【作者】 邱恒；

【导师】 汪永辉；

【作者基本信息】 东华大学 ， 环境工程， 2010， 硕士

【摘要】 本文以聚醚砜（PES）、聚丙烯腈（PAN）为膜材料、氯化锂和聚乙烯吡咯烷酮（PVP）为添加剂,由浸入沉淀相转化法制膜。初步探讨了不同PES、PAN和添加剂含量对膜强度、伸长率和制膜液粘度的影响。通过膜孔径、孔隙率、纯水通量、BSA截留率的测定,扫描电镜（SEM）的分析,研究制膜过程的主要因素对膜结构和性能的影响。根据正交实验结果分析,得到较佳的PES/PAN膜制备方案为:PES/PAN（质量比）为8:2,总质量分数为16%,添加剂为LiCl和PVP,LiCl/PVP（质量比）为2:8,总质量分数为8%。制得的PES/PAN共混膜在0.2MPa操作条件下,纯水通量为302.57L·m^-2·h^-1,比相同条件下不加PAN的PES膜高近1倍,BSA截留率为86.4%,变化不大。本实验用印染废水取自上海某旗蓬厂的实际废水,将PES/PAN共混膜用于膜生物反应器（MBR）中处理该印染废水。在正交实验的基础上,进一步探讨各个制膜因素对膜通量和MBR出水水质的影响,得到最佳制膜方案,使所制膜处理的MBR出水水质满足《城市污水再生利用城市杂用水水质标准》（GB/T 18920-2002）中最优标准的条件下,膜通量尽可能最大。PES/PAN共混膜的制膜方案为:PES/PAN（质量比）为8:2,总质量分数为15%,添加剂为LiCl和PVP,LiCl/PVP（质量比）为2:8,总质量分数为10%,铸膜液温度为40℃,蒸发时间为90s,凝固浴为质量分数5%的DMAc溶液,凝固浴温度为40℃,凝固浴中停留时间为5min。在0.2MPa操作条件下,上述条件所制PES/PAN膜的纯水通量为505.89 L·m^-2·h^-1,其纯水通量比自制PES膜高近1倍,比商品PES超滤膜高近2倍。PES/PAN膜对曝气池中废水COD_cr、浊度、色度的去除率分别为71.8%、80.6%、78.6%,略低于PES膜,基本保证出水水质达到回用标准的条件下能达到最大水通量,有实际应用价值。在25℃,90KPa操作条件下,在MBR中分别用PES/PAN共混膜、自制PES膜和商品PES膜连续运行24h,可知PES/PAN膜通量普遍比PES膜高,PES/PAN膜、自制PES膜和商品PES超滤膜单位时间内膜通量的变化分别为0.2559L·m^-2·h^-1·min^-1、0.3366L·m^-2·h^-1·min^-1、0.3539 L·m^-2·h^-1·min^-1,PES/PAN通量衰减速率最慢,抗污染性优于PES膜。三种膜在MBR中连续运行15d后,取出污染的膜,经过化学清洗后,PES/PAN膜、自制PES膜和商品PES超滤膜纯水通量恢复率分别为83.75%、63.58%、61.32%,PES/PAN膜通量恢复率最大,抗污染性优于PES膜。在MBR中连续运行24小时后,通过扫描电镜照片分析,PES膜比PES/PAN膜污染严重,PES/PAN膜的抗污染性能提高了,使用周期更长,有实际应用价值。更多还原

【Abstract】 In the paper,the blending membrane was prepared by immersion precipitation phase inverse method with polyethersulfone（PES） and polyacrylonitrile（PAN） as membrane materials,lithium chloride（LiCl） and polyvinylpyrrolidone（PVP） as additives.The effects of different contents of PES,PAN and additives on membrane strength,elongation and viscosity of membran ecasting solution were preliminarily discussed.By the determination of membrane poresize,porosity,pure water flux,BSA rejection rate and scanning electron microscope（SEM） analysis,the effects of serial main factors in the process of membrane preparation on the membrane structure and performance were studied.According to the analysis of the orthogonai experiment results,the optimum PES/PAN blending membrane preparation programs was:PES/PAN（mass ratio）was 8: 2,the total mass fraction was 16%,additives were LiCl and PVP,LiCl/PVP（mass ratio） was 2:8, the total mass fraction was 8%.when the press was 0.2MPa,the pure water flux of the PES/PAN membrane was 302.57L·m^-2·h^-1,which was nearly 1 time higher than the PES membrane prepared under the same condition,but BSA rejection rate was 86.4%with little change.In the experiment,the printing and dyeing wastewater was confected on the basic of the practical water quality of one banner and tent factory in ShangHai.The PES/PAN blending membrane was used to treat the printing and dyeing wastewater in a MBR.On the basic of the orthogonal experiment,the influence of membrane preparation factors on membrane flux and MBR effluent quality were further analyzed,then the optimal membrane preparation method was confirmed.When the MBR effluent quality treated by the membrane prepared by the best method meet the optimal standard of "water quality standards of regenerated and miscellaneous sewage for urban"（GB/T18920-2002）,the membrane flux should reach the maximum value as much as possible.Membrane preparation method of the PES/PAN blending membrane was:PES/PAN （mass ratio） was 8:2,the total mass fraction was 15%,additives were LiCl and PVP,LiCl/PVP （mass ratio） was 2:8,the total mass fraction was 10%,membrane casting solution temperature was 40℃,evaporation time was 90s,coagulation bath was solution including 5%DMAc, coagulation bath temperature was 40℃,residence time in coagulation bath was 5min.when the press was 0.2MPa,the pure water flux of the PES/PAN membrane prepared under the above conditions was 505.89 L·m^-2·h^-1,nearly 1 time higher than that of the self-made PES membrane, nearly 2 times higher than commercial PES membrane.The COD_cr,turbidity,chroma and ammonia nitrogen removal efficiency of wastewater in aeration tank were respectively 71.8%, 80.6%,78.6%,19.7%by PES/PAN membrane,slightly lower than PES membrane.When the quality of MBR effluent treated by the PES/PAN membrane meet the reuse standard,the membrane flux basically reach the maximum,the PES/PAN membrane had practical applying value.Under the operational condition of 25℃and 90KPa,the PES/PAN blending membrane, self-made PES membrane,commercial PES membrane were continuously used in a MBR for 24h,it was found that the PES/PAN membrane flux was generally higher than PES membrane, membrane flux variation in unit time of PES/PAN membrane,self-made PES membrane, commercial PES membrane were respectively 0.2559L·m^-2·h^-1·min^-1,0.3366L·m^-2·h^-1·min^-1, 0.3539L·m^-2·h^-1·min^-1,flux of PES/PAN membrane was decreased most slowly,the anti-fouling performance of PES/PAN membrane was better than that of PES membrane.After three kinds membranes were continuously ran in a MBR for 15d,polluted membranes were took out.After chemical cleaning for polluted membranes,PES/PAN membrane,self-made PES membrane, commercial PES membrane were respectively 83.75%,63.58%,61.32%,the pure water flux recovery rate of PES/PAN membrane was the maximum,the anti-fouling performance of PES/PAN membrane was better than that of PES membrane.After 24h in MBR,analyses with scanning electron microscopy（SEM） also indicated that PES membrane was polluted more serious than PES/PAN membrane,the antifouling performance of PES/PAN membrane improved,its utilization period was longer and PES/PAN membrane had practical applying value.更多还原