DDTC改性磁性纳米Fe_(3)O_(4)对水中镉的吸附行为  

Absorption Behavior of Cadmium in Aqueous Solution by DDTC Modified Magnetic Nano-Fe_(3)O_(4)

作　　者：郭晓婧 张志毅 郭掌珍[1] 吴瑜 GUO Xiao-jing;ZHANG Zhi-yi;GUO Zhang-zhen;WU Yu(College of Resources and Environment,Shanxi Agricultural University,Taigu 030801,China)

机构地区：[1]山西农业大学资源环境学院,山西太谷030801

出　　处：《中国给水排水》2021年第9期57-64,74,共9页China Water & Wastewater

基　　金：山西省土壤环境与养分资源重点实验室开放基金资助项目(2017003);山西省自然科学基金资助项目(2015011082)。

摘　　要：采用二乙基二硫代氨基甲酸钠(DDTC)改性磁性纳米材料Fe_(3)O_(4),制得一种新型磁性纳米材料(DDTC-MNPs),并用于吸附重金属Cd^(2+)。借助扫描电镜(SEM)、X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)、热重分析仪(TG)等手段对其进行表征,采用批量吸附实验考察了该材料对Cd^(2+)的吸附性能。结果表明,DDTC-MNPs粒径约为20 nm;其对Cd^(2+)的去除率随溶液pH值的增加而增加,在较广的pH值范围(3.0~7.0)对Cd^(2+)实现有效吸附;共存离子K^(+)、Na^(+)、Ca^(2+)和Mg^(2+)会对DDTC-MNPs吸附Cd^(2+)产生一定影响,但仍能保持良好吸附效果;吸附动力学表明,DDTC-MNPs对Cd^(2+)的吸附在10 min内基本达到平衡,符合准二级动力学;等温吸附符合Langmuir模型(R^(2)>0.97),表明该吸附为单分子层化学吸附,理论最大吸附量为21.74 mg/g;DDTC-MNPs对Cd^(2+)的吸附热力学参数ΔG0<0、ΔH0<0、ΔS0<0,表明吸附反应为自发放热反应;经吸附-解吸4次后,DDTC-MNPs对Cd^(2+)的去除率仍高于70%。A novel adsorbent(DDTC-MNPs)was prepared by modifying magnetic nano-Fe_(3)O_(4)with sodium diethyldithiocarbamate(DDTC),which was employed to adsorb heavy metal Cd^(2+).The properties of DDTC-MNPs were characterized by SEM,XRD,FTIR and TG,and Cd^(2+)adsorption capacity of the material was investigated by batch adsorption experiments.The results showed that the particle size of DDTC-MNPs was about 20 nm.The removal efficiency of Cd^(2+)by DDTC-MNPs increased with the increase of pH,and effective adsorption was achieved in a wide range of pH(3.0-7.0).The presence of K^(+),Na^(+),Ca^(2+)and Mg^(2+)had a certain impact on the adsorption of Cd^(2+),but it could still keep good adsorption effect.Adsorption kinetics showed that the adsorption of Cd^(2+)by DDTC-MNPs reached equilibrium within 10 min,which was in line with the pseudo-second-order model.Isothermal adsorption conformed to the Langmuir model(R^(2)>0.97)with the maximum theoretical adsorption capacity of 21.74 mg/g,indicating that the adsorption was a monolayer chemical adsorption.The Cd^(2+)adsorption thermodynamic parameters of DDTC-MNPs,namelyΔG0,ΔH0 andΔS0,were all less than zero,indicating that the adsorption reaction was spontaneous thermal reaction.The removal efficiency of Cd^(2+)was still larger than 70%after four times of adsorption and desorption.

关 键 词：二乙基二硫代氨基甲酸钠 磁性纳米材料 Fe_(3)O_(4) 镉 吸附 改性 

分 类 号：TU992[建筑科学—市政工程]