Nanocomposite Polymeric Membranes for Organic Micropollutant Removal: A Critical Review

Abstract

The prevalence of organic micropollutants (OMPs) and their persistence in water supplies have raised serious concerns for drinking water safety and public health. Conventional water treatment technologies, including adsorption and biological treatment, are known to be insufficient in treating OMPs and have demonstrated poor selectivity toward a wide range of OMPs. Pressure-driven membrane filtration has the potential to remove many OMPs detected in water with high selectivity as a membrane's molecular weight cutoff (MWCO), surface charge, and hydrophilicity can be easily tailored to a targeted OMP's size, charge and octanol−water partition coefficient (K ow ). Over the past 10 years, polymeric (nano)composite microfiltration (MF), ultrafiltration (UF), and nanofiltration (NF) membranes have been extensively synthesized and studied for their ability to remove OMPs. This review discusses the fate and transport of emerging OMPs in water, an assessment of conventional membrane-based technologies (NF, reverse osmosis (RO), forward osmosis (FO), membrane distillation (MD) and UF membrane-based hybrid processes) for their removal, and a comparison to the state-of-the-art nanoenabled membranes with enhanced selectivity toward specific OMPs in water. Nanoenabled membranes for OMP treatment are further discussed with respect to their permeabilities, enhanced properties, limitations, and future improvements.

Nanofibrous Membranes from Catalytic Arene–Norbornene Annulation (CANAL)-Based Polymers for Scavenging Organic Micropollutants

“…Various methods have been used for water treatment and OMP removal, including adsorption, membrane separation, , photoelectrocatalysis, and biological treatments . Among these, adsorption is the best method for water treatment owing to its low cost, simple operation, and eco-friendliness .…”

Boosting the Performance of Nanofiltration Membranes in Removing Organic Micropollutants: Trade-Off Effect, Strategy Evaluation, and Prospective Development

“…Driven by the demand of cost-efficient OMP removal, increasing studies have been conducted on the optimization of conventional polyamide (PA) TFC membranes as well as the development of novel membranes. − However, due to the large variety and distinct properties of OMPs, the assessment and enhancement of membrane performance in terms of OMP removal could be more complicated than that for salt rejection in desalination. To date, several review papers have been devoted to the removal of OMPs by membranes, mainly focusing on the OMP rejection mechanisms, the effects of operational conditions, or the applicability of different membrane-based treatment processes. − A few efforts were recently made from the perspective of membrane synthesis, which discussed various strategies to tailor membrane chemistry and structure for enhanced removal of OMPs. , However, comparative analysis on the performance of these newly developed membranes has not be conducted, not to mention using the insightful trade-off relationship as the criterion. This research gap inevitably hinders the obtainment of knowledge to guide the rational design and synthesis of membranes of better performance in terms of OMP removal.…”

Direct Contact Membrane Distillation for Treatment of Mixed Wastewater of Humic Acid and Reactive Dye: Membrane Flux Decline and Fouling Analysis

“…Moreover, development of material technology on nanocomposite polymeric membranes has been reported to achieve a higher organic removal and membrane permeate flux through surface modification. Common procedures to modify membrane surfaces include nanoparticle coating and deposition, chemical bonding, and grafting methods. , …”

“…Common procedures to modify membrane surfaces include nanoparticle coating and deposition, chemical bonding, and grafting methods. 8,9 Membrane distillation has been tested and researched in different fields such as desalination, food production, brine concentration, and others. Nevertheless, fouling deposition is one of the major problems for the application of membrane distillation.…”

“…Common procedures to modify membrane surfaces include nanoparticle coating and deposition, chemical bonding, and grafting methods. 8 , 9 …”