聚多巴胺改性碳纳米管对Pb^(2+)的吸附性能

Adsorption Performance of Polydopamine-modified Carbon Nanotubes for Pb^(2+) Ions

研究了聚多巴胺改性碳纳米管对水溶液中Pb2+离子的吸附性能,考察了初始pH和吸附时间对该吸附过程的影响.该过程的吸附动力学符合准二级动力学模型,通过Langmuir吸附等温式描述更为合适,属于单分子层吸附.同时,对聚多巴胺改性前后的碳纳米管吸附Pb2+的能力进行了对比研究.结果表明,多巴胺改性的碳纳米管对Pb2+的吸附性能优于原始碳纳米管,平衡吸附量可达34.0mg/g.

Adsorption properties of polydopamine-modified carbon nanotubes （CNTs@ PDA） for Pb2＋ ions were investigated. The influences of the initial pH and contact time on the adsorption process were studied. The adsorption kinetics within the pseudo-second-order model and Langmuir isotherm model was well suitable for the adsorption process, suggesting that the adsorption was a monolayer process. Meanwhile, the contrastive study was carried out about the Pb2＋ adsorption capacity of carbon nanotubes before and after modification by polydopamine. The results showed that the CNTs@PDA exhibited better adsorption ability for Pb2＋ ions than pristine CNTs and equilibrium sorption capacity of the CNTs@PDA was 34.0 mg/g.