Impact of sodium hypochlorite on rejection of non-steroidal anti-inflammatory drugs by biomimetic forward osmosis membranes

Degradation of polyamide nanofiltration membranes by free chlorine and halide ions: Kinetics, mechanisms, and implications

The kinetics of polyamide membrane degradation by free chlorine and halide ions (Br- and Cl-) were innovatively evaluated based on physicochemical properties and filtration performance, using water/solute permeability coefficient in addition to bromide incorporation as important indicators. The reaction rate constants for the reduced water and H3BO3 permeability coefficient were 1-2 orders of magnitude higher at 0-1 h than 1-10 h. N-bromination and bromination-promoted hydrolysis are dominant degradation mechanisms at 0-1 h (reflected by the breakage of hydrogen bond, the increased Ca binding content, and the increased charge density), and ring-bromination further occurs at 1-10 h (reflected by the disappearance or weakening of aromatic amide band and the nearly constant hydrogen bond). The more reactive but less abundant brominating agents (Br2O, BrOCl, BrCl, and Br2) played significant roles in membrane degradation, contradicting the conventional belief that HOBr is the only reactive species. BrCl at pH 4.0 and BrOCl and Br2O at pH 7.0 made significantly higher contributions to membrane degradation than HOBr (>76 % vs. <13 %). The increased contribution of BrCl and Br2 with the increased [Cl-] and [Br-]ex (the excess bromide, defined as [Br-]o - [HOCl]o when [Br-]o > [HOCl]o), respectively, was responsible for the greater reduction of water permeability coefficient. The innovative and simple approach developed in this study provides important insights to evaluate and predict membrane degradation.

Recent advances in surface tailoring of thin film forward osmosis membranes: A review

The recent advancements in fabricating forward osmosis (FO) membranes have shown promising results in desalination and water treatment. Different methods have been applied to improve FO performance, such as using mixed or new draw solutions, enhancing the recovery of draw solutions, membrane modification, and developing FO-hybrid systems. However, reliable methods to address the current issues, including reverse salt flux, fouling, and antibacterial activities, are still in progress. In recent decades, surface modification has been applied to different membrane processes, including FO membranes. Introducing nanochannels, bioparticles, new monomers, and hydrophilic-based materials to the surface layer of FO membranes has significantly impacted their performance and efficiency and resulted in better control over fouling and concentration polarization (CP) in these membranes. This review critically investigates the recent developments in FO membrane processes and fabrication techniques for FO surface-layer modification. In addition, this study focuses on the latest materials and structures used for the surface modification of FO membranes. Finally, the current challenges, gaps, and suggestions for future studies in this field have been discussed in detail.

Non-steroidal anti-inflammatory drugs (NSAIDs) in the environment: Recent updates on the occurrence, fate, hazards and removal technologies

Non-steroidal Anti-inflammatory Drugs (NSAIDs) are extensively utilized pharmaceuticals worldwide. However, owing to the improper discharge and disposal practices, they have emerged as significant contaminants that are widely distributed in water, soils, and sewage sediments. This ubiquity poses a substantial threat to the ecosystem and human health. Consequently, it is imperative to develop rapid, cost-effective, efficient and reliable approaches for containing these substance in order to mitigate the deleterious impact of NSAIDs. This research provides a comprehensive review of the occurrence, fate, and hazards associated with NSAIDs in the general environment. Additionally, various removal technologies, including advanced oxidation processes, biodegradation, and adsorption, were systematically summarized. The study also presents a comparative analysis of the benefits and drawbacks of different removal technologies while interpreting challenges related to NSAIDs' removal and proposing strategies for future development.

Membrane technology for pesticide removal from aquatic environment: Status quo and way forward

The noxious side effects of pesticides on human health and environment have prompted the search of effective and reliable treatment techniques for pesticide removal. The removal of pesticides can be accomplished through physical, chemical and biologicals. Physical approaches such as filtration and adsorption are prevailing pesticide removal strategies on account of their effectiveness and ease of operation. Membrane-based filtration technology has been recognized as a promising water and wastewater treatment approach that can be used for a wide range of organic micropollutants including pesticides. Nanofiltration (NF), reverse osmosis (RO) and forward osmosis (FO) have been increasingly explored for pesticide removal from aquatic environment owing to their versatility and high treatment efficiencies. This review looks into the remedial strategies of pesticides from aqueous environment using membrane-based processes. The potentials and applications of three prevailing membrane processes, namely NF, RO and FO for the treatment of pesticide-containing wastewater are discussed in terms of the development of advanced membranes, separation mechanisms and system design. The challenges in regards to the practical implementation of membrane-based processes for pesticide remediation are identified. The corresponding research directions and way forward are highlighted. An in depth understanding of the pesticide nature, water chemistry and the pesticide-membrane interactions is the key to achieving high pesticide removal efficiency. The integration of membrane technology and conventional removal technologies represents a new dimension and the future direction for the treatment of wastewater containing recalcitrant pesticides.

Membrane Fouling Behavior of Forward Osmosis for Fruit Juice Concentration

Forward osmosis (FO) technology has a broad application prospect in the field of liquid food concentration because of the complete retention of flavor components and bioactive substances. Membrane fouling is the main obstacle affecting the FO performance and concentration efficiency. This work systematically investigated the membrane fouling behavior of the FO process for fruit juice concentration elucidated by the models of resistance-in-series, xDLVO theory and FTIR analysis. The results show that the AL-FS mode was more suitable for concentrating orange juice. Increasing the cross-flow rate and pretreatment of feed solutions can effectively improve the water flux and reduce the fouling resistance. The ATR-FTIR analysis revealed that the fouling layer of orange juice was mainly composed of proteins and polysaccharides, and the pretreatment of microfiltration can greatly reduce the content of the major foulant. There was an attractive interaction between the FO membrane and orange juice foulants; by eliminating those foulants, the microfiltration pretreatment then weakened such an attractive interaction and effectively prevented the fouling layer from growing, leading to a lower process resistance and, finally, resulting in a great improvement of concentration efficiency.