生物炭负载磁性纳米碳羟基磷灰石(CHAP-γ-Fe_(2)O_(3)/BC)去除水中U(Ⅵ)的性能与机制  

Performance and mechanism of biochar loaded magnetic nanocarbon hydroxyapatite(CHAP-γ-Fe_(2)O_(3)/BC)for the removal of U(Ⅵ)from water

作　　者：邵雄斌 谢水波 麦颖清[1] 姜培烜 SHAO Xiongbin;XIE Shuibo;MAI Yingqing;JIANG Peixuan(School of Civil Engineering,University of South China,Hengyang 421001,China;Hunan Provincial Key Laboratory of Pollution Control and Resource Technology,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学土木工程学院,衡阳421001 [2]南华大学污染控制与资源化技术湖南省重点实验室,衡阳421001

出　　处：《复合材料学报》2024年第11期6170-6182,共13页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金项目(11475080);湖南省自然科学基金项目(2021JJ30579);湖南省研究生科研创新项目(CX20230972)。

摘　　要：针对利用功能材料去除水中U(Ⅵ)的效率与纳米颗粒易团聚的问题,利用玉米秸秆、蛋壳及磁性γ-Fe_(2)O_(3),采用动态油热法和浸渍法,制备了生物炭负载磁性纳米碳羟基磷灰石(CHAP-γ-Fe_(2)O_(3)/BC)复合材料,试验考察了其性能并用于水中U(Ⅵ)的去除。当U(Ⅵ)初始浓度为5 mg/L,CHAP-γ-Fe_(2)O_(3)/BC投加量为0.1 g/L,pH值为6,温度30℃,反应时间1 h时,试验结果表明:CHAP-γ-Fe_(2)O_(3)/BC对U(Ⅵ)的最大吸附容量达324.4 mg/g,去除率达95.93%。拟二级动力学模型和Langmuir模型可较好拟合CHAP-γ-Fe_(2)O_(3)/BC对U(Ⅵ)的吸附过程,表明以单分子层化学吸附为主。材料通过表面改性技术,实现了减弱团聚的目的。复合材料在磁场中其表现出良好的分离回收和循环利用性。FTIR、XPS等表征结果证明该材料对铀的去除机制主要包括离子交换、溶解-沉淀的化学吸附作用和表面络合作用。To address the efficiency of removing U(Ⅵ)from water using functional materials and the susceptibility of nanoparticles to agglomeration,biochar-loaded magnetic nanocarbon hydroxyapatite(CHAP-γ-Fe_(2)O_(3)/BC)composites were prepared by dynamic oil-heating and impregnation methods using corn stover,egg shells,and magneticγ-Fe2O,and the experiments were carried out to investigate the performances and used for the removal of U(Ⅵ)from water.When the initial concentration of U(Ⅵ)is 5 mg/L,the dosage of CHAP-γ-Fe_(2)O_(3)/BC is 0.1 g/L,the pH value is 6,the temperature is 30℃,and the reaction time is 1 h,the experimental results show that the maximum adsorption capacity of CHAP-γ-Fe_(2)O_(3)/BC for U(Ⅵ)reaches 324.4 mg/g,and the removal rate reaches 95.93%.The proposed secondary kinetic model and Langmuir model could fit the adsorption process of CHAP-γ-Fe_(2)O_(3)/BC on U(Ⅵ)better,indicating that the monomolecular layer chemisorption is dominated.The materials are realized to attenuate the agglomeration by surface modification technique.The composite material shows good separation recovery and recyclability in the magnetic field.The characterization results of FTIR and XPS prove that the removal mechanism of uranium by this material mainly includes ion exchange,dissolution-precipitation chemisorption and surface complexation.

关 键 词：铀(U(Ⅵ)) 生物炭(BC) 碳羟基磷灰石(CHAP) γ-Fe_(2)O_(3) 化学吸附 磁性纳米复合材料 

分 类 号：TB332[一般工业技术—材料科学与工程] X703[环境科学与工程—环境工程]