Acoustic sensor: a novel technique for low pressure membrane integrity monitoring

Control of membrane integrity is critical to assuring process efficacy in terms of microbial removal. Various monitoring techniques such as turbidity, particle counting, and air testing are commonly used in membrane operation. However, membrane integrity is not necessarily reflected by a changing of the permeate quality, i.e., turbidity as well as particle count. Therefore, acoustic integrity monitoring (AIM) was developed to monitor the integrity of the membrane, especially when other techniques such as particle counting are not applicable. Based on hydrophon ic sensor technology, the acoustic monitoring technique consists of measuring the noise due to a compromised fiber. The advantage of a hydrophonic sensor is that integrity of the membranes is monitored continuously during filtration. Moreover, AIM enables detection of a non-cut compromised fiber with a hole of 0.5 mm which therefore guarantee- s more than 6 log removal of viruses.