Preventing maritime transport of pathogens: the remarkable antimicrobial properties of silver-supported catalysts for ship ballast water disinfection

Water Sci Technol. 2017 Jul;76(3-4):712-718. doi: 10.2166/wst.2017.266.

Abstract

Ship ballast water (SBW) antimicrobial treatment is considered as a priority issue for the shipping industry. The present work investigates the possibility of utilizing antimicrobial catalysis as an effective method for the treatment of SBW. Taking into account the well-known antimicrobial properties of ionic silver (Ag+), five silver-supported catalysts (Ag/γ-Al2O3) with various loadings (0.05, 0.1, 0.2, 0.5, and 1 wt%) were prepared and examined for the antimicrobial treatment of SBW. The bactericidal activity of the aforementioned catalysts was investigated towards the inhibition of Escherichia coli (Gram-negative) and Escherichia faecalis (Gram-positive) bacteria. Catalytic experiments were conducted in a three-phase continuous flow stirred tank reactor, used in a semi-batch mode. It was found that using the catalyst with the lowest metal loading, the inhibition of E. coli reached 95.8% after 30 minutes of treatment of an E. coli bacterial solution, while the inhibition obtained for E. faecalis was 76.2% after 60 minutes of treatment of an E. faecalis bacterial solution. Even better results (100% inhibition after 5 min of reaction) were obtained using the catalysts with higher Ag loadings. The results of the present work indicate that the prepared monometallic catalysts exert their antimicrobial activity within a short period of time, revealing, for the first time ever, that the field of antimicrobial heterogeneous catalysis using deposited ionic silver on a solid support may prove decisive for the disinfection of SBW.

MeSH terms

  • Anti-Infective Agents / pharmacology*
  • Catalysis
  • Disinfection / methods*
  • Escherichia coli / drug effects*
  • Ships*
  • Silver / chemistry
  • Silver / pharmacology*
  • Water / pharmacology
  • Water Microbiology
  • Water Purification / methods

Substances

  • Anti-Infective Agents
  • Water
  • Silver