bbk 000000
UDC 628.166.085
Kostyuchenko S. V., Koudryavtsev N. N., Svitnev S. A., Timakov S. V., Ustiuzhaninov A. M., Shcheglov A. Iu.
Biotesting – the modern criterion of evaluating the efficiency of UV-systems for water disinfection
Summary
Nowadays ultraviolet irradiation increasingly becomes an actual method of water disinfection. Herewith units with amalgam and mercury low pressure lamps are mostly used. In the radiation spectrum of these lamps the mercury resonance line is dominating with 253.7 nm wave length on which up to 40% of the lamp power can fall. Radiation with this wave length has a powerful disinfection effect. The impact of UV-irradiation results in irreversible DNA and RNA damage in microorganisms so that the latter lose their reproductive capacity (become inactivated). The main parameter that characterizes the efficiency of these installations is UV-irradiation dose. It is a calculated value, therefore to obtain the maximum information on the operation of a UV-disinfection unit it is advisable to carry out biotesting with the help of live microorganisms. Besides, in some countries (Germany, France, Austria, USA) biotesting of UV-systems is obligatory. In Russia bio-validation is not obligatory; therefore real biological tests are often substituted with computer simulation. Process simulation carried out for a seven-lamp unit manufactured by «LIT» Scientific-Production Association produces the results close to the results obtained during biotesting. This confirms the range of use of disinfection UV-unit claimed by the manufacturer. However, the absolute guarantee of the UV-unit efficiency is bio-validation only since it supposes the use of live water and microorganisms. The data obtained in the process of biotesting allow describing the specific features of the disinfection unit operation to the fullest extent possible. The certificate verifying biotesting is a credible guarantee that the unit will provide for the required level of water disinfection.
Key words
microorganisms , inactivation , biotesting , amalgam lamp , ultraviolet irradiation , UV disinfection , UV-unit , irradiation dose
|
bbk 000000
UDC 628.1.03
Ponomarev A. P.
Aqueous extract of shungite mineral – a complexing agent
for microorganisms in aqueous solution purification
Summary
The presence of microbiological pollution has been one of the most important factors that determine drinking water quality. Among the variety of water purification technologies unique mineral – shungite that contains carbon in active form – fullerene has been widely used over recent years. Herewith the strengths of shungite including bactericidal one are associated with fullerenes in particular. It is known that fullerenes merge into water in minimum concentrations; whereas for their efficient extraction organic solvents are needed. The results of studies of the effect of aqueous shungite extract containing beside macro- and microelements ultramicroelements – lanthanoids on microorganisms in aqueous solutions with the purpose of disinfection are presented. Electron microscopic studies provided for determining dual character of the effect: complex formation of microorganism cells and evident signs of bacterial cell destruction. Microorganisms as part of aqueous complexes are removed by sedimentation, centrifuging or microfiltration. Through the example of nanobacteria and foot-and-mouth disease viruses and virions the process of complex formation shall be considered as concentration with possible further use of the given microorganisms for scientific studies. The main mechanism of complex formation is the presence of high-reactive lanthanoid cations that are trivalent positive under normal conditions in shungite aqueous solution. The phenomenon of selective coagulation of bacterial cells is due to the reaction of lanthanoid cation complex formation with nucleic acids of microorganisms. It is assumed that the reaction of nucleic acid with metals is carried out by phosphate groups.
Key words
microorganisms , complexing , lanthanoids , electron microscopy , shungite , aqueous solution
|
bbk 000000
UDC 628.16/.31.085
Rudnikova G. I., Zelenin A. M.
Water Disinfection Using the UV-Irradiation at Water Treatment Facilities of the City of Angarsk
Summary
For the purpose of improving the barrier function with respect to viruses, parasites and water bacteria at water treatment facilities of Angarsk the station of potable water UV-disinfection was put into operation in 2009. The station’s equipment is located in the building of main facilities block before the vertical mixers. From the first days of operation the high efficiency of the UV-disinfection method was established. The analyses results show the complete inactivation of all water microorganisms and dependence of intensity of lamps radiation on physicochemical properties of river water as well. For the purpose of eliminating this dependence the alternative scheme of water feed is offered: treated water after the filter is delivered to UV-disinfection plants instead of river water.
Key words
potable water , chlorination , turbidity , ultra-violet disinfecting , water treatment , microorganisms , inactivation
|
bbk 000000
UDC 543.39
Bogatyreva I. A., Artemova T. Z.
Accelerated Method of Control of Membrane Filters for Bacteriological Analysis of Water
Summary
An accelerated algorithm of control over membrane filters used for rating of water quality according to microbacteriological characteristics has been developed. A preliminary stage of rearing of model microorganisms is excluded from the accelerated method. The control is exercised over two strains of model microorganisms differing in size and shape of cells. The developed algorithm is also used for rating of quality of track membrane made of polyethylene terephthalate. In the process, the percentage of removal of model microorganisms with track membrane is over 80% and meets the requirements of the International standard ISO 7704-85.
Key words
microbiology , water quality , control , membrane filter , microorganisms , analysis
|
bbk 000000
UDC 628.336.1:54:57
Shchetinin A. I.
Elemental Composition of Activated Sludge
Summary
A review of literary data on elemental composition of activated sludge components generated in the course of wastewater biological treatment is presented. Empiric formulas of activated sludge organic matter, organic matter of different microorganisms, RNA and DNA, carbohydrates, fats, fulvic acids and humic acids are considered. On the basis of literary data on seven cellular components for Escherichia coli cells the empiric formula has been obtained; this formula is proposed for biomasses of all microorganisms of activated sludge. A ratio ThOD : VSS = 1,42 coinciding with the known values; for cellular substance COD : N : P = 50 : 5 : 1, which is close to the known BCOD : N : P = 100 : 5 : 1. for the initial substrate is typical for this elemental composition. Components described make it possible to determine the elemental composition of extracellular substances of activated sludge.
Key words
microorganisms , activated sludge , wastewater biological treatment , elemental composition , proteins , nucleic acids
|
|
