in groundwater on aquifer media,this study selects hexavalent chromium(Cr(Ⅵ))in the form of anionic groups,cadmium(Cd(Ⅱ))in the form of cationic groups,nitrobenzene(NB)in dense non-aqueous phase liquid contaminants and benzene(B)in light non-aqueous phase liquid contaminants as target contaminants,and use batch equilibrium method to study their adsorption/desorption characteristics on three typical aquifer media:coarse sand,medium sand,and fine sand.The results show that the adsorption-desorption equilibrium time for Cr(Ⅵ)and Cd(Ⅱ)is 240 min,while the adsorption/desorption equilibrium time for NB and B is 720 min.The kinetic characteristics of the four pollutants are more in line with the quasi-second-order kinetic model(R^(2)>0.96).The isothermal adsorption characteristics of Cr(Ⅵ)and Cd(Ⅱ)are more in line with the Langmuir model(R^(2)>0.98)and belong to monolayer adsorption.The isothermal adsorption characteristics of NB and B have obvious linear features and the fitting effects of Henry,Langmuir,and Freundlich models are all good(R^(2)>0.96).Within the experimental concentration range,the maximum adsorption capacities of Cr(Ⅵ),Cd(Ⅱ),NB,and B are 10.9~14.5,841.8~875.2,10.6~12.6,13.7~17.6 mg/kg,and the maximum desorption capacities are 5.1~6.1,56.6~66.2,7.8~8.4 and 9.0~10.4 mg/kg,respectively.Once Cd(Ⅱ)is adsorbed,its desorption ability is minimal,with desorption rates ranging from 0.1%to 7.9%.However,the desorption rates of Cr(Ⅵ),NB,and B are 7.0%~49.6%,11.6%~73.3%,and 19.2%~66.1%,respectively,which all show some degree of desorption.

关 键 词：吸附/解吸 含水层介质 苯 镉 六价铬 硝基苯 

分 类 号：X523[环境科学与工程—环境工程]