A Comprehensive Review of Polymeric Wastewater Purification Membranes

Development of Composite Nanostructured Electrodes for Water Desalination via Membrane Capacitive Deionization

Novel two-layer nanostructured electrodes are successfully prepared for their application in membrane capacitive deionization (MCDI) processes. Nanostructured carbonaceous materials such as graphene oxide (GO) and carbon nanotubes (CNTs), as well as activated carbon (AC) are dispersed in a solution of poly(vinyl alcohol) (PVA), mixed with polyacrylic acid (PAA) or polydimethyldiallylammonium chloride (PDMDAAC), and subsequently cast on the top surface of an AC-based modified graphite electrode to form a thin composite layer that is cross-linked with glutaraldehyde (GA). Cyclic voltammetry (CV) is performed to investigate the electrochemical properties of the composite electrodes and desalination experiments are conducted in batch mode using a MCDI unit cell to investigate the effects of i) the nanostructured carbonaceous material, ii) its concentration in the polymer blend, and iii) the molecular weight of the polymers on the desalination efficiency of the system. Comparative studies with commercial membranes are performed proving that the composite nanostructured electrodes are more efficient in salt removal. The improved performance of the composite electrodes is attributed to the ion exchange properties of the selected polymers and the increased specific capacitance of the nanostructured carbonaceous materials. This research paves the way for wider application of MCDI in water desalination.

Impact of silver-doped alumina nanocomposite on water decontamination by remodeling of biogenic waste

The main cause of various fatal diseases in humans and animals is environmental pollution. Ag-doped alumina nanocomposite was prepared using coffee husk extract with a large BET surface area of 126.58 m² g^-1 and investigated for its antibacterial potential against both bacterial strains Escherichia coli and Salmonella typhimurium, and observed as an effective sorbent for removing the water pollution dye indigo carmine (IGC). The lowest concentration of the nanocomposite and the maximum contact time required to achieve complete inhibition of bacteria present in the contaminated water, as well as the capacity of sorption of IGC, were investigated. The results showed that the minimum inhibitory concentration of the Ag-doped alumina nanocomposite was 12 µg mL^-1 for both bacterial strains, with the highest inhibition occurring in E. coli. Moreover, the nanocomposite exhibited an experimental qt of 462.7 mg g^-1 from 160 mg L^-1 IGC solution at 50 °C and followed the Langmuir model. The thermodynamic results showed that the process was endothermic, spontaneous, and physisorptive. The nanocomposite was used to fully treat water samples contaminated with 10 mg L^-1 concentrations of IGC. For six consecutive cycles, the reuse research showed an average efficiency of 95.72 ± 3.6%. Consequently, the synthesized Ag-doped alumina nanocomposite is suitable for treatments of contaminated water.

Polymer/Graphene Nanocomposite Membranes: Status and Emerging Prospects

Graphene is a unique nanocarbon nanomaterial, frequently explored with polymeric matrices for technical purposes. An indispensable application of polymer/graphene nanocomposites has been observed for membrane technology. This review highlights the design, properties, and promising features of the polymer/graphene nanomaterials and nanocomposite membranes for the pervasion and purification of toxins, pollutants, microbials, and other desired contents. The morphology, pore size, pore structure, water flux, permeation, salt rejection, and other membrane properties are examined. Graphene oxide, an important modified form of graphene, is also utilized in nanocomposite membranes. Moreover, polymer/graphene nanofibers are employed to develop high-performance membranes for methodological purposes. The adaptability of polymer/graphene nanocomposites is observed for water management and purification technologies.

Recent advances and applications of polymeric materials in healthcare sector and COVID-19 management

The coronavirus disease pandemic is considered at its worst and all nations are collectively fighting to improve global public health. In this outlook, polymers and their related materials (including plastics) are the primary sources in the manufacturing of medical and personal protective equipment. Plastics can be mass-produced, economical, and sterilized, which makes them an inevitable material in the medical and healthcare sector. Along with plastics, antibacterial and antiviral coatings, polymeric nanomaterials and nanocomposites, and functional polymers have become excellent materials for COIVD-19. This review centres on the applications of polymer materials in managing the COVID-19 outbreak. Moreover, the utilization of plastics with its healthcare applications are reviewed. Apart from this, major challenges and future directions of these materials have also been discussed. This review will help aspiring researchers to develop the basic understanding of polymeric materials currently employed in medical sector.