Ultrasonic waves for characterisation of clay membranes Original Research Article

Clay membranes containing various percentages of coal before sintering have been manufactured in order to obtain various volume fractions of porosity. The present work concerns the characterization of new sintered clay microfiltration membranes. The results of the tests of filtration of water rich in dissolved organic matter and in suspension have turned out to be important for directing the clay membranes to the treatment of waters. Four membranes of different porosity were elaborated and tested. The quality control of the membranes was carried out by ultrasonic waves. Using echographic techniques, the ultrasonic velocity has been measured vs. porosity. Results have been obtained from 0 to 60% of porosity characterization after manufacturing, corresponding up to 20% of coal. The anomalous behaviour of one batch of membranes has been detected with ultrasonic waves and confirmed using classical porosity measurements (triple weight method). The ultrasonic technique can be used as a powerful tool to detect default of porosity of a clay membrane after manufacturing.