SILVER NANOPARTICLES ADHERED TO CORK AS A FILTER MEDIUM FOR WATER DISINFECTION Lina Garcia1,*, Angel Gallegos2, Rosanna Margalef2, Marc Vives2, Lorena Aguilar2, Juan Casas1, Jordi Morató2 1
Grupo de Investigación en Ciencia e Ingeniería en Sistemas Ambientales (GCISA), Civil Engineering Faculty, Universidad del Cauca, Popayán, Colombia *Mail:
[email protected] 2 UNESCO Chair on Sustainability, Laboratori de Microbiologia Sanitaria i Mediambiental (MSM-Lab), Polytechnic University of Catalunya (UPC), Terrassa, Spain.
INTRODUCTION Nowadays there is a major concern in the public health field: waterborne diseases, specifically those caused by infectious agents. According to the World Health Organization (WHO) one tenth of the global illnesses could be prevented by improving the water supplies [1], [2]. Water source Worldwide diseases
Purification steps
• Disinfection DISADVANTAGES: Limited efficiency against certain pathogens By-products generation
Potable water
Figure 2. Cork-nanoparticles fabrication.
The CLIMATE CHANGE has worsened the concerns for waterborne diseases. It is crucial to search strategies to solve any possible emergency situation. Rainfall events Higher temperatures
Floods
Microbial proliferation
In the current study the antimicrobial activity of an innovative filter device, filled with cork with adhered silver nanoparticles, has been evaluated in front of Escherichia coli [3], [4].
METHODS
Figure 3. Laboratory-scale assays
CONCLUSION
FILTER CONSTRUCTION AND DESIGN: after assembling the device [Figure 3] and packaging of the cartridge with the treated cork, a volume of 50 ml of inoculated water was assessed to perform the experiment by an intermittent flow through the cartridge [5], [6]. SILVER NANOPARTICLES ADHERED TO CORK PRODUCTION: the fabrication is performed following the methodology previously described by Francesko et al. [4] from the Group of Molecular and Industrial Biotechnology (GMI) of the UPC. This method consists on an enzymatically catalysed process using a silver nanoparticles solution, obtained by a series of chemical reactions, and the cork donated by the Catalan Cork Agency, whose surface is previously prepared by washing it with different solutions [Figure 2].
RESULTS
Generally, the use of innovative strategies, as the one described on the present study, contribute to the resilience process in front of the climate change, phenomena that causes several effects triggering disequilibrium to the earth ecosystems. For instance, higher temperatures or floods caused by heavy rainfall events may origin a higher bacterial proliferation, which may be the basis of infectious diseases spreading both in humans and animals. Promising technology for water disinfection
E. Coli inoculated water
Silver nanoparticles adhered to cork filter Easy application
Easy automation
Possibility of coupling other treatments
Adaptability to the environmental field
Potential use in small communities
Antimicrobial activity 1.00E+06
Reduced bacterial load in the effluent
[E. coli] log cfu/ml
1.00E+05 1.00E+04 1.00E+03
REFERENCES
1.00E+02 1.00E+01 1.00E+00 0
24
48
72
96
120
Hours
Figure 1. Antimicrobial activity of the device.
The results of the assays described above show that our filter design triggers a decrease in the E. coli load from the inoculated water [Figure 1]: the initial bacterial concentration of the inoculated water was 2·105 cfu/ml and after 5 days (120 h) it was 6·103.
[1] World Health Organization (WHO). 2014. Water. Website of the World Health Organization: http://www.who.int/topics/water/es/ [consulted on August 26, 2015]; [2]World Health Organization (WHO). 2006. Guidelines for Drinking Water Quality. Website of the WHO: http://www.who.int/es/ [consulted on August 26, 2015]; [3] HUNTER, P.R. 2003. Climate change and waterborne and vector-borne disease. Journal of Applied Microbiology, 94, 37–46; [4]FRANCESKO, A. et al. 2015. Enzymatic functionalization of cork surface with antimicrobial hybrid biopolymer/silver nanoparticles. ACS Appl Mater Interfaces, 18, 9792-9; [5] NALWANGA, R., QUILTY, B., MUYANJA, C., FERNANDEZ-IBANÑEZ, P., & MCGUIGAN, K. 2014. Evaluation of solar disinfection of E. coli under Sub-Saharan field conditions using a 25L borosilicate glass batch reactor fitted with a compound parabolic collector. Revista Solar Energy, 100, 195–202; [6] ESCOLÀ, M. & BESTER. K. 2015. Can those organic micropollutants that are recalcitrant in activated sludge treatment be removed from wastewater by biofilm reactors (slow sand filters)?. Science of the Total Environment, 506, 315–322.
