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Pesticides are used in agriculture to protect crops from pathogens, insects, fungi and weeds, but the release of pesticides into surface/groundwater by agriculture runoff and rain has raised serious concerns not only for the environment but also for human health. This study aimed to investigate the impact of surface properties on the performance of seven distinct membrane types utilized in nanofiltration (NF), reverse osmosis (RO) and forward osmosis (FO) processes in eliminating multiple pesticides from spiked water. Out of the membranes tested, two are self-fabricated RO membranes while the rest are commercially available membranes. Our results revealed that the self-fabricated RO membranes performed better than other commercial membranes (e.g., SW30XLE, NF270, Duracid and FO) in rejecting the targeted pesticides by achieving at least 99% rejections regardless of the size of pesticides and their log K ow value. Despite the marginally lower water flux exhibited by the self-fabricated membrane compared to the commercial BW30 membrane, its exceptional ability to reject both mono- and divalent salts renders it more apt for treating water sources containing not only pesticides but also various dissolved ions. The enhanced performance of the self-fabricated RO membrane is mainly attributed to the presence of a hydrophilic interlayer (between the polyamide layer and substrate) and the incorporation of hydrophilic nanosheets in tuning its surface characteristics. The findings of the work provide insight into the importance of membrane surface modification for the application of not only the desalination process but also for the removal of contaminants of emerging concern. [Display omitted] • Membrane rejection against pesticides varied depending on its physiochemical properties. • RO membranes showed the highest pesticides rejection followed by NF and FO membranes. • Improving surface properties of RO membranes using GO further enhanced pesticides removal. • GO-modified RO membrane achieved >99% rejections regardless of pesticide size and log K ow. [ABSTRACT FROM AUTHOR]

Research on the effect of interfacial polymerization (IP) temperature during polyamide layer synthesis is lacking, especially for thin film nanocomposite (TFN) nanofiltration membrane. Typically, polyamide composite membranes are fabricated at room temperature, ignoring the potential impact of reaction temperature. In this work, we varied the organic solvent temperature to study its impacts on the properties of TFN membrane containing surface-functionalized graphene oxide (GO) for nanofiltration process. A more cross-linked and rougher polyamide layer could be formed at 55 °C due to higher reaction kinetics and more volatile IP reaction. This membrane exhibited excellent Na 2 SO 4 rejection (99 %) with a water-salt permselectivity ratio of 11.0, i.e., >2 folds compared to the commercial membrane (4.88). However, its rougher surface resulted in a higher protein adhesion even with the enhanced antifouling property brought by GO hydrophilicity. In comparison, the TFN membrane developed at 0 °C displayed very thin yet smooth polyamide layer, resulting in a higher water flux and improved antifouling performance. Furthermore, the TFN membrane demonstrated stable filtration performance for 12 h and GO nanosheets were still well accommodated within selective layer after testing. Overall, the improved filtration performance and reduced protein adsorption demonstrated the feasibility of IP temperature variation in TFN membrane fabrication. [Display omitted] • Temperature plays an important role during TFC/TFN membrane fabrication. • GO was functionalized to improve its hydrophilicity and dispersibility in solvent. • Higher IP temperature could increase water-salt permselectivity ratio of membrane. • Low IP temperature meanwhile improved membrane water flux and fouling resistance. [ABSTRACT FROM AUTHOR]

Membrane is often aimed to achieve high rejection rates against salts and dyes in order to produce high quality permeate. However, large amount of salts presents in textile wastewater could be recovered and reused for dyeing process. In this work, we fabricated new thin film nanocomposite (TFN) membrane with improved surface properties using emerging mist-based interfacial polymerization technique in an attempt to recover salts from salt/dye solution. Prior to membrane fabrication, graphene oxide (GO) was surface-functionalized using greener approach to improve its dispersion in solution for better distribution within membrane selective layer. Compared to control GO, acrylic acid (AA)-modified GO was able to improve pure water permeability (PWP) of TFN membrane by 6.6%, reaching 11.34 L/m2·h·bar. Its PWP was also higher compared to thin film composite membrane (~25% enhancement) owing to enhanced membrane hydrophilicity coupled with formation of thin yet highly crosslinked PA upon modified GO incorporation. When tested using salt/dye mixture, the best TFN membrane could recover 79–86% of NaCl from the feed, producing saline permeate containing <0.3% pigment. The high NaCl recovery achieved by the TFN membrane coupled with excellent dye rejection offers a solution for potential reuse of saline permeate for dyeing process. [Display omitted] • Greener synthesis approaches were adopted to develop TFN membrane for NF process. • The best TFN membrane showed 25% higher water flux compared to TFC membrane. • The TFN membrane was able to achieve >99.2% rejection against dyes tested. • It also has the potential to recover NaCl from dye/salt mixture for reuse purpose. [ABSTRACT FROM AUTHOR]