Analysis of Сauses of Colmatage and Corrosion of Water-Intake Well Equipment under Conditions of Increased Anthropogenic Load

Summary

In the course of operation of water intakes from underground sources the problems associated with the processes of fouling and corrosion of the metal equipment of artesian wells inevitably increase. The intensity of deposit formation and corrosion development on the well equipment depends on the well output, the chemical composition of ground water, the presence of methane-producing and other bacteria generating an extremely active corrosion medium. Monitoring of the chemical composition and microbiological analysis of ground water make it possible to identify the causes of colmatage and corrosion of metal-containing elements of the wells under the conditions of the increased anthropogenic load, which further facilitates the selection of methods of struggle against these phenomena.

Key words

monitoring , ground water , artesian well , colmatage , corrosion , anthropogenic load , bacteria , microbiological analysis

Bioaerosols at wastewater treatment facilities: sources, composition, sanitary and epidemiological risks (a review)

Summary

Attention to the issue of bioaerosol emissions in the process of wastewater treatment has increased with reports about wastewater aerosolization as a potential source of SARS-CoV-2 virus exposure to the air during the recent COVID-19 pandemic; however, the impact of exposure to bioaerosols on the health of the people with compromised immunity, personnel of treatment facilities and population of adjacent territories has been reported earlier. Emission of bioaerosols occurs at various stages of the technological process (mechanical treatment, biological treatment, wastewater sludge treatment). The amount of bioaerosols formed depends on the hydrodynamic conditions of wastewater treatment, type of treatment plant (closed or open), wastewater composition, treatment technology used, technical characteristics of the equipment, capacity of the treatment facilities, operating conditions, aeration rate and mode, concentration of biomass and growth phase of microorganisms. Bioaerosols contain pathogenic bacteria including those resistant to antibiotics, fungi that are potential pathogens of mycetogenic diseases, as well as viruses that can survive for a long period of time in wastewater and are spread by airborne transmission. The applied methods of bioaerosol analysis provide data on the presence, size and viability of aerosol microorganisms; however, until now no standard methodology for sampling bioaerosols has been available. Thermal treatment and ultraviolet irradiation, the use of air filters and ventilation have become widespread among the means of preventing the formation and spread of bioaerosols. Various research in this area has focused on the use of granular activated carbon, floating plastic balls for water surface isolation, reactor surface vacuum treatment, wastewater sludge composting using membrane coating, the use of biofilters, and installation of wind barriers along the boundaries of wastewater treatment facilities and vertical gardening systems.

Key words

wastewater , viruses , bacteria , treatment facilities , bioaerosols , fungi

The use of aqueous extract of shungite mineral for the removal
of bacterial flora from water

Summary

Safe and high quality drinking water is the most important factor that is effecting the human health, rise in births, reduction of mortality, increased expectation of life. The objective of the present work was model developing of the method of removing bacterial flora from water with the use of shungite, unique natural mineral. The key point of using this mineral for water purification is in using crushed shungite not as a feed but for the production of aqueous extract of minerals. In the process of adding refined and concentrated shungite extract into drinking or other water the effect of active complexing of its organic component was defined. The process of extracting minerals from crushed shungite will be most efficient in acidic aqueous media with pH 2–2.5; herewith macro- and microelements and rare-earth ultramicroelements – lanthanoids pass into water. To concentrate the extracted minerals water was evaporated by regular boiling to 1/10 of the original volume with pH 2–2.5. Removal macro- and microelements from extract with preserving lanthanoids was carried out in the process of de-acidification with sodium hydroxide solution with subsequent extract clarification by centrifuging. Addition of 1% shungite extract into raw water is accompanied by the formation of organic suspension that is removed during filtration, sedimentation or centrifuging. At that the mineral composition of water does not essentially change. The mechanism of removing bacterial flora from water is conditioned by the physical and chemical interaction of high-reactive cations of lanthanoids (+3 valence) with bacterial cells initiating their complexing. The phenomenon of selective coagulation of bacterial cells is caused by the reaction of lanthanoid cations complexing with nucleic acids of microorganisms. It is expected that the reaction of nucleic acid with metal is performed by phosphate groups.

Key words

membrane filter , bacteria , shungite mineral , aqueous extract , lanthanoids , de-acidification