Membrane technology has been used in desalination and wastewater treatment due to its many advantages such as ease of operation, smaller footprint, higher efficiency, and lower chemical consumption over conventional technologies. However, there are still some challenges associated with membrane technology, viz. fouling, selectivity to uncharged contaminants in pressure-driven membranes, and energy consumption without compromising the water quality. These necessitate the need for new generation membranes with better selectivity with antifouling capability. Advancements in the field of materials science and membrane preparation processes are giving new possibilities for mitigating these problems of conventional membrane filtration with the use of electroconductive membranes or ECMs. ECMs combine the separation effect of the membrane with the electrical effects of the conducting elements. Over the last few years, ECMs have been applied using different conductive elements such as graphene, conductive polymers, carbon nanotubes (CNTs), etc. ECMs is a rapidly growing field, and they have shown potential for desalination and wastewater treatment. Therefore, there is a need for an updated review focusing on the different aspects of ECMs. Moreover, there is a lack of reviews on ECM synthesis and fabrication, application, and action of mechanism in the broad range of membrane filtration, such as pressure-driven, thermal driven, and osmotically driven membrane processes. Thus, this review is focused on the synthesis and fabrication of ECMs, conductive elements used, and antifouling mechanisms of ECMs under positive, negative, and alternate biases. The important ECM studies so far conducted in commonly used pressure-driven membrane processes, along with the recent advancements made in the field of FO and MD using ECM have also been reviewed. Moreover, this review provided the current status of the energy and cost aspects of ECMs along with the current challenges and possible future development paths for the ECMs.

Interest in the pathogenesis, detection, and prevention of viral infections has increased broadly in many fields of research over the past year. The development of water treatment technology to combat viral infection by inactivation or disinfection might play a key role in infection prevention in places where drinking water sources are biologically contaminated. Laser-induced graphene (LIG) has antimicrobial and antifouling surface effects mainly because of its electrochemical properties and texture, and LIG-based water filters have been used for the inactivation of bacteria. However, the antiviral activity of LIG-based filters has not yet been explored. Here we show that LIG filters also have antiviral effects by applying electrical potential during filtration of the model prototypic poxvirus Vaccinia lister. This antiviral activity of the LIG filters was compared with its antibacterial activity, which showed that higher voltages were required for the inactivation of viruses compared to that of bacteria. The generation of reactive oxygen species, along with surface electrical effects, played a role in the mechanism of virus inactivation. This new property of LIG highlights its potential for use in water and wastewater treatment for the electrochemical disinfection of various pathogenic microorganisms, including bacteria and viruses.

Pathogenic virus inactivation is crucial to eliminate the substantial risk they cause to human health and to ensure safe drinking water. Conventional water disinfection methods generate harmful disinfection by-products and have high energy demands or the possibility of regrowth of microorganisms. Alternatively, emerging techniques like electrochemical disinfection have opened new opportunities in water treatment by using efficient electrodes to inactivate microbes. Furthermore, graphene-based electrodes have shown their effectiveness at low voltage for electrochemical disinfection. Laser-induced graphene (LIG) is a single-step, low-cost fabrication technique of graphene surfaces, and its catalytic activity can be improved further by doping. In the present study, we have fabricated titanium suboxide (TSO)-doped LIG electrodes and filters in a single step for electrochemical virus inactivation. Three model surrogates with structural resemblance to enteric viruses, viz. bacteriophages MS2, T4, and Phi6, were employed during the disinfection experiments. In the batch mode, under varying voltages and TSO doping concentration, the highest virus inactivation was attained at 2.5 V using LIG-TiO_x10 electrodes. Subsequently, LIG-TiO_x filters were fabricated where the complete removal of ∼6 log was achieved for MS2 at 2.5 V, and for T4 and Phi6 at 10 V. The trend in inactivation efficiency in both operating conditions was MS2 > Phi6 > T4, highlighting the varying susceptibilities between the viruses to disinfection. Furthermore, the viruses' inactivation mechanism was recognized as combining nanofiber-enhanced electric field-induced electroporation and electrochemically generated reactive species. The present work will help to design electrochemical disinfection devices and show how the best efficiency can be achieved for different viruses in water purification applications.