为了了解次氯酸钠清洗对聚偏氟乙烯（PVDF）膜性能的损伤情况，借助正交试验和层次分析模型分析评价了清洗条件对PVDF膜性能的影响，并对清洗过程中PVDF膜面变红的现象进行了探讨．正交试验选择了清洗浓度、清洗时间和pH值3个清洗条件．结果表明，次氯酸钠的pH值对PVDF膜的平均孔径和比通量影响最大，清洗时间对接触角的影响最大，而次氯酸钠浓度对洗脱液的总有机碳（TOC）影响最大．借助层次分析模型获得了正交试验范围内对PVDF膜性能损伤最小的清洗条件为：清洗浓度0.1%，清洗时间25 h和pH值9．次氯酸钠清洗过程中，PVDF膜面颜色变红只与pH值有关，而与次氯酸钠浓度无关，这主要是由于高的pH值会造成制孔剂聚乙烯吡咯烷酮（PVP）的溶解和PVDF结构的变化．
 

Abstract：In order to further understand the membrane damage induced by the sodium hypochlorite cleaning, the orthogonal experiment and analytic hierarchy model were applied for investigating the influences of cleaning conditions on the perforamnce of PVDF microfiltration membranes commonly used in the membrane bioreactors. In the orthogonal experiment, the concentration of sodium hypochlorite, cleaning time and pH value were selected as the cleaning conditions, and the results indicated that the pH value had more significant impcats on the mean pore size and flux ratio of the PVDF membranes compared to other cleaning conditions. Furthermore, cleaning time and sodium hypochlorite concentrations significantly influenced the contact angle and TOC in the eluent, respectively. According to the method of analytic hierarchy process, the optimized cleaning conditions with the minimum damage on the performance of PVDF membranes were sodium hypochlorite concentration of 0.1 %, cleaning time of 25 h and pH value of 9. It should be pointed out that the PVDF membranes became red during the sodium hypochlorite cleaning when the pH value reached 12.7, which might be attributed to the dissolution of PVP and the variation of PVDF structure due to the high pH value. The results also indicated that this phenomenon was only due to pH value and did not have any relations with the sodium hypochlorite concentration.
 

[1]张迎敏, 吴佩琳, 孙娜, 等. 混凝剂对化学强化MBR深度处理印染废水的影响[J]. 膜科学与技术, 2013, 33(4): 82–87.
[2]肖小兰, 陈康, 王新华, 等. 钙离子胁迫下SRT对MBR中污泥性质及膜污染的影响[J]. 膜科学与技术, 2010, 32(4): 112–117.
[3]傅 威, 王志伟, 尹 星, 等. 膜生物反应器长期运行条件下膜的清洗方法及机理研究[J]. 中国给水排水, 2009, 35: 177–183.
[4]Le-Clech P, Chen V, Fane T A G. Fouling in membrane bioreactors used in wastewater treatment[J]. Journal of Membrane Science, 2006, 284(1–2): 17–53.
[5]Wang P, Wang Z W, Wu Z C, et al. Effect of hypochlorite cleaning on the physiochemical characteristics of polyvinylidene fluoride membranes[J]. Chemical Engineering Journal, 2010, 162(3): 1050–1056.
[6]Abdullah S Z, Berube P R. Assessing the effects of sodium hypochlorite exposure on the characteristics of PVDF based membranes[J]. Water Research, 2013, 47(14): 5392–5399.
[7]胡保安. 聚偏氟乙烯中空纤维污染膜的清洗研究[D]: [学位论文]. 天津: 天津工业大学, 2004.
[8]谢元华, 朱彤, 徐成海, 等. 金属膜生物反应器中膜污染清洗方法[J]. 化学工程, 2010, 10: 190-193.
[9]徐飞, 李桂水. 聚醚砜膜原位清洗方法的实验研究[J]. 过滤与分离, 2007, 01: 19-21.
[10]姜海凤. PVDF及其杂化膜的制备与表征[D]: [学位论文]. 山东: 中国海洋大学, 2009.
[11]陆茵. PVDF相转化成膜机理及制膜规律研究[D]: [学位论文]. 浙江: 浙江大学, 2003.
[12]郑少华, 姜奉华. 试验设计与数据处理[M]. 北京: 中国建材工业出版社, 2004.
[13]Shima H, Alice A, Greg L, et al. Relative impact of fouling and cleaning on PVDF membrane hydraulic performances[J]. Separation and purification technology, 2012, 90: 204–212.
[14]Philip J E, Michael R B, Arto P, et al. The influence of hydrophobicity, roughness and charge upon ultrafiltration membranes for black tea liquor clarification[J]. Journal of Membrane Science, 2008, 313(1-2): 250-262.
[15]王新华, 吴志超, 华娟, 等. 平板膜污泥浓缩工艺操作条件的优化研究[J]. 环境污染与防治, 2008, 30(6): 54–57.
[16]韦鹤平. 环境系统工程[M]. 上海: 同济大学出版社, 1993.
[17]Hashim N A, Liu Y T, Li K. Stability of PVDF hollow fibre membranes in sodium hydroxide aqueous solution[J]. Chemical Engineering Science, 2011, 66(8): 1565–1575.
[18]Puspitasari V, Granville A, Le-Clech P, et al. Cleaning and ageing effect of sodium hypochlorite on polyvinylidene fluoride (PVDF) membrane[J]. Separation and Purification Technology, 2010, 72(3): 301–308.
[19]Zhang S C, Shen J, Qiu X P, et al. ESR and vibrational spectroscopy study on poly(vinylidene fluoride) membranes with alkaline treatment[J]. Journal of Power Sources, 2006, 153(2): 234–238.
[20]Komaki Y, Otsu H. Observation of nuclear track development in polyvinylidene fluoride with several etchants[J]. Journal of Electron Microscopy, 1981, 30(4): 292–297.