The development and evaluation of electrolysis in conjunction with power ultrasound for the disinfection of bacterial suspensions

Abstract

There is an increasing incidence in health problems related to environmental issues that originate from inadequate treatment of potable waters. This has compelled scientists and engineers to engage in innovative technologies to achieve a maximum disinfection at affordable costs. Some species of bacteria produce colonies and spores that can agglomerate in spherical clusters and thus protect organisms on the inside of the cluster against biocidal attack. Flocs of fine particles (e.g., clay) can entrap bacteria and this can also protect them against the biocides. Other bacteria have the ability to mutate, thus building up resistance to conventional biocides (e.g., chlorine). Ultrasound has been shown to be effective in improving the effectiveness of biocides such as chlorine. The aim of this present study was to investigate the effect of electrolysis and power ultrasound as a disinfection treatment and to provide a greater knowledge of the fundamentals of disinfection through the production of hypochlorite in situ from saline solution via electrolysis. The electrode materials investigated were, carbon (felt and graphite), copper and stainless steel rods. The results show that sonication appears to amplify the effect of electrolysis. A combination of both treatments is significantly better than sonication or electrolysis alone.

Sonochemical disinfection of municipal wastewater

“…Nevertheless, there is a drive towards the use of ultrasound in decontamination as an adjunct to other techniques because some microorganisms are becoming resistant to existing disinfection techniques involving biocides, ultraviolet light, and heat treatment. In this view, recent studies have dealt with the use of low frequency ultrasound (in the range 20-40 kHz) alongside ozone [6], ultraviolet irradiation [7], hydrodynamic cavitation [8], electrolysis [9], chlorination [10][11][12], and heterogeneous catalysts (i.e. activated carbon, ceramic, zinc, and titanium dioxide) [13,14], and reported that enhanced disinfection efficiencies could be achieved with the combined treatments.…”

Sonoelectrochemistry in Environmental Applications

“…Joyce et al studied the electrolytic production of hypochlorite in conjunction with power ultrasound for the disinfection of Klebsiella pneumonia [68] and Escherichia coli [69] saline suspensions. Although sonication alone can provide powerful disinfection, a large amount of energy is required.…”

Application of cavitational reactors for water disinfection: Current status and path forward

“…The turbulence induced by ultrasound was also beneficial in disintegration of the particle agglomerates and particle size generally found in sewage effluent was reported to reduce from 40 to 1 mm. Joyce et al (2003b) investigated the effect of electrolysis and power ultrasound as a disinfection treatment for Klebsiella pneumonia. Individual operation of sonication resulted in about 40% disinfection in 60 min of treatment whereas individual electrolysis operation at 150 mA supplied current resulted in complete disinfection in only 15 min of treatment.…”