PVDF-pDOPA复合膜应用于MBfR稳定性研究

Stability Study of PVDF-pDOPA Composite Membrane for MBfR

针对膜生物膜反应器(MBf R)中研究中疏水性微孔膜存在的生物亲和性差,氧传质能力不足等问题,采用自聚合法以左旋多巴为单体对自制疏水性聚偏氟乙烯(PVDF)中空纤维膜进行表面改性,制备适用于MBf R技术的新型疏水性中空纤维复合膜(PVDF-pDOPA复合膜),结果表明,复合膜氧总转移系数KLa由0.95×10^(-2) min^(-1)提升到1.61×10^(-2)min^(-1),接触角由75°下降到42°,复合膜的氧传质性能、亲水性能得到显著改善。复合膜经超声后仍然具有很好的亲水特性;分别超声10、20和30 min时,极限气体通量是原膜的约2倍;KLa分别衰减了4.89%、9.76%和12.20%,但KLa仍为原膜的1.64、1.55、1.51倍,其氧传质性能仍优于原膜,表明PVDF-pDOPA复合膜具有良好的稳定性。

Aimed at the insufficient oxygen supply capacity and bioaffinity property of hydrophobic microporous membrane in membrane biofilm reactor(MBfR), hydrophobic PVDF hollow fiber membrane was modified by self-polymerization using L-DOPA as monomer to prepare a new hydrophobic hollow fiber composite membrane(PVDF/p DOPA composite membrane) suitable for MBf R technology. The results showed that, the total oxygen transfer coefficient(KLa) of composite membrane was improved from 0. 95×10-2 min-1 to 1.61×10-2 min-1 and the contact angle decreased from 75° to 42°. The oxygen mass transfer performance and hydrophilicity of composite membrane were significantly improved. The composite membranes still had good hydrophilicity after ultrasonic treatment, when the ultrasonic time was 10, 20 and 30 min, the limiting gas flux was about 2 times of the original membrane.KLa decreased by 4.89%, 9.76% and 12.20%, respectively, but the KLa of the composite membranes remained 1.64, 1.55, 1.51 times of the original membrane, its oxygen mass transfer performance was still better than that of the original membrane, It indicated that PVDF/pDOPA composite membrane had good stability.