摘要
利用嗜酸铁还原菌(Acidiphilium cryputum JF-5),通过生物还原技术释放膨润土中的Fe^(2+)以强化镧改性,从而得到一种新型生物镧改性膨润土。通过等温吸附实验考察生物镧改性膨润土对As(Ⅴ)的吸附效果,并与国际上商用的锁磷剂(Phoslock)进行对比,通过柱实验探讨生物镧改性膨润土在石英砂柱中的迁移行为。结果表明:(1)JF-5能够强化膨润土还原释放Fe^(2+),从而加强La^(3+)负载,低固液比(1.6 g/L)下制备生物镧改性膨润土具有最高的La^(3+)负载量(370 mg/g)。(2)生物镧改性膨润土对As(Ⅴ)的吸附行为符合Freundlich模型,最大吸附量为7.58 mg/g,与Phoslock的最大吸附量(3.08 mg/g)相比大幅提高;对As(Ⅴ)的吸附动力学过程与Phoslock相似,均能在4 h内快速去除As(Ⅴ)。(3)生物镧改性膨润土在石英砂柱中的迁移行为可以用对流扩散模型描述,在0.38、0.77、1.54 mL/min的流速下,生物镧改性膨润土在石英砂柱中的滞留量分别为3.68、3.77、2.29 mg,可见中等流速条件下溶液在石英柱中能够更充分接触介质从而提高滞留量。
A novel bio-lanthanide-modified bentonite was obtained by Acidiphilium cryputum JF-5 to release Fe^(2+)from bentonite minerals through bioreduction and further enhance lanthanide modification.The adsorption effect of bio-lanthanum modified bentonite on As(Ⅴ)was investigated through isothermal adsorption experiments,and its adsorption capacity was compared with the international commercial phosphorus locking agent(Phoslock).The migratory behavior of bio-lanthanum modified bentonite in quartz sand columns was explored through column experiments.The results showed that:(1)JF-5 could enhance the release of Fe^(2+)from bentonite and thus enhance the La^(3+)loading.The preparation of biolanthanide-modified bentonite at a low solid-liquid ratio(1.6 g/mL)had the highest La^(3+)loading quantity(370 mg/g).(2)The adsorption behavior of biolanthanide-modified bentonite on As(Ⅴ)was in accordance with the Freundlich model,and the maximum adsorption amount was 7.58 mg/g,which was substantial increased compared with Phoslock(3.08 mg/g);its adsorption kinetic process of As(Ⅴ)was similar to that of Phoslock,both of them could rapidly remove As(Ⅴ)within 4 h.(3)The mobility of bio-lanthanide-modified bentonite in quartz sand columns could be described by convective diffusion model,at flow rate of 0.38,0.77,1.54 mL/min,the retention capacity of the bio-lanthanum modified bentonite in quartz sand column was 3.68,3.77,2.29 mg,respectively,which could be seen that the solution in the quartz column under the condition of medium flow rate could be more sufficiently contacted with the medium and thus improve the retention capacity.
作者
刘琴
谌书
骆大勇
刘璟
LIU Qin;CHEN Shu;LUO Dayong;LIU Jing(College of Resources and Environment,Southwest University,Chongqing 400715;School of Environment and Resources,Southwest University of Science and Technology,Mianyang Sichuan 621010;College of Resources and Security,Chongqing Vocational Institute of Engineering,Chongqing 402260)
出处
《环境污染与防治》
CAS
CSCD
北大核心
2024年第5期645-649,658,共6页
Environmental Pollution & Control
基金
国家重点研发计划项目(No.2019YFC1803500)
重庆市自然科学基金资助项目(No.CSTB2022NSCQ-MSX1382)。
关键词
嗜酸铁还原菌
生物镧改性膨润土
柱迁移
砷吸附
acidophilic ferric reductive bacteria
bio-lanthanum modified bentonite
column migration
arsenic adsorption
