(1. 中南大學(xué) 資源與安全工程學(xué)院，長沙 410083;
2. 南華大學(xué) 鈾礦冶生物技術(shù)國防重點(diǎn)學(xué)科實(shí)驗(yàn)室，衡陽 421001)
摘 要: 采用海藻酸鈉包埋黑曲霉及活性炭粉末的方法制備固定化黑曲霉活性炭微球，利用靜態(tài)吸附試驗(yàn)研究鈾溶液的pH值、初始鈾濃度、吸附時(shí)間、黑曲霉粉末與活性炭粉末質(zhì)量的配比及固定化黑曲霉活性炭微球的投加量等因素對(duì)其吸附鈾的影響。通過對(duì)動(dòng)力學(xué)模型、等溫吸附模型進(jìn)行擬合，研究固定化黑曲霉活性炭吸附鈾的行為。采用掃描電鏡、能譜儀和紅外光譜儀分析吸附前后固定化黑曲霉活性炭微球表面的形貌、化學(xué)組成和官能團(tuán)結(jié)構(gòu)的變化，進(jìn)而探討吸附過程可能涉及的反應(yīng)機(jī)理。結(jié)果表明:固定化黑曲霉活性炭吸附鈾的最佳條件為pH 值為5.0，鈾初始濃度為1 mg/L，固定化黑曲霉活性炭微球投加量為0.3 g/L，9 h即達(dá)到吸附平衡，最大吸附量為691.7 mg/g。固定化黑曲霉活性炭吸附鈾的過程符合準(zhǔn)二級(jí)動(dòng)力學(xué)模型，相關(guān)系數(shù)為0.9994; 吸附等溫線符合Freundlich和Langmuir等溫線模型，相關(guān)系數(shù)分別為0.9875和0.9993，體現(xiàn)固定化黑曲霉活性炭對(duì)鈾的吸附模式是以單層吸附為主與多層吸附的共同作用的吸附模式。
關(guān)鍵字: 固定化;黑曲霉;活性炭;吸附鈾
（1. School of Resources and Safety Engineering, Central South University, Changsha 410083, China;
2. Key Discipline Laboratory of Defense Biotechnology in Uranium Mining and Hydrometallurgy,
University of South china, Hengyang 421001, China）
Abstract:Immobilizing Aspergillus niger activated carbon was made from Aspergillus niger and activated carbon by embedding with the Na-alginate. The effects of pH, 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 pH 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.
Key words: immobilizing; Aspergillus niger; activated carbon; uranium adsorption
