AWWA MTC57553

Current and proposed regulations focus on increasingly stricter water quality goals with respect to microbial and turbidity removal, while also including challenges such as balancing microbial risk and minimization of disinfection byproducts (DBPs). Microfiltration (MF) and ultrafiltration (UF) are low-pressure membrane treatment processes that function by physically straining pathogens and other particulate matter, and do not require use of chemical oxidants to disinfect feed water. They are capable of providing effective removal of microbial and particulate contaminants. Thus, they have become extremely attractive technologies for meeting the challenges of current and proposed regulations. Effective contaminant removal using MF/UF processes assumes that the integrity of the membranes remains intact. Integrity monitoring is required to ensure high and consistent finished water quality. Thus, currently one of the most important issues in the practical application and proper regulatory acceptance of these processes involves the methods of monitoring the integrity of the membrane and the process. However, effects of membrane integrity on process performance and the various methods and tools available for integrity monitoring have not yet been analyzed in detail for different types of membrane systems, especially from results derived from full-scale testing and validation. Dilution effects of an integrity breach are different in pilot scale units versus full-scale membrane racks. Thus, full scale testing is required for proper and realistic evaluation of these methods. The work presented here is being performed as part of an ongoing AwwaRF research project on integrity testing of low-pressure membrane processes. The study includes testing of various integrity monitoring methods at full-scale at selected water treatment plants. The testing is being performed at six participant membrane plants representing different membrane systems. At the time of writing this manuscript, the testing at the fourth plant in the sequence has been completed. This paper presents interim results from the ongoing research project. Includes 4 references, table, figures.