Sonochemical disinfection of municipal wastewater

Water and wastewater disinfection by ultrasound irradiation - a critical review

“…coli inactivation exhibited pseudo-first order behaviour and its extent was found to enhance with increasing intensity: Hua and Thompson (2000) investigated the effect of ultrasound density in the range 270-460 W l -1 at a frequency of 20 kHz and they observed that the extent of E. coli inactivation became about 2.8 Log after 60 min at the highest density of 460 W l -1 . Similarly, Antoniadis et al, (2007), performed experiments at laboratory scale, using both synthetic municipal and septic tank wastewaters, in order to verify US effects on E. coli inactivation. In both cases, 100 ml of wastewater were subjected to ultrasonic irradiation by a device operating at a fixed frequency of 80 kHz and a variable electric power output up to 150 W, connected to a titanium-made horn with a 7 mm tip.…”

Ultrasound enhancement of near-neutral photo-Fenton for effective E. coli inactivation in wastewater

“…Their action is based on the production of the extremely oxidizing hydroxyl radical ( Å OH) [1], which can attack the chemical structure of the microorganisms' cell wall and inactivate them [2]. Ultrasound has been extensively studied as an AOP, targeting microorganism inactivation, such as bacteria, viruses etc., by either low ($20 kHz) or high frequencies (200+ kHz) [2][3][4] and [5].…”

“…Their action is based on the production of the extremely oxidizing hydroxyl radical ( Å OH) [1], which can attack the chemical structure of the microorganisms' cell wall and inactivate them [2]. Ultrasound has been extensively studied as an AOP, targeting microorganism inactivation, such as bacteria, viruses etc., by either low ($20 kHz) or high frequencies (200+ kHz) [2][3][4] and [5]. This method is exploiting the direct mechanical action of the cavitation bubble implosion (low frequencies) as well as the additional production of H 2 O 2 and Å OH radicals during cavitation (high frequencies); the propagation of ultrasound waves in the aqueous medium initiates the aforementioned actions, by the generation of extreme temperature and pressure conditions [6], which have a proven bactericidal effect [7][8][9], and [10].…”

“…It is also verified that apart from low frequency/high power ultrasound systems [13,14], high frequency/low power processes have been proven to efficiently inactivate microorganisms [8,15,16]. However, ultrasound already requires high intensities to achieve total inactivation of microorganisms, and therefore, is considered an expensive application for large volumes of water [2]. Considering all the above, it should be used preferably as a complementary disinfecting method [2].…”

“…However, ultrasound already requires high intensities to achieve total inactivation of microorganisms, and therefore, is considered an expensive application for large volumes of water [2]. Considering all the above, it should be used preferably as a complementary disinfecting method [2].…”