Wyniki wyszukiwania - BazTech

1

Influence of Low-Frequency Ultrasound on the Disintegration of Coliform and Fecal Coliform Bacteria

Hawrylik Eliza, Butarewicz Andrzej

Journal of Ecological Engineering

|

2021

|

Vol. 22, nr 9

192--197

EN

Wastewater contains an abundance of pathogenic microorganisms, which, if they infiltrate into the environment, can cause many bacterial diseases. The lack of widespread use of the wastewater disinfection process raises more and more concerns about the sanitary quality of the wastewater leaving treatment plants. This article aimed to test the effectiveness of the ultrasonic disintegration process against coliform bacteria and fecal coliforms in the treated wastewater. The paper presents the research on the use of ultrasound with a frequency of 20 and 40 kHz, with a variable and constant operating mode of an ultrasonic cleaner. The obtained test results confirm the effectiveness of the applied method. In most of the analyzed cases, 25-minute sonication reduced the number of tested microorganisms by over 90% compared to the control sample. Ultrasonic disintegration can therefore be successfully used in municipal wastewater treatment plants. The use of ultrasound for disinfection can improve the sanitary safety of the wastewater discharged into water or soil.

2

The usage of ultrasounds to disintegrate escherichia coli bacteria contained in treated wastewater

Hawrylik Eliza

Architecture Civil Engineering Environment

|

2019

|

Vol. 12, no. 3

131--136

EN

Sewage and sewage sludge is a place of the occurrence of many microorganisms, including pathogenic and relatively pathogenic bacteria. They may reach other environments, e.g. receiver waters or soil, thus creating a biological threat. The aim of this paper was to study, in laboratory conditions, the effect of low-frequency ultrasound on the disintegration of Escherichia coli bacteria present in purified wastewater. E. coli bacilli and ultrapure water were used for the study. The samples were exposed to ultrasounds at 20 and 40 kHz for variable time of sonication and at two different modes of the ultrasonic cleaner operation: continuous and pulsed. Studies have shown that ultrasound has an effective impact on E. coli bacilli. Already the 3-minute interaction of ultrasounds at 20 kHz with the pulsation mode of impact of the device caused a decrease in the number of these bacteria by over 90%. The 20-minute operation of 40 kHz ultrasound waves resulted in a decrease in the amount of bacteria by nearly 70% compared to the control. The obtained results, therefore, indicate the possibility of using the disintegration process of low frequency ultrasounds for removing Escherichia coli bacteria present in treated wastewater.

3

Electrical Characterization of 65 W Cubic Sonoreactor with Horizontally Stacked Transducers

Kerdthongmee P., Pholnak C., Sirisathitkul C., Danworaphong S.

Archives of Acoustics

|

2017

|

Vol. 42, No. 1

149--153

EN

A sonoreactor was assembled with stacked lead zirconate titanate transducers. These transducers were attached on one side of a 10×10×10 cm3 chamber and driven by an integrated circuit power amplifier. The impedance of the reactor was analyzed in order to determine a matching inductance. The electrical frequency could be varied from 20 to 50 kHz and the electrical output power was adjustable up to 65 W. The highest power was obtained in the case of resonance at 31 kHz and the maximum temperature at the heat sink of the amplifier rose to 42.0ºC. Both acoustic cavitation and mechanical effects could be utilized in this sonoreactor for a variety of purposes including sonochemical synthesis, ultrasonic cleaning and microbial cell disruption.