(514b) N-Nitrosodimethylamine (NDMA) Removal By Thin Film Composite Polyamide Reverse Osmosis Membranes

Water reuse and desalination are the most feasible ways to alleviate water scarcity in an increasingly drier planet. Although thin film composite polyamide (PA) membranes are capable of high ion rejection (above 99%), removal of small neutral molecules, such as disinfection byproducts (DBPs), is still challenging. DBPs (e.g., N-nitrosodimethylamine, NDMA), formed during water treatment, are insufficiently retained by commercial nanofiltration (NF) and reverse osmosis (RO) PA membranes, prepared by interfacial polymerization. In this paper, we explore NDMA removal by TFC membranes prepared via molecular layer-by-layer (mLbL) deposition. The mLbL approach enables the formation of a PA layer whose chemistry can be controlled at the single monomer level, thereby facilitating fundamental relations linking polymer chemistry to membrane morphological and transport properties.