The effectiveness of a multi-spark electric discharge system in the destruction of microorganisms in domestic and industrial wastewaters

Abstract

The aim of this work was to investigate the effectiveness of a high voltage multi-spark electric discharge, with pulse energy of 1 Joule, in killing microorganisms in wastewater. Wastewater from primary treated effluent arising from domestic and industrial sources was abstracted for continuous pulsed discharge disinfection. The wastewater contained a large mixed population of microorganisms (approximately 10(7) CFU ml(-1) [10(9) CFU 100 ml(-1)] total aerobic heterotrophic bacteria) including vegetative cells and spores. The electrical conductivity of the wastewater ranged from 900-1400 microS cm(-1) and it was shown that a specific energy of 1.25-1.5 J cm(-3) was required to achieve 1 log reduction in bacterial (faecal coliforms/total aerobic heterotrophs) content. This is higher than that previously shown to reduce the population of E. coli in tap water of low conductivity, demonstrating the role of total wastewater constituents, including dissolved and particulate substances, water colour and the presence of microbial spores, in effective disinfection. The system can be engineered to eradicate microbial populations to levels governed by legislation by increasing treatment time or energy input.

Evidence of lethal and sublethal injury in food-borne bacterial pathogens exposed to high-intensity pulsed-plasma gas discharges

“…While the mechanisms underlying the inactivation of micro‐organisms by PPGD have yet to be fully elucidated, it is generally considered that microbial inactivation may be attributed to the combined influence of numerous antimicrobial components formed during this plasma discharge process, such as the generation of ozone and other free radicals, free electrons, ultraviolet light, acoustic and shock waves (Espie et al. 2001; Aniplov et al. 2004).…”

“…2001; Sentandreu et al. 2006), in domestic and industrial waste water (Aniplov et al. 2002, 2004) and for the degradation of pollutants (Hao et al.…”

“…The application of high‐voltage pulses to gas‐sparged test liquids, such as laboratory‐based media (Espie et al. 2001) and domestic and industrial waster water (Aniplov et al. 2002, 2004), results in partial discharge activity and ionization of the gas that leads to complete breakdown of the gas in these liquid media.…”

Multispark Discharge in Water as a Method of Environmental Sustainability Problems Solution

“…The first attempt at such an application has been taken in [8,23]. Water treatment was carried out using wastewater directly abstracted from final effluent stream at the Livingston Wastewater Treatment Plant in West Lothian, Scotland, UK.…”

Effect of Water-Surface Discharge on the Inactivation ofBacillus subtilisDue to Protein Lysis and DNA Damage

“…23,24) Considerable attention has recently been paid to a sterilization technique for microorganisms in water by using a streamer discharge produced by very short voltage pulses because of its low energy consumption. 21,[25][26][27][28][29] However, the decomposition process for biomolecules during a pulsed-discharge treatment are not known.…”