螺旋藻对模拟矿山废水中稀土镱离子的吸附性能

Study on biosorption characteristics of spirulina to rare earth ytterbium ions in simulated mine wastewater

  • 摘要: 通过Zarrouk培养液获得了螺旋藻,并以其为生物质吸附剂,对模拟矿山废水中稀土镱离子的吸附性能进行研究.通过单道扫描电感耦合等离子体发射光谱(ICP-AES)、扫描电镜(SEM)、傅里叶红外光谱仪(FTIR)、多功能成像电子能谱仪(XPS)等分析方法对螺旋藻的结构和吸附性能进行研究.通过Freundlich,Langmuir,Redlich-Peterso和Dubinin-Radushkevich等温吸附模型,以及伪一级、伪二级、Elovich方程和颗粒内扩散动力学模型,对该过程的吸附动力学和热力学规律进行探讨,以了解该吸附过程的机理.结果表明:当被处理液的pH值为5、螺旋藻的剂量为2.0 g/L、初始镱离子浓度为100 mg/L和吸附时间为60 min时,螺旋藻对模拟矿山废水中的稀土镱离子的吸附去除率为77 %,且解吸附率可达到92.3 %,表明螺旋藻的吸附速率快、吸附效果较为理想.研究表明:该过程的吸附动力学行为符合伪二级动力学模型(R2>0.99),主要受化学吸附控制;且吸附等温线能较好用Langmuir方程进行模拟(R2>0.99),属于自发吸热型吸附过程.

     

    Abstract: Spirulina was obtained from Zarrouk culture solution and was used as a biomass adsorbent to study the adsorption performance of rare earth cerium ions in simulated mine wastewater. By the means of single channel sequence scanning inductively coupled plasma atomic emission spectrometric(ICP-AES), scanning electron microscope (SEM), fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), the structure and adsorption properties of spirulina was studied. The adsorption kinetics and thermodynamic laws were discussed from the adoption of Freundlich, Langmuir, Redlich-Peterso, Dubin-Radushkevich isothermal adsorption model and pseudo-first-order, pseudo-second-order, elovich equation and intra-particle diffusion model, which can be expected to understand the mechanism of the adsorption process. The adsorption results suggest that the removal rate and the desorption rate of Yb3+ from simulated mine wastewater can reach 77 % and 92.3 % respectively when pH of the treated liquid was 5, dosage of spirulina 2.0 g/L, initial concentration of ytterbium ions 100 mg/L and adsorption time 60 min. In this case, the data indicate that the adsorption rate of spirulina was fast and the adsorption effect was ideal. The adsorption kinetics was well accorded with pseudo-second-order kinetic model (R2>0.99). And the adsorption process was mainly controlled by chemical adsorption. The adsorption isotherm was well simulated by Langmuir equation (R2>0.99). The adsorption of Yb3+ from simulated mine wastewater by spirulina was a spontaneous endothermic process.

     

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