INFLUENCE OF HEMOLITOTROPHIC MICROBIOTA ON THE EFFICIENCY OF ANTICORROSIVE TREATMENT OF STEEL PIPELINES WITH ORTHO-POLYPHOSPHATE REAGENTS ON THE EXAMPLE OF “SEA QUEST LIQUID”

Abstract

It is noted that the overwhelming majority of water supply systems operating in Ukraine are made of steel or cast iron, which are subject to corrosion. It has been established that/ one of the ways to reduce the corrosiveness of drinking water is the use of an orthopolyphosphate preparation "SeaQuest Liquid" (TU U 20.5-V 0502222-001:2017). The results of studies of the effect of the "SeaQuest Liquid" preparation on organoleptic and physicochemical indicators of drinking water are presented. It was determined that the treatment of tap drinking water with the "SeaQuest Liquid" preparation does not affect organoleptic indicators, the average levels of which practically did not undergo significant changes during 5 months of observation and were within the hygienic standards. In water samples, the levels of substances that make up the "SeaQuest Liquid" preparation (polyphosphates, orthophosphates) were within the normative values. The quality of water treated with the "SeaQuest Liquid" orthophosphate preparation, according to the main sanitary and chemical indicators, except for iron, meets the requirements of the hygienic standards DSanPiN 2.2.4.171-10. In some water samples, the iron content in water exceeded the hygienic standard (0.2 mg/dm3) and went beyond the maximum permissible level (1.0 mg/dm3). Under the action of "SeaQuest Liquid" in water treated with sodium hypochlorite, a decrease in the Langelier index was observed: from -2,23 to -2,08 and from -1,79 to -1,70, which indicates a decrease in its corrosivity. In water untreated with sodium hypochlorite under the influence of the "SeaQuest Liquid" preparation, a slight increase in the Langelier index was observed: from -1,80 to -1,95 and from -1,85 to -2,78, from -2,01 to -2,13, which indicates an increase in its corrosiveness. In the presence of sulphate-reducing and thiobacteria in water, the "SeaQuest Liquid" preparation increases the corrosion rate of steel by 2,9-7,2 times; subject to additional disinfection of water with sodium hypochlorite, it reduces this indicator by 1,4-2,7 times.