摘要
为了考察丝瓜络固定生物氧化锰对不同重金属离子的吸附特性,本研究将锰氧化芽孢杆菌Bacillus cereus CP133固定于经过NaOH预处理的丝瓜络表面并合成生物氧化锰,制备复合生物吸附剂LIBMOs;通过扫描电镜(SEM)和傅里叶红外变换光谱(FTIR)分析LIBMOs的表面性质;考察LIBMOs对重金属离Pb^(2+)、Cd^(2+)、Cu^(2+)和Zn^(2+)的吸附特性。结果表明,NaOH预处理改善了丝瓜络的表面性质,提高了亲水性,使其能够高效地固定Bacillus cereus CP133和生物氧化锰微粒。NaOH预处理丝瓜络固定生物氧化锰的比例明显高于未经处理的天然丝瓜络,14 d后生物氧化锰固定化比例分别为79.66%和49.39%;采用Langmuir和Freundlich模型对LIBMOs吸附重金属离子的等温吸附实验数据进行拟合的结果表明,Pb^(2+)和Cd^(2+)的吸附行为同时符合Langmuir和Freundlich模型(R2>0.95),但Langmuir模型能更好地拟合LIBMOs对4种重金属离子的吸附行为(R2>0.98)。LIBMOs对Pb^(2+)、Cd^(2+)、Cu^(2+)和Zn^(2+)理论饱和吸附量(LIBMOs 2.0 gL^(-1),pH 6.0和25℃时)分别为0.81、0.68、0.51 mmolg^(-1)和0.41 mmolg^(-1)。采用准一级动力学模型和准二级动力学模型对吸附动力学实验数据进行拟合,4种重金属离子的吸附动力学过程更符合准一级动力学模型(R2>0.95)。以上结果表明,用丝瓜络制备的LIBMOs可作为处理重金属废水的吸附剂。
The biosorption capacities of loofah sponge-immobilized biogenic manganese oxides(LIBMOs)for heavy metal ions were investigated.The manganese-oxidizing bacterium Bacillus cereus CP133 was immobilized onto NaOH-treated loofah sponge to produce biogenic manganese oxides(BMOs).Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM)analyses showed that the hydrophilicity and surface properties of the loofah sponge were improved by NaOH pretreatment.After 14 d of culture,the proportion of biogenic manganese oxides(BMOs)immobilized by the NaOH-treated loofah sponge(79.66%)was higher than that of untreated natural loofah sponge(49.39%).The Langmuir and Freundlich isotherm models were used to simulate the adsorption behaviors.On the basis of the experimental data,the adsorption behaviors of Cd^(2+)and Pb^(2+)well fitted both isotherms(R2>0.98),while those of Cu^(2+)and Zn^(2+)better fitted the Langmuir isotherm(R2>0.98)than the Freundlich isotherm.The adsorption capacities of the LIBMOs(2.0 gL^(-1),pH of 6.0,and 25℃)for Pb^(2+),Cd^(2+),Cu^(2+),and Zn^(2+)were 0.81,0.68,0.51,and 0.41 mmolg^(-1),respectively.The pseudo-first-order and pseudo-second-order models were used to simulate the adsorption kinetics.The adsorption kinetics of Pb^(2+),Cd^(2+),Cu^(2+),and Zn^(2+)by the LIBMOs could be better fitted by the pseudo-first-order model than the pseudo-second-order model,although the adsorption kinetics of Pb^(2+),Cd^(2+),and Zn^(2+)could be well fitted by both models(R2>0.95).These findings suggest that LIBMOs have a considerable potential for the removal of heavy metal ions from aqueous solutions.
作者
孟佑婷
MENG You-ting(Beijing Radiation Center,Beijing Academy of Science and Technology,Beijing 100875,China;Key Laboratory of Beam Technology of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2021年第4期859-865,共7页
Journal of Agro-Environment Science
基金
北京市科学技术研究院改革与发展经费培育类项目(PY2020HJ29)
新疆维吾尔自治区自然科学基金(2018D01C084)。
关键词
丝瓜络
重金属
吸附
芽孢杆菌
生物氧化锰
loofah sponge
heavy metals
adsorption
Bacillus
biogenic manganese oxides
