摘要
某石化公司MBR工艺中采用两种不同工艺制备的聚偏氟乙烯(PVDF)型超滤膜深度处理制备精对苯二甲酸所产生的石化废水(简称PTA废水)。一种膜采用非溶剂相分离法制备(NIPS-PVDF);另一种膜采用热致相分离法制备(TIPSPVDF)。在使用中发现,两种膜均受到膜污染,但NIPS-PVDF膜污染更严重。针对这种膜污染差异,该文对PVDF膜进行了结构表征分析,通过综合对比两种膜的结构和使用环境,分析了膜污染差异的原因。结果表明NIPS-PVDF中空纤维膜主要为β晶型,极性较强;而TIPS-PVDF主要为α晶型,不显极性。PTA废水中含有浓度较高的钴、锰等金属离子,容易被极性较强的NIPS-PVDF膜吸附,从而对后者造成膜污染。对PVDF的能谱分析(EDS)佐证了上述分析。该文最后给出了缓解膜污染的若干建议。
As UF membranes, tow types of PVDF were used to treat FFA wastewater in advanced treatment process in an oil and gas company. One was produced by non-solvent induced phase separation method, called NIPS - PVDF; the other was prepared by thermally induced phase separation method, called TIPS - PVDF. The two types of PVDF membranes were polluted and membrane fouling of NIPS - PVDF was much severer in use. In view of this difference in membrane fouling, structure characterizations of membranes were performed and analyzed to seek the mechanism behind by comparing the structural characters of two types of membranes and analyzing the wastewater composition. The results show that NIPS - PVDF is mainly formed by β crystal phase which has strong polarity, and TIPS - PVDF is mainly formed by α crystal phase which has no polarity. High concentration of Co ions and Mn ions in PTA wastewater have stronger tendency to be adsorbed by the polar NIPS - PVDF and thereafter cause severe membrane foiling. EDS analysis of PVDF membranes further affirms such analysis. Finally, a few suggestions of relieving membrane fouling were raised.
出处
《净水技术》
CAS
2015年第5期64-69,共6页
Water Purification Technology
关键词
石化废水
膜污染
MBR系统PVDF膜
petrochemical wastewater membrane fouling MBR system PVDF membrane
