Development and performance characterization of first-generation dendrimeric nanofiltration membranes

Upstream processes used for oil and gas production generate brackish water as a byproduct called produced water. Desalination and reuse of produced water can potentially be a new resource for freshwater which may alleviate local and global water scarcity. Currently, reverse osmosis (RO) is the state-of-the-art technology for desalination of brackish water; however, RO treatment of relatively high salinity produced water is prohibitive or not feasible because in addition to treating toxic organic solutes they provide high rejection of background electrolytes. Consequently there is a need to develop nanofiltration (NF) membrane filtration processes effective in removing dissolved organic matter while allowing passage of inorganic salts. In this project, seven distinct novel first generation (G1) NF polyamide membranes have been developed and studied to understand their rejecting capability against selected organic surrogate, Rhodamine-WT (R-WT), and inorganic salts, NaCl and MgSO4. All seven membranes resulted in a similar and high rejection of R-WT at around 96% or above, and a spectrum of varying rejections for NaCl ranging from 10% to 90%, and similar rejection for MgSO4. Rutherford back-scattering spectroscopy (RBS) analyses of G1 membranes revealed that their active layers had thickness in the range of 17-44 nm, all thinner compared to the range of 50-200 nm for commercial NF polyamide membranes.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste