Article

Electrochemical multiwalled carbon nanotube filter for viral and bacterial removal and inactivation.

Department of Chemical and Environmental Engineering, Yale University , New Haven, Connecticut 06520-8286, United States.
Environmental Science & Technology (Impact Factor: 5.48). 03/2011; 45(8):3672-9. DOI: 10.1021/es2000062
Source: PubMed

ABSTRACT Nanotechnology has potential to offer solutions to problems facing the developing world. Here, we demonstrate the efficacy of an anodic multiwalled carbon nanotube (MWNT) microfilter toward the removal and inactivation of viruses (MS2) and bacteria (E. coli). In the absence of electrolysis, the MWNT filter is effective for complete removal of bacteria by sieving and multilog removal of viruses by depth-filtration. Concomitant electrolysis during filtration results in significantly increased inactivation of influent bacteria and viruses. At applied potentials of 2 and 3 V, the electrochemical MWNT filter reduced the number of bacteria and viruses in the effluent to below the limit of detection. Application of 2 and 3 V for 30 s postfiltration inactivated >75% of the sieved bacteria and >99.6% of the adsorbed viruses. Electrolyte concentration and composition had no correlation to electrochemical inactivation consistent with a direct oxidation mechanism at the MWNT filter surface. Potential dependent dye oxidation and E. coli morphological changes also support a direct oxidation mechanism. Advantages of the electrochemical MWNT filter for pathogen removal and inactivation and potential for point-of-use drinking water treatment are discussed.

0 Bookmarks
 · 
249 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The continued depletion of fresh drinking water resources throughout the world has increased the need for a variety of water treatment and recycling strategies. Conventional wastewater treatment processes rely on extensive chemical post-disinfection to comply with the stringent microbiological safety for water reuse. When well designed and operated, membrane bioreactors (MBRs) can consistently achieve efficient removals of suspended solids, protozoa and coliform bacteria. Under optimal conditions, MBR systems can also significantly remove various viruses and phages. This paper provides an in-depth overview of the mechanisms and influencing factors of pathogen removal by MBR and highlights practical issues, such as reduced chemical disinfectant dosing requirements and associated economic and environmental benefits. Special attention has been paid to the aspects, such as membrane cleaning, membrane imperfections/breach and microbial regrowth, in the distribution system on the overall pathogen removal performance of MBR.
    Water 11/2014; 6(12). · 1.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Biofouling is a major problem in environmental membrane separations because it leads to higher operating pressures, more frequent chemical cleaning, shortened membrane life, and compromised product water quality. The paper presents an overview on fabrication and properties of low-biofouling composite membranes for pressure-driven membrane processes. At first, biofouling phenomena and membrane surface properties which affect membrane biofouling have been discussed and the main objectives for the development of composite membranes for biofouling mitigation have been outlined. Thereafter the recent studies on the preparation of low-biofouling composite membranes using interfacial polymerization, surface grafting, coating of a protective layer and surface modification with nanoparticles have been critically summarised.
    Desalination 01/2015; 356. · 3.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: CNT loading significantly improved the aerosol filtering performances of base filter.•CNT filter's QF at 0.2 mg/cm2 was higher than those of surgical and activated carbon masks.•CNT filters were observed to improve breathability over some available facepiece respirators.
    Journal of Aerosol Science 10/2014; · 2.71 Impact Factor

Full-text (2 Sources)

Download
379 Downloads
Available from
May 29, 2014