丝瓜络固定颤藻吸附Pb2+的动力学及机理

选取丝瓜络固定颤藻冻干灭活（Freeze-drying-inactivated Oscillatoria lutea Immobilized，FI）和干热灭活（Hot-air-inactivated Oscillatoria lutea Immobilized，HI）为吸附剂，以游离冻干灭活（Freeze-drying-inactivated Oscillatoria lutea Free，FF）和游离干热灭活颤藻（Hot-air-inactivated Oscillatoria lutea Free，HF）作对照，考察pH值、时间、Pb²⁺初始浓度和共存离子对吸附剂吸附溶液中Pb²⁺的影响及机制.结果表明，FI吸附效果优于HI及对照.pH值、时间、Pb²⁺初始浓度和共存离子对FI吸附性能的影响与对HI及对照的影响变化趋势一致；FI和HI吸附容量依赖pH值而变化，当pH值为5时，达到峰值；Pb²⁺初始浓度增加，吸附容量也随着增加，吸附平衡浓度分别为80和60mg/L；吸附平衡时间分别为90和60min；共存离子抑制吸附剂对Pb²⁺吸附，抑制强弱顺序为：Ca²⁺>Mg²⁺>K⁺>Na⁺.4种吸附剂对Pb²⁺的吸附符合准二级动力学方程，吸附过程主要受化学吸附速率影响.FI和FF吸附过程拟合适合Langmuir模型和Freundlich模型，而HI对Pb²⁺的吸附过程符合Langmuir模型，HF对Pb²⁺的吸附过程符合Freundlich模型.傅里叶红外光谱（FTIR）阐释了FI吸附Pb²⁺的主要官能团为氨基和羧基，吸附过程中发生了离子交换、静电吸引和络合作用.循环吸附实验显示了FI在工业处理Pb²⁺中具有很大应用潜力.

Kinetics and mechanism of adsorption Pb2+ by immobilized Oscillatoria lutea with loofah

Freeze-drying-inactivated Oscillatoria lutea Immobilized (FI) and Hot-air-inactivated Oscillatoria lutea Immobilized (HI) were used as adsorbents for Pb²⁺ adsorption from the solution with Freeze-drying-inactivated Oscillatoria lutea Free (FF) and Hot-air-inactivated Oscillatoria lutea Free (HF) as control samples. The effects of pH, contact time, Pb²⁺ initial concentrations and co-existing ions on adsorption capacity and the adsorption mechanism were investigated. Results showed that FI presented the best adsorption performance, which was better than HI and control samples. The pH, contact time, initial Pb²⁺ concentrations and coexisting ions influenced adsorption capacity of Pb²⁺ with the consistent trends with FI, HI and control samples. The adsorption capacities with FI and HI depended on pH, reaching the highest value at pH=5; With the initial Pb²⁺ concentrations increased, the adsorption capacity increased, and the equilibrium adsorption capacities were 80and 60mg/L, respectively; the adsorption capacities got equilibrium after 90 and 60 min contact time, respectively; and the coexisting ions were found to inhibited the adsorption of Pb²⁺ and the order of inhibition was: Ca²⁺>Mg²⁺>K⁺>Na⁺. The adsorption of Pb²⁺ by the four adsorbents followed the pseudo-second- order kinetic equation, and the adsorption process was mainly affected by the chemical adsorption rate. The experimental results revealed that the adsorption isotherm process of FF and FI was in accordance with Langmuir and Freundlich model, the Pb²⁺ adsorption process by HI followed the Langmuir model, and HF fitted the Freundlich model. The Fourier transform infrared spectroscopy measurement suggested that the main functional groups in the Pb²⁺ adsorption process with FI were amino- and carboxyl- groups. Further, the mechanisms of adsorption process involve the ion exchange, electrostatic attraction, and complexation. The cyclic adsorption results established the high potential of FI as a robust and promising adsorbent for industrial treatment of Pb²⁺.