STUDY OF BIOCIDAL PROPERTIES OF OZONE, PLASMA-CHEMICAL AND COMBINED TREATMENTS ON ARTIFICIALLY CONTAMINATED MODEL WATER SOLUTIONS

Study was carried out to evaluate the biocidal effects of plasma-chemical methods for use by ozone, electric discharge with water electrode (plasma-chemical treatment) or their combination of artificially contaminated water. The preliminary contamination was achieved by inoculating water with suspensions of test cultures, including Escherichia coli #12 and Aspergillus flavus. The results showed that separate exposure to ozone or discharge with water electrode resulted in insignificant fungistatic effect on Aspergillus flavus and bacteriostatic effect on Escherichia coli #12 after exposure times of 2, 2.5, and 3 h, achieving inhibition rates of about 64%. Joint combined ozone and discharge with water electrode treatment during 2.5…3 h of water contaminated with a mixture of Escherichia coli #12 and Aspergillus flavus significantly inhibited microorganisms, causing destruction of the cell membrane and genetic material, resulting in the death of 95% of the cells. Such kind of treatment effectively improved the microbiological quality of drinking water.