摘要
氟是人类生命活动必需的微量元素之一,但人体摄入过多的氟元素会引发氟斑牙、骨骼变形等氟中毒现象。本文以活性炭(AC)为载体,在多孔Al_(2)O_(3)纳米分散液中采用简单超声处理,得到Al_(2)O_(3)/AC复合材料。场发射扫描电镜证明Al_(2)O_(3)成功负载在AC表面,5%Al_(2)O_(3)在AC表面分布均匀。N_(2)吸-脱附测试结果表明Al_(2)O_(3)/AC复合材料的比表面积比AC有明显增加。循环伏安、恒流充放电及电化学阻抗测试结果表明Al_(2)O_(3)的掺杂可以改善AC的离子导电性,提高比电容;5%Al_(2)O_(3)/AC导电性最佳,比电容最高,在7 mmol·L^(-1) NaF溶液中为92 F·g^(-1),是AC比电容(62 F·g^(-1))的1.5倍。以Al_(2)O_(3)/AC为正极的电容去离子(CDI)脱氟测试,结果表明5%Al_(2)O_(3)/AC电极脱氟量最大,达234μmol·g^(-1),远高于纯AC的脱氟量(115μmol·g^(-1))。此外,5%Al_(2)O_(3)/AC电极对F^(-)的选择性吸附性能良好,在含F^(-)、Cl^(-)和SO_(4)^(2-)的模拟高氟地下水中采用5%Al_(2)O_(3)/AC电极对应的三组CDI池串联,可脱除80%的F^(-)、25%的Cl^(-)和56%的SO_(4)^(2-),同时经过十次F^(-)吸脱附循环后,氟去除率仍可保持81%,证明5%Al_(2)O_(3)/AC电极对F-具有良好的选择吸附性和循环稳定性。该电极材料制备简单,脱氟选择性好,在CDI过程中有望用于高氟地区地下水的净化脱氟。
Fluorine is one of the essential trace elements in human life activities,but excessive intake of fluorine will cause fluorosis such as dental fluorosis and skeletal deformation.In this paper,the Al_(2)O_(3)/AC composite material was obtained through simple sonication of activated carbon(AC)and Al_(2)O_(3) nanoparticle.Field emission scanning electron microscopy proved that Al_(2)O_(3) was successfully loaded on the AC surface with a uniform distribution at the doping amount of Al_(2)O_(3) of 5%.The results of N2 adsorption-desorption test showed that the specific surface area of the Al_(2)O_(3)/AC composite increased.Cyclic voltammetry,constant current charge discharge and electrochemical impedance measurements demonstrated the improvement of ionic conductivity and specific capacitance of the composite after Al_(2)O_(3) doping.Effect of Al_(2)O_(3) doping amount was investigated and the 5% Al_(2)O_(3)/AC electrode achieved the optimal capacity of 92 F·g^(-1) in 7 mmol·L^(-1) NaF solution,better than that on AC electrode(62 F·g^(-1)).When being applied as the anode in capacitive deionization device,the Al_(2)O_(3)/AC electrode exhibited a defluorination capacity of 234μmol·g^(-1),much higher than that on AC electrode(115μmol·g^(-1)).In addition,the 3-cell CDI stack delivered a 80% removal of F-in the simulated groundwater containing F^(-),Cl^(-)and SO_(4)^(2-),while only 25%of Cl^(-)and 56% of SO_(4)^(2-)were removed.It demonstrated the excellent selective defluorination performance.The adsorption amount of F^(-)retained 81% after 10 adsorption/desorption cycles.The electrode material is simple to prepare and has good defluorination selectivity.It is expected to be used in the purification and defluorination of groundwater in high-fluorine areas in the CDI process.
作者
蒋雯雯
聂鹏飞
胡彬
李菁菁
刘建允
JIANG Wenwen;NIE Pengfei;HU Bin;LI Jingjing;LIU Jianyun(College of Environmental Science and Engineering,State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry,Donghua University,Shanghai 201620,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2021年第5期2817-2825,共9页
CIESC Journal
基金
国家自然科学基金项目(21776045,21476047)。
