植酸改性黑曲霉菌对水中U(Ⅵ)的吸附试验研究

Experimental Study on Uranium(Ⅵ) Adsorption in Water by Phytic Acid Modified Aspergillus Niger

以黑曲霉和植酸为原料,制备了富含磷酸基团的黑曲霉改性材料。试验探讨了 U(Ⅵ)的初始浓度,pH值、植酸与黑曲霉用量比、投加量等因素对植酸改性黑曲霉吸附 U(Ⅵ)的影响。试验结果表明:在pH=5,投加量为0.3 g/L, U(Ⅵ)初始浓度为5 mg/L,30 ℃的条件下,植酸改性黑曲霉菌对 U(Ⅵ)的吸附量达到16.19 mg/g,吸附时间90 min后趋于平衡。研究植酸改性黑曲霉对 U(Ⅵ)的吸附行为规律,结果表明吸附等温线符合Langmuir等温模型,以单层吸附为主;动力学模型符合准二级动力学,吸附过程主要是化学吸附。扫描电镜(SEM-EDS)和红外光谱(FTIR)等手段分析植酸改性黑曲霉吸附 U(Ⅵ)的机理,结果表明植酸成功引入黑曲霉表面,主要反应官能团为OH、PO4^3-、CONH。

The modified materials of Aspergillus niger which are rich in phosphate groups were prepared from Aspergillus niger and phytic acid.The effects of uranium(Ⅵ) initial concentration,pH value,phytic acid and Aspergillus niger dose ratio,dosage and other factors on the adsorption of uranium(Ⅵ) by phytic acid-modified Aspergillus niger were investigated.Experimental results showed these as follows When the pH=5,30 ℃,dosing quantity was 0.3 g/L,the initial concentration of uranium(Ⅵ) was 5 mg/L,phytic acid modified Aspergillus niger of U (Ⅵ) adsorption reached 16.19 mg/g and adsorption process was verging to be balanced after 90 minutes.The adsorption behavior of phytic acid-modified Aspergillus niger on U(Ⅵ) was studied,and the results showed that the adsorption isotherm was consistent with Langmuir isotherm model,with single-layer adsorption as the main adsorption.The kinetic model accords with pseudo-second order kinetic,and the adsorption process is mainly chemical adsorption scanning electron microscopy (SEM,EDS) and infrared spectroscopy (FTIR) analysis of phytic acid modified Aspergillus niger,the adsorption mechanism of Uranium (Ⅵ).The results showed that surface of phytic acid successful introduction of Aspergillus niger,main reaction functional group for OH、PO4^3-、CONH.