摘要
以甲基丙烯酸和丙烯酰胺为功能单体,通过悬浮聚合法制备了氨基和羧基双功能化的磁性复合微球(Fe_3O_4@SiO_2-NH_2/COOH),并探讨了其对水溶液中Cd(Ⅱ)和Pb(Ⅱ)的吸附性能。X-射线衍射(XRD)分析表明,制备的磁性吸附剂内核为Fe_3O_4。红外光谱(FT-IR)和扫描电镜(SEM)测试表明,氨基和羧基对Fe_3O_4@SiO_2表面改性成功。吸附试验显示,Fe_3O_4@SiO_2-NH_2/COOH吸附Cd(Ⅱ)和Pb(Ⅱ)的最优pH值分别为5.0和5.5,吸附过程均符合动力学准二级模型和Langmuir吸附等温模型,吸附剂对Cd(Ⅱ)和Pb(Ⅱ)最大吸附量分别为207.807 mg/g和168.995 mg/g。实际饮用水样中Cd(Ⅱ)和Pb(Ⅱ)的吸附表明,去除率分别可达97.74%和91.44%。该磁性吸附剂对两种重金属离子吸附量大、去除率高,具有良好的实际应用潜力。
The amino and carboxyl groups co-functionalized magnetic composite microspheres（ Fe3O4@SiO2-NH2/COOH） were prepared using methacrylic acid and acrylamide as functional monomer via suspension polymerization method for removal of aquatic Cd（ Ⅱ） and Pb（ Ⅱ） ions. Fourier transform infrared spectroscopy（ FT-IR） spectra and scanning electron microscopy（ SEM） images showed that the amino and carboxyl groups were successfully modified onto Fe3O4@ SiO2 microspheres. Adsorption tests revealed that the optimal adsorption p H of Fe3O4@ SiO2-NH2/COOH for Cd（ Ⅱ） and Pb（ Ⅱ） were respectively 5. 0 and 5. 5. The adsorption data was both fitted well by pseudo second order model and Langmuir adsorption isotherm model. The calculated maximum adsorption capacity for Cd（ Ⅱ） and Pb（ Ⅱ） was 207. 807 mg/g and 168. 995 mg/g,respectively. Removal rates of 97. 74% and 91. 44% for Cd（ Ⅱ） and Pb（ Ⅱ） were achieved in real tap water samples. The as-prepared magnetic adsorbent with high adsorption capacity and high removal rate for the two heavy metal ions showed good application potential.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2017年第12期4302-4307,共6页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(31371813)
关键词
磁性微球
氨基羧基改性
核壳结构
重金属
吸附
magnetic microsphere
amino carboxyl modification
core-shell structure
heavy metal
adsorption
