离子交换非织造布在电去离子技术中的应用

Application of the ion exchange nonwovens in the electrodeionization( EDI) technology

电去离子技术(EDI)是将电渗析与离子交换有机结合形成的一种新型膜分离技术,EDI膜堆的核心技术之一是填充材料的选择与应用。探讨了离子交换非织造布填充方式对膜堆电流、淡水室和浓水室出水电导率以及铜离子去除率等性能的影响。实验结果表明:采用离子交换非织造布缩短了离子的定向扩散和迁移距离,并有利于离子交换树脂的均匀填充,可明显提高离子迁移速率,使淡水室出水电导率大幅下降,浓水室出水电导率大幅上升,铜离子去除率提高;在三淡二浓膜堆结构中,全部填充离子交换非织造布的膜堆与只填充离子交换树脂的膜堆相比,其淡水室出水电导率下降至10%,浓水室出水电导率上升到10倍,淡水室出水的铜离子去除率达100%。填充非织造布的EDI装置在金属离子废水处理方面将具有广阔的应用前景。

Electrodeionization ( EDI) is a new membrane separation technology of combining electrodialysis and ion exchange.One of the core EDI techniques is the seeking and application of filling materials.The effect of the filling pattern of ion exchange nonwovens on the EDI current, the electrical conductivities of the dilute and the concentrate exit waters, and the removal of copper ions were investigated.The results indicated that ion exchange nonwovens not only shortens the distance of directional diffusion and migration of ions, but also improves the filling uniform of ion exchange resin.As a result, the rate of ion migration of EDI stack increases significantly, and thus both the conductivity of concentrate exit water and the copper ( II) removal of the dilute exit soar up substantially, while the conductivity of the dilute exit decrease remarkably.For the membrane stack constructions of three-dilute two-concentrate system, the conductivity of dilute exit water was decreased by 90% while that of the concentrate exit rised by 9 times, and the copper ion removal reached up to nearly 100%, while the construction with all ion exchange nonwovens filled was compared with that only with the ion exchange resin.This finding exposes a broad prospect of the ion exchange nonwovens in the heavy metal ions wastewater treatment.