Inactivation of Escherichia coli in water samples by sound waves

It is known that swimming pools, beaches, and drinking water resources used jointly by the majority of the community have been contaminated by micro-organisms such as bacteria. Escherichia coli (E. coli) is known to be the most dangerous and deadly food-borne disease-causing bacteria. Therefore, removal of disease-causing agents to ensure the availability of water resources is of great importance in terms of community health. Chlorination and UV illumination are commonly used methods in inactivated bacteria in water sources. However, the use of these methods is rather limited because of the negative effect of chlorine on vital health, as UV illumination can also be applied to high absorptive fluids. For this reason, new methods are needed for inactivating such bacteria. In this study, it was aimed to inactivate gram-negative bacteria (especially E. coli) in water sources with the help of sound waves. For this purpose, the sound waves obtained by the help of a piezoelectric transducer oscillating in a certain frequency are used. Piezoelectric transducers were mounted at the base of glass containers containing E. Coli and Enterococcus faecalis at a given concentration and a constant frequency oscillation was provided. Bacterial samples were exposed to sound waves for different periods of 1, 3, 6 and 15 hours in order to determine the effect of the application of sound waves on bacterial inactivation. The effect of the application period of sound waves on bacterial inactivation was determined by comparing the absorption coefficients of a certain wavelength of bacterial water samples. In the study, it was observed that the duration of exposure to sound waves at frequencies of 10kHz, 25 kHz, 40 kHz, 50 kHz, 60 kHz, 75 kHz, 100 kHz, 250 kHz, 500 kHz, 750 kHz and 1000 kHz has a considerable effect on the bacterial population. In the samples exposed to sound waves for 1 hour, bacterial populations generally did not show much change, while bacterial populations decreased in samples exposed to sound waves for 3, 6 and 15 hours. In the samples exposed to sound waves for 1 hour, bacterial populations generally did not show much change, while bacterial populations decreased in samples exposed to sound waves for 3, 6 and 15 hours. It has come to the conclusion that a suitable frequency and strong sound waves have a great potential to effectively inactivate E. Coli and Enterococcus in the water.