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

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(R^2>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.

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.