粘胶纤维行业碱回收工艺中纳滤膜的清洗研究

Nanofiltration membrane fouling cleaning in alkali recovery of viscose fiber industry

粘胶纤维生产过程中产生含油溶解性半纤维素的浓碱液,应用耐碱纳滤膜过滤技术,实现NaOH与半纤维素分离,可达到回收碱液的目的.本项目工艺选用型号Suntar-357卷式复合耐碱膜,其正常运行通量为23L/(m^2·h),经过长期运行膜污染后,通量下降>60%.将膜芯剖开,通过酸碱溶解实验、丁达尔实验分析污染物为胶体类物质.选用LC-01、LC-90、LC-42清洗剂进行清洗,其中LC-42清洗剂效果最佳,其膜通量恢复率分别为52.2%、60.9%、73%及90.4%.经过逐步清洗,膜过滤通量恢复率为90%.

Concentrated alkali was generated during viscose fiber industry.Nanofiltration membrane was used to separate NaOH and semi cellulose.Suntar-357 nanofiltration membrane was applied in this project.The normal membrane flux was 23L/（m2·h）.After a long-term operation,the flux delined more than 60%.The fouling substances were identified as colloidal substances by alkali and acid dissolution experiment as well as Dindar experiment.LC-01,LC-90 and LC-42 were used as the cleaning agent.The LC-42 agent was the best.The water flux recovery was 52.2%,60.9%,73%,90.4%,respectively.The water flux recovery was 90% after cleaning step by step.