Versatile Silver-Nanoparticle-Impregnated Membranes for Water Treatment: A Review

Abstract

Increased affordability, smaller footprint, and high permeability quality that meets stringent water quality standards have accelerated the uptake of membranes in water treatment. Moreover, low pressure, gravity-based microfiltration (MF) and ultrafiltration (UF) membranes eliminate the use of electricity and pumps. However, MF and UF processes remove contaminants by size exclusion, based on membrane pore size. This limits their application in the removal of smaller matter or even harmful microorganisms. There is a need to enhance the membrane properties to meet needs such as adequate disinfection, flux amelioration, and reduced membrane fouling. To achieve these, the incorporation of nanoparticles with unique properties in membranes has potential. Herein, we review recent developments in the impregnation of polymeric and ceramic microfiltration and ultrafiltration membranes with silver nanoparticles that are applied in water treatment. We critically evaluated the potential of these membranes in enhanced antifouling, increased permeability quality and flux compared to uncoated membranes. Despite the intensive research in this area, most studies have been performed at laboratory scale for short periods of time. There is a need for studies that assess the long-term stability of the nanoparticles and the impact on disinfection and antifouling performance. These challenges are addressed in this study and future directions.

Highly efficient aramid fiber supported polypropylene membranes modified with reduced graphene oxide based metallic nanocomposites: antimicrobial and antiviral capabilities

“…These results align with previous research demonstrating the antimicrobial and antiviral efficacy of nanomaterial-enhanced membranes. 32,33 Our study further highlights the synergistic effects of combining multiple nanomaterials, contributing to the development of more efficient water purication technologies.…”

Current Status and Advancement of Nanomaterials within Polymeric Membranes for Water Purification

“…This is because for each membrane there is a trade-off of selectivity, permeability, flux, stability, or high cost of manufacturing. ,, Furthermore, as previously mentioned, fouling remains a significant concern that limits the practicality of diverse filtration membranes, particularly those composed of polymers and ceramics. Polymeric membranes are favored because of their high flexibility and chemical stability and they can be used in processes such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis that use pressure. , They can be made from various polymeric materials such as polyether sulfone, polyamic acid, polyvinylidene, and poly(vinyl alcohol) among others. , Nanotechnology, the science that deals with creating materials through the manipulation at atomic and molecular levels, has been found to have the perspective of delivering inexpensive and operational solutions to this problem of membrane fouling, leading to improved membrane performance and hence providing access to safe drinking water to millions of people around the world . It has developed a proficient and profitable enduring solution through the adoption of innovative filtration membranes composed of various nanomaterials such as nanoparticles, carbon-based substances, and nanofibers infused into a polymeric matrix that improves the performance of conventional polymeric membranes in terms of improved water permeability, antifouling, and solute selectivity.…”

“…This is because in the presence of AgNPs, the membrane of the cell raptures in the course of endocytosis, enabling entry of the nanoparticles into the cell . They also have low toxicity to human beings and are easy to incorporate into various substrates for disinfection purposes …”

“…Different technologies that have been used to remove these contaminants from water include distillation, electrolysis, − photodegradation, , adsorption, − and filtration membrane − technology. The filtration membrane technology stands out as the best since it requires minimum and flexible operational energy, can attain high removal and separation efficiency, has high and stable filtration flux, requires low filtration pressure, has high-quality permeability, is cost effective, and is also capable of operating continuously. ,− However, these filtration membranes face the unavoidable occurrence of fouling that arises from deposits of microbes, suspended solids, and organic materials on the surface of the membrane for the duration of selective water permeation . Even with the current advancement in the field, membrane fouling is still considered a key obstacle in filtration membrane processes .…”

Surface characteristics of thin film composite polyamide membranes dictate silver nanoparticle loading efficacy

“…View Article Online 5 improving flux 28 . In the case of PA TFC membranes, AgNPs can be integrated to the PA surfaces through two main approaches, i.e., in-situ nucleation of AgNPs on the surface and ex-situ synthesis of AgNPs, which are then integrated into the monomer solutions during interfacial polymerization 23,[29][30][31] Each method has its advantages and limitations. For example, the ex-situ synthesis provides more opportunities to control the size and surface chemistry of the AgNPs that are to be integrated into the PA layer; however, such coatings cannot be regenerated once the AgNPs are depleted during operation.…”