Characterization and performance of a commercial thin film nanocomposite seawater reverse osmosis membrane and comparison with a thin film composite

The properties and performance of a recently developed thin film nanocomposite (TFN), with inorganic nanoparticles incorporated in the active layer, and standard thin film composite (TFC) spiral wound seawater desalination reverse osmosis (RO) membranes were assessed by comparison on the scale of 4040 and 8040 membrane modules. Scanning electron microscopy with energy-dispersive X-ray spectroscopy, contact angle-, and ζ-potential measurements did not show large differences between TFN membranes and a TFC membrane (SW30HRLE). Small scale pilot tests (4040 elements) showed that the TFN had a factor to higher water permeability as the TFC. Salt rejection was similar, but the TFC showed slightly better rejection of NDMA and glycerol. Larger scale pilot tests (multiple 8040 elements) confirmed the nearly twofold higher water permeability for the TFN as compared to aged TFC membranes (SW30XHR). However, the boron rejection of the TFN was lower than that of the aged TFC. Furthermore, an indirect comparison showed that the flux for the virgin TFN would be about 1.4 times that for the virgin TFC.