Impact of pulsed ultrasound on bacteria reduction of natural waters

Abstract

There is a limited work on the use of pulsed ultrasound for water disinfection particularly the case of natural water. Hence, pulsed ultrasound disinfection of natural water was thoroughly investigated in this study along with continuous ultrasound as a standard for comparison. Total coliform measurements were applied to evaluate treatment efficiency. Factorial design of 2(3) for the tested experimental factors such as power, treatment time and operational mode was applied. Two levels of power with 40% and 70% amplitudes, treatment time of 5 and 15 min and operational modes of continuous and pulsed with On to Off ratio (R) of 0.1:0.6 s were investigated. Results showed that increasing power and treatment time or both increases total coliform reduction, whereas switching from continuous to pulsed mode in combination with power and treatment time has negative effect on total coliform reduction. A regression model for predicting total coliform reduction under different operating conditions was developed and validated. Energy and cost analyses applying electrical and calorimetric powers were conducted to serve as selection guidelines for the choosing optimum parameters of ultrasound disinfection. The outcome of these analyses indicated that low power level, short treatment time, and high R ratios are the most effective operating parameters.

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

“…However, the overall impact of UE depends on the frequency used in the disinfection process. When the power is too high and the sonication time is prolonged, the logarithm of the survival rate of bacteria (such as E. coli) declines abruptly [80] , [81] , [82] , [83] , [84] , [85] , [86] , [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] .…”

Pengaruh Variasi Waktu Paparan Gelombang Ultrasonik dalam Mengurangi Jumlah Bakteri coliform pada Sampel Air Sungai Kahayan

“…Penelitian tentang penggunaan gelombang ultrasonik untuk membunuh bakteri pernah dilakukan oleh Zhou, dkk pada tahun 2009 untuk membunuh bakteri E. coli pada daun bayam selama 0-4 menit, pemberian treatment gelombang ultrasonik memberikan dampak signifikan terhadap menurunnya jumlah koloni bakteri pada bayam [6]. Selain itu terdapat pemanfaatan gelombang ultrasonik untuk mengurangi jumlah Salmonella typhimurium pada susu, pengkajian efek gelombang ultrasonik pada air kaldu sapi, dan mengontrol mikroba pada air [7][8][9][10][11][12]. Pemanfaatan gelombang ultrasonik sebagai antibakteri coliform yang dilakukan dalam penelitian ini telah diawali dengan penelitian tentang rancang bangun sistem pembangkit gelombang ultrasonik sebagai metode alternatif menurunkan jumlah bakteri E. coli pada proses penjernihan air.…”

Effect of air gap membrane distillation parameters on the removal of fluoride from synthetic water

“…It is also clear that the order in which the experiments were conducted had no effect on the distribution of errors as illustrated by the random variation of the residuals around zero in Figs. 7a and 7b [24,25]. Further diagnostic statistical tests were conducted on the residuals of fluoride removal using both D on and N 20 membranes data to explore time-related effects on error distribution and to verify the random distribution of the errors throughout the experiments.…”