Membrane technologies offer great promise to meet increasingly stringent regulatory requirements for potable water production. While other technologies can achieve similar treatment objectives, membranes offer notable advantages. For example, microfiltration (MF) and ultrafiltration (UF) membranes may or can be configured to provide high levels of pathogen removal without dependence on chemical pretreatment and provide a smaller pore size absolute barrier, in contrast to media filtration which relies on chemical pretreatment for adequate pathogen removal.
Other techniques such as nanofiltration (NF) and reverse osmosis (RO) membranes have made alternative water reclamation (i.e., brackish water and seawater) and wastewater reuse possible solutions to address the growing global scarcity of traditional water sources. Implementation of NF and RO processes in treating traditional water sources can provide a steady-state level of removal that eliminates the need for regeneration of ion exchange resins or granular activated carbon. RO can help meet future potable water demands through desalination of seawater and brackish waters. Although NF and RO membranes are generally not intended for disinfection, they provide an additional barrier for virus and bacteria removal, which is essential for indirect potable, wastewater reuse.
The focus of this research is biofouling prevention. Biofouling is the accumulation of microorganisms onto the membrane surface and on the feed spacer as present between the envelopes. Most of the research and development in the area of biofouling prevention has focused on pretreatment of the feed water, improved cleaning solutions, cleaning procedures, and fouling resistant membranes. The goal of this project is to modify the feed spacers used by reverse osmosis spiral wound elements with silver or copper ions as biocidal coatings. Conventionally, these ions have been added into the water electrolytically or as metal salts to disinfect water against microbial biofilms.
