Designing sustainable membrane-based water treatment via fouling control through membrane interface engineering and process developments

Advancements in nanoparticle-modified zeolites for sustainable water treatment: An interdisciplinary review

The contamination of water sources with heavy metals, dyes, and other pollutants poses significant challenges to environmental sustainability and public health. Traditional water treatment methods often exhibit limitations in effectively addressing these complex contaminants. In response, recent developments in nanotechnology have catalyzed the exploration of novel materials for water remediation, with nanoparticle-doped zeolites emerging as a promising solution. This comprehensive review synthesizes current literature on the integration of nanoparticles into zeolite frameworks for enhanced contaminant removal in water treatment applications. We delve into synthesis methodologies, elucidate mechanistic insights, and evaluate the efficacy of nanoparticle-doped zeolites in targeting specific pollutants, while also assessing considerations of material stability and environmental impact. The review underscores the superior adsorptive and catalytic properties of nanoparticle-doped zeolites, owing to their high surface area, tailored porosity, and enhanced ion-exchange capabilities. Furthermore, we highlight recent advancements in heavy metal and organic pollutant uptake facilitated by these materials. Additionally, we explore the catalytic degradation of contaminants through advanced oxidation processes, demonstrating the multifunctionality of nanoparticle-doped zeolites in water treatment. By providing a comprehensive analysis of existing research, this review aims to guide future developments in the field, promoting the sustainable utilization of nanoparticle-doped zeolites as efficient and versatile materials for water remediation endeavors.

Improving antifouling performance of FO membrane by surface immobilization of silver nanoparticles based on a tannic acid: diethylenetriamine precursor layer for municipal wastewater treatment

In this study, a facile method for multifunctional surface modification on forward osmosis (FO) membrane was constructed by surface immobilization of AgNPs based on tannic acid (TA)/diethylenetriamine (DETA) precursor layer. The cellulose triacetate (CTA) FO membranes modified by TA and DETA with different co-deposition time (6 h, 12 h, 24 h) were investigated. Results indicated that the TA/DETA (24)-Ag CTA membrane with a TA/DETA co-deposition time of 24 h was identified to be optimal, which attained more hydrophilic. And it had the bacterial mortality of Escherichia coli and Staphylococcus aureus reaching 98.23% and 99.83% respectively and possessed excellent physical and chemical binding stability. Meanwhile, the coating layer resulted in the antifouling ability without damaging the membrane intrinsic transport characteristics. As for synthetic municipal wastewater treatment, the water flux of CTA FO membrane decreased approximately 49% of the initial flux after running for 14 days. In contrast, the flux decline rate of TA/DETA (24)-Ag CTA membrane was about 37%. Furthermore, less foulant deposition and higher recovery rate of water flux was observed for TA/DETA (24)-Ag CTA membrane, implying that the modified membrane effectively alleviated membrane fouling and processed a lower flux decline during municipal wastewater treatment. It was attributed to the enhanced surface hydrophilicity and antibacterial property of the coating layer, which improved antifouling property.

Employing Atomic Force Microscopy (AFM) for Microscale Investigation of Interfaces and Interactions in Membrane Fouling Processes: New Perspectives and Prospects

Membrane fouling presents a significant challenge in the treatment of wastewater. Several detection methods have been used to interpret membrane fouling processes. Compared with other analysis and detection methods, atomic force microscopy (AFM) is widely used because of its advantages in liquid-phase in situ 3D imaging, ability to measure interactive forces, and mild testing conditions. Although AFM has been widely used in the study of membrane fouling, the current literature has not fully explored its potential. This review aims to uncover and provide a new perspective on the application of AFM technology in future studies on membrane fouling. Initially, a rigorous review was conducted on the morphology, roughness, and interaction forces of AFM in situ characterization of membranes and foulants. Then, the application of AFM in the process of changing membrane fouling factors was reviewed based on its in situ measurement capability, and it was found that changes in ionic conditions, pH, voltage, and even time can cause changes in membrane fouling morphology and forces. Existing membrane fouling models are then discussed, and the role of AFM in predicting and testing these models is presented. Finally, the potential of the improved AFM techniques to be applied in the field of membrane fouling has been underestimated. In this paper, we have fully elucidated the potentials of the improved AFM techniques to be applied in the process of membrane fouling, and we have presented the current challenges and the directions for the future development in an attempt to provide new insights into this field.