UTDR Based Diagnosis for Membrane Filtration

Current techniques available for the characterization of membrane are destructive, including scanning electron microscopy, mercury intrusion porosimetry and size exclusion of particles. An alterative technique based on ultrasonic frequency domain reflectometry (UTDR) that allows easy, non-invasive and real-time analysis of membrane morphology would be of significant value to the membrane industry. This study presents the technical detection results using UTDR, which is capable of diagnosing membrane fouling on various operation conditions. The detection technique is the combination of the wavelet transforms (WT) and the decision tree (DT). WT is used to represent all the possible types of transients in generated vibration signals. It is used for feature extraction and their relative effectiveness in feature extraction is compared. DT has been used for feature selection as well as for classification. Experimental results show that the algorithms are indeed efficient and effective. Index Terms — Decision tree; Membrane fouling; Ultrafiltration; Wavelet analysis