脱盐层结构对反渗透膜碳酸钙结垢的影响研究

Effect of active layer structure on calcium carbonate scaling in reverse osmosis membrane systems

碳酸钙是常见的无机盐结垢形式,其可能导致膜通量和运行寿命降低,是反渗透系统中亟需解决的关键问题之一.本文通过制备两种不同结构的反渗透膜,从碳酸钙的成核热力学和与膜的黏附作用出发,考察膜表面特性和表面结构对碳酸钙结垢的影响.结果表明,大叶结构反渗透膜的结垢程度更高,但垢易脱附,其对膜通量衰减率仅为1.52%;小叶结构反渗透膜的结垢程度低,但垢不易脱落,其对膜通量衰减率达9.77%.本研究为反渗透膜碳酸钙结垢的控制机制提供了基本思路,并提出膜表观结构的设计作为减少碳酸钙结垢策略的潜力.

Leading to reduce the flux and operation life of membranes,Calcium carbonate scales was considered to be one of key issues urgently to be solved in reverse osmosis(RO)systems.In this paper,based on the perspective of the nucleation thermodynamics of calcium carbonate and the adhesion to the membrane,the effects of characteristics on membrane surface scales were studied by preparing RO membrane with different structures.The results showed that RO membranes with large leaf structure had a higher degree of scaling but were easy to desorb,hence,the flux attenuation rate was only 1.52%;in the meanwhile,RO membranes with small leaf structure had a lower degree of scaling but were hard to desorb,hence,the flux attenuation rate was 9.77%.In a word,this research provided a preliminary understanding with the control mechanism of calcium carbonate scaling in reverse osmosis systems and pointed out that the design of membrane apparent structure was a key measure for reducing calcium carbonate scales.