PVDF疏水膜的制备及其在苦咸水脱盐中的应用  

Fabrication of Hydrophobic PVDF Hollow Fiber Membranes for Desalination of Brackish Water through Membrane Distillation

作　　者：侯得印[1] 王军[1] 王宝强[2] 孙项城[1] 栾兆坤[1] 任晓晶[1] 

机构地区：[1]中国科学院生态环境研究中心环境水质学国家重点实验室,北京100085 [2]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《北京大学学报（自然科学版）》2010年第3期395-400,共6页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：“十一五”国家科技支撑计划专题(2006BAJ08B05,2006BADO1B02-02)资助

摘　　要：采用相转化法以无机盐氯化锂(LiCl)和水溶性聚合物聚乙二醇(PEG)为添加剂,制备了聚偏氟乙烯(PVDF)中空纤维疏水膜,所制得的膜具有较高的盐截留率,膜通量可达40.5kg/(m2.h)。以自制的PVDF疏水膜进行了直接接触式膜蒸馏(DCMD)苦咸水脱盐应用试验研究。实际苦咸水淡化过程中,随着浓缩倍率的提高在进料侧会产生CaCO3沉淀造成膜组件堵塞、疏水膜受到污染,致使膜渗透通量下降、产水电导率升高。酸化预处理可以消除沉淀物对膜蒸馏过程的影响,酸化后整个膜蒸馏过程中膜渗透通量保持稳定,产水水质良好,其电导率不超过10μS/cm。The mixture of inorganic sah LiCl and soluble polymer polyethylene glycol （PEG） as non-solvent additive was introduced to fabricate hydrophobic polyvinylidene fluoride （PVDF） hollow fiber membrane by phase inversion process. The membrane exhibited high rejection of inorganic salt solutes and a maximum permeate flux 40.5 kg/（m^2·h） was obtained. During direct contact membrane distillation （DCMD） process, the precipitation of CaCO3 would he formed and clog the hollow fiber inlets with gradual concentration of the feed when natural brackish water was used directly as feed solution, which resulted in a rapid decline of membrane module efficiency. The negative influence of scale deposits could he eliminated by acidification of the feed. The DCMD desalination experiment of acidified brackish water showes that the PVDF membrane had stable permeate flux and the conductivity of the obtained distillate remained below 10μS/cm during the whole process.

关 键 词：聚偏氟乙烯 膜通量 膜蒸馏 苦咸水 膜污染 

分 类 号：X52[环境科学与工程—环境工程]