Inactivation of E. coli Using Flow-Through Ultrasound and Ultraviolet Light Reactors in Series

Recent trends in the applications of sonochemical reactors as an advanced oxidation process for the remediation of microbial hazards associated with water and wastewater: A critical review

“… Microorganism (introduced dose in CFU/mL) Experimental conditions (Utrasonication frequency and power density) and other hybrid systems Media of sample and volume Remarks Ref. B.subtilis spores (10 6 ), Escherichia coli (250) 20 KHz frequency, 38.5, 50, 285.7 W/cm 2 power intensity 120 mL distilled water B. subtilis was resistant, but E. coli was inactivated by 2.97 ± 0.58-logs in 5 min at 817 kHz [167] Microcystis aeruginosa (1.3 × 10 6 ) 20–1137 KHz frequency, 0.45 W/cm 3 power density 300 mL sample Higher ultrasonic frequencies (60 % inactive) more effective than lower frequencies (30 % inactive) [168] Bacillus subtilis (10 4 ) Dual-frequency (70 + 33 KHz and 70 + 100 KHz) and 0.025 W/cm 3 power densisty 30 L/h flow-through pilot scale It is efficient treatment with 70 + 100 KHz after pretreatment with NaOCl and 17 + 33 KHz [169] Microcystis aeruginosa (10 6 ) 120 KHz to 1120 KHz frequency with 0.01–0.09 power density Ultrapure water sample Cells are more inactivate at 430 and 740 KHz than other frequencies with 80–90 % turbidity removal [170] Escherichia coli (1 × 10 9 ) 2 MHz frequency 0.1 mL of 3 % tryptic soy broth 2-log disinfection is achieved within 10 min [171] E. coli (10 5 ) 20 KHz frequency with 11 W/cm 2 power intensity + 2.25 mW/cm 2 UV intensity 70 mL/min flow through 0.9 % saline solution A synergistic ehnacement is observed under utrasonication and UV light inactivation [172] Fecal coliform bacteria (3.67 × 10 2 −9.48 × 10 4 ) 28 KHz frequency + 254 nm UV light 900–2100 L/h continuous flow baffled secondary effluents A synergistic effect observed. 4.24 log reduction observed at specific energy, 0.219 kWh/m 3 and 1200 L/h [173] E. coli (10 8 ) 33 KHz frequency + 0.035 mW/cm 2 UV inten...…”