超声技术结合小波分析在线监测中空纤维膜污染及其可视化研究  

In-situ visualization of hollow fiber membrane fouling by ultrasonic-based wavelet technique

作　　者：李建新[1] 许新成[1] 徐妮妮[2] 张玉忠[1] 

机构地区：[1]天津工业大学材料科学与工程学院教育部中空纤维膜材料与膜过程重点实验室,天津300160 [2]天津工业大学信息与通信工程学院,天津300160

出　　处：《膜科学与技术》2010年第2期1-7,共7页Membrane Science and Technology

基　　金：国家自然科学基金资助项目(20676100和20876115);教育部新世纪优秀人才支持计划(NCET-06-0250);天津市应用基础及前沿技术研究计划(08JCZDJC24000)

摘　　要：采用超声时域反射法和小波分析技术在线监测单根内压式聚醚砜中空纤维微滤膜(ID/OD为0.8 mm/1.2 mm)处理2.4 g/L高岭土污水时的初期污染情况.结果显示:小波谱图能够提供中空纤维膜内部结构和污染过程的清晰2D和3D图片,实现了膜污染在线监测过程的可视化.随着污染的进行,膜通量不断下降,小波谱图上中空纤维膜断面上部和下部的信号持续时间在时间区域内发生了有序移动.小波谱图的这种有序变化与污染物在膜表面的沉积以及污染层的生长有关.SEM观察显示,污染420 min后中空纤维膜内腔下表面形成的污染层比内腔上表面的污染层厚.这与通过小波谱图信号持续时间变化计算得出的污染层厚结果一致.Ultrasonic time- domain reflectometry （UTDR） and wavelet transform were employed to monitor the initial fouling in a single polyethersulfone hollow fiber membrane （inside diameter： 0.8 mm; outside diameter： 1.2 mm） during microfiltration of 2.4 g/L kaolin solution. Results showed that the hollow fiber structure and membrane fouling were visualized from the wavelet contour map. The membrane flux declined with the fouling process, whereas the echo durations of upside and underside walls of the hollow fiber lumen changed regularly in timedomain with the fouling process. These systematic changes are relevant to the surface deposition and growth of fouling layer on the fiber lumen. At 420 min of fouling operation, SEM observation revealed that the fouling layer deposited on the underside surface of the lumen was thicker than that on the upside surface, which corresponded well with the results obtained by ultrasonic measurements.

关 键 词：中空纤维膜 膜污染 超声时域反射法 小波变换 实时在线监测 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]