Comparison between effects of manothermosonication and isolated ultrasonic techniques on microbial inactivation of a hospital laundry effluent

Microbial inactivation using only Ultrasound (US) vibrations presents considerable advantages by applying green techniques with non-generation of greenhouse gases, eliminating chemicals, and operating conditions close to environmental conditions. However, industrial effluent treatment systems have been investigated as a microbial step, isolated US associated thermal (T) manometric (P) techniques. A stainless-steel bench prototype was built for the present study, in continuous mode, 2.5 L volume test chamber. The indicator microorganism detected hospital laundry located Agreste region state Pernambuco, Brazil, E. coli bacterium. In addition effect, US/T, US/P, US/T/P combinations were obtained central composite design (CCD). factors used CCD frequency, hydraulic detention time, temperature, pressure. results showed that lethality rate increased frequency time but reduced when increasing temperature from 30°C 50°C pressure between 1.0 bar 1.8 bar. Isolated ultrasonic vibrations, at 120 kHz 10-minute HRT, reached an efficiency 98%. Such value found thermomannosonic condition around 40 min. use vibration technique proved advantageous, mainly due efficient potential energy chemical reductions.