Resumen de Mineral water disinfection using ultrasound

Carmen Paula Gómez Pérez, María Teresa Pérez Iglesias, José Luis Legido Soto, Guillermo Moreiras Avendaño, Ana Gago Martínez, Lorena Vázquez Iglesias, Francisco Javier Rodríguez Berrocal, Cristina Vázquez Gómez

• The objective of this study is to evaluate the effects of ultrasound waves on the viability of different bacteria in mineral waters such as spa thermal waters. The application of ultrasound for the disinfection of water can be an alternative to other methods, such as, chlorination, ozonation, UV irradiation. Sonication was performed using a commercial ultrasonic bath at constant frequency of 40 kHz for 10 to 20 minutes.

  Experiments were carried out at a concentration of 106 CFU mL-1 and a constant temperature of 309.65 K.

  The effects of the ultrasounds waves on bacterial growth were analyzed using a Calvet microcalorimeter.

  By plotting heat voltage difference versus time, we are able to obtain the graphs of Staphylococcus epidermidis and Escherichia coli, with and without ultrasound treatment.

  Furthermore, the heat released by microorganisms in the treated and untreated samples sonicated for 24 hours was calculated. The ultrasound treatment appears to be effective in inhibiting the growth of S. epidermidis, but not in the case of E. coli which presented greater resistance at the same experimental conditions.

  This study also showed microcalorimetry as an efficient technique to determine the effect of ultrasound waves on bacterial growth.