Activated carbons: efficient materials for the removal of multi- resistant bacteria

Abstract

The rapid emergence of multi-resistant bacteria is occurring worldwide being hospital effluent a major source of these microorganisms. To remove these bacteria possible strategies are those involving activated carbon that due to their tunable properties can be suitable adsorbents for different types of microorganisms, for example Gram + or Gram – bacteria. The objective of this study was to test an activated carbon (AC) commercialized for water treatment purpose to reduce the content of bacteria commonly detected in hospital wastewater. The assays were made using the carbon in two different granulometries against multi-resistant strains: Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus. The adsorption tests were performed following a procedure adapted from Naka et al. [1]. In any case in parallel with the adsorption assays, the growth of the bacteria was also assessed.The results displayed at Figure 1 show that carbon AC allows a continue decrease of bacteria amount in the liquid media, despite the continuous increase of bacteria demonstrated by the blank experiment. The images displayed in Figure 2 (b) and (c) show the cells adherent to carbon, after 90 minutes of contact. These preliminary results allow us to conclude that activated carbon can be used to increase the removal efficiency of multi-resistant bacteria present in hospital wastewater. Acknowledgments The financial support of FCT to CQB (PEst-OE/QUI/UI0612/2013) is acknowledged. [1] K. Naka, S.T. Watarai, K. Inoue, Y. Kodama, K. Oguma, T.Yasuda, H.J. Kodama, 2001, Veter. Med. Science., 63, 281-285.