摘要
将改进Hummers法合成的氧化石墨烯(GO)与废茶渣(TW)、Fe_(3)O_(4)进行复合获得废茶渣磁性改性物rGO/Fe_(3)O_(4)/TW,通过FTIR光谱和XRD对产物结构和晶型进行表征。考察溶液pH值、振荡时间和铀初始浓度对合成产物吸附行为的影响。采用孔结构分析仪和XPS对rGO/Fe_(3)O_(4)/TW吸附前后样品的孔特性和表面结构进行吸附机理分析。结果表明,rGO/Fe_(3)O_(4)/TW不仅具有优良的去铀性能,短时间内可达近100%的去除率,而且负载铀之后通过磁场作用易从液相中快速分离出来。rGO/Fe_(3)O_(4)/TW对铀的吸附过程符合Langmuir模型和准二级动力学模型。对于初始浓度为10 mg/L的含铀溶液,TW、MTW和rGO/Fe_(3)O_(4)/TW的最大吸附量分别为97.70 mg g^(-1)、79.46 mg g^(-1)和103.84 mg g^(-1)。同时,rGO/Fe_(3)O_(4)/TW具有良好的循环再利用性,经5个吸附-解吸-再吸附循环之后,仍可达到较好的去铀效果,去铀率约为85%。
Used tea leaves,or tea waste(TW),were crushed into powder and mixed with graphene oxide(GO)in water,followed by adjusting the pH value of the resulting suspension with ammonia to 11,adding FeCl_(2)·4H_(2)O under magnetic stirring,filtration and drying to prepare a rGO/Fe_(3)O_(4)/TW(with mass ratios of 1∶2∶1)hybrid material.The structure and crystalline phases of the material were characterized by FTIR and XRD.Isotherms for uranium adsorption were obtained and its kinetics were measured in a conical bottle that was placed in a shaker.The effects of the pH value of the uranium solution,adsorption time and initial concentration on the uranium adsorption were investigated.Results indicate that the hybrid has a much faster adsorption rate than TW with an uranium removal rate up to nearly 100%in 20 min for an initial uranium concentration of 10 mg L^(-1).The maximum adsorption capacity of the hybrid is 103.84 mg g^(-1) while that of TW is 97.70 mg g^(-1).The hybrid with adsorbed uranium can be easily separated from the solution by applying a magnetic field.The isotherms and kinetics of uranium adsorption on the hybrid are best fitted by the Langmuir isotherm model and the pseudo-second-order model,respectively.The hybrid has good reusability with an uranium removal rate of about 85%after 5 cycles.
作者
杨爱丽
杨胜亚
朱玉宽
YANG Ai-li;YANG Sheng-ya;ZHU Yu-kuan(Institute of Materials,China Academy of Engineering Physics,Jiangyou 621907,China)
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2021年第4期821-826,共6页
New Carbon Materials
基金
国家自然科学基金项目(No.21407132)
中国工程物理研究院环保基金项目(No.YAHZY-2018-008).
关键词
废茶渣
氧化石墨烯
磁性改性
吸附
铀
Tea waste
Graphene oxide
Magnetic modification
Adsorption
Uranium
