摘要
采用海藻酸钠包埋黑曲霉及活性炭粉末的方法制备固定化黑曲霉活性炭微球,利用静态吸附试验研究铀溶液的p H值、初始铀浓度、吸附时间、黑曲霉粉末与活性炭粉末质量的配比及固定化黑曲霉活性炭微球的投加量等因素对其吸附铀的影响。通过对动力学模型、等温吸附模型进行拟合,研究固定化黑曲霉活性炭吸附铀的行为。采用扫描电镜、能谱仪和红外光谱仪分析吸附前后固定化黑曲霉活性炭微球表面的形貌、化学组成和官能团结构的变化,进而探讨吸附过程可能涉及的反应机理。结果表明:固定化黑曲霉活性炭吸附铀的最佳条件为p H值为5.0,铀初始浓度为1 mg/L,固定化黑曲霉活性炭微球投加量为0.3 g/L,9 h即达到吸附平衡,最大吸附量为691.7 mg/g。固定化黑曲霉活性炭吸附铀的过程符合准二级动力学模型,相关系数为0.9994;吸附等温线符合Freundlich和Langmuir等温线模型,相关系数分别为0.9875和0.9993,体现固定化黑曲霉活性炭对铀的吸附模式是以单层吸附为主与多层吸附的共同作用的吸附模式。
Immobilizing Aspergillus niger activated carbon was made from Aspergillus niger and activated carbon by embedding with the Na-alginate. The effects of p H, initial concentration of uranium, contact time, the mass ratio of Aspergillus niger powder and activated carbon powder and the dosage on the biosorption of uranium from aqueous solutions by immobilizing Aspergillus niger activated carbon were investigated. The biosorption performances of the immobilizing Aspergillus niger activated carbon for uranium(Ⅵ) were investigated by correlating the experimental datas with the kinetic models and isothermal models. The surface morphology, chemical composition, functional groups and the possible mechanism were analyzed for the immobilizing Aspergillus niger activated carbon before and after biosorption treatment by using SEM, EDS and FTIR. The results show that the best conditions of adsorption of uranium for immobilized Aspergillus niger activated carbon are that p H of 5.0, initial uranium concentration of 1 mg/L, the adsorbent dosage 0.3 g/L. The adsorption equilibrium reaches at 9 h, and the maximum adsorption quantity is 691.7 mg/g. The adsorption process of uranium(Ⅵ) of immobilized Aspergillus niger activated carbon is in accordance with the pseudo-second-order kinetics model,the correlation coefficient is 0.9994. The isothermal model is in accordance with Langmuir and Freundlich models. The correlation coefficients are 0.9993 and 0.9875, which indicating that the adsorption of uranium(Ⅵ) of the immobilized Aspergillus niger activated carbon mainly depends on the combined effect of both monolayer and multilayer adsorption model.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2016年第4期936-945,共10页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金重点资助项目(U1401231)
国家自然科学基金资助项目(11505093
51574152)
湖南省教育厅资助项目(13C800)
衡阳市科技局资助项目(2013KS31)
南华大学创新训练中心"大学生研究性学习和创新性实验计划"校级项目(201412
201422
201501)
南华大学"铀矿山岩土工程灾害预测与控制"创新团队项目(NHCXTD04)~~
关键词
固定化
黑曲霉
活性炭
吸附铀
immobilizing
Aspergillus niger
activated carbon
uranium adsorption
