螺旋藻对稀土铒离子的吸附特性研究

以螺旋藻为吸附剂，对模拟矿山废水中的稀土Er³⁺进行吸附特性研究.研究了被处理液的pH值、螺旋藻的剂量、初始Er³⁺浓度和吸附时间等因素对吸附过程的影响.通过Freundlich，Langmuir，Redlich-Peterson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.吸附结果显示：当被处理液的pH值为5、螺旋藻的剂量为2.0g/L、吸附温度为298K、初始Er³⁺浓度为100mg/L和吸附时间为60min时，螺旋藻对模拟矿山废水中Er³⁺的吸附去除率为90.73%，通过HNO₃解吸附，回收率可达97.12%，表明螺旋藻的吸附速率快、吸附和回收效果较为理想.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>0.9），属于自发吸热的吸附过程.

Adsorption characteristics of spirulina to rare earth erbium ions

In this study, the adsorption characteristics of spirulina to rare earth erbium ions (Er³⁺) in simulated mine wastewater were studied. The effects of different parameters on the adsorption process were investigated:including pH value of the treated solution, dose of spirulina, initial concentration of erbium ion, adsorption time, and so on. The adsorption kinetics and thermodynamic laws were discussed in detail with different adsorption models, such as Freundlich, Langmuir and Redlich-Peterson, Dubin-Radushkevich andpseudo first-order, pseudo-second-orderand elovich, intra-particle diffusion model. The mechanisms governing the adsorption process were more comprehensively understood. The results indicated that the adsorption rate of spirulinato rare earth erbium ions in simulated mine wastewater was 90.73% when the pH value of treated liquid was 5, dosage of spirulina was 2.0g/L, temperature of adsorption was 298K and initial Er³⁺ concentration was 100mg/L. Rate of desorption of Yb³⁺ from spirulina reached to 97.12% when it was eluted with 5mL of 0.5mol/L HNO₃ solution after 60min. The results showed that the adsorption rate of spirulina was fast, and the adsorption and recovery of Yb³⁺ were ideal. At the same time, the results indicated that the adsorption kinetics of this processis in good agreement with the pseudo-second-order kinetic model (R²>0.99); the adsorption process was mainly controlled by chemical adsorption;a better adsorption isotherm can be simulated by the Langmuir equation (R²>0.9);the adsorption is a spontaneous endothermic process.