Hidrológiai Közlöny 1977 (57. évfolyam)

2. szám - Dr. Deák Zsuzsanna: Bakteriológiai vizsgálatok a Duna Rajka–Budapest közötti szakaszán

Dr. Deák Zs.: Bakteriológiai vizsgálatok Hidrológiai Közlöny 1977. 2. sz. 83 nyésztettiink ki. A leggyakrabban előforduló szerotípusok a következők voltak: S. agona, S. senftenberg, S. typhi murium, S. infantis, S. worthington és S. derby. Mintaszámra vonatkoztatva a kórokozó előfordulásának gyakorisága 89,9% volt, IRODALOM [ÍJ Módszertani útmutató. A Közegészségügyi-járványügyi Állomások járványügyi bakteriológiai laboratóriumainak egységesített módszerei. Országos Közegészségügyi Intézet, Budapest, 1909. [2] Magyar Szabvány 22901—71. Ivóvíz bakteriológiai vizsgálata. [:i] Standard Methods. American Public Health Association. 13th edition, Njiw York, 1971. [4] Deák Zs.: Különböző Salmonella dúsítási eljárások alkalmazása a higiénés mikrobiológia területén. Egészségtudomány, 14,342 (1970). [5] Kohl W.: Über die Bedeutung bakteriologischer Untersuchungen für die Beurteilung von Fliessgewässern, dargestellt am Beispiel der Österreichischen Donau. Arch. Hydrobiol./Suppl. 44, 4, 392 (1975). [6 ] Daubner /., Tréilova B.: Ergebnisse der mikrobiologischen Donauforschung in einem Punktprofil. Biologia (Bratislava), 28, 9, 775 (1973). [7] Némedi I/., Hegedűs J.-né: Felszíni vízkivétellel termelt víz bakteriológiai vizsgálatának néhány kérdése, különös tekintettel az anaerob és aerob spórás baktériumok előfordulására. Budapesti Közegészségügy, 1, 12 (1973). [8] Egységes vízminőségi kritériumok és normák, valamint osztályozásuk elve. OVH, Budapest, 1—18, 1964. [9] Deák Zs., Pénzes M.: A Duna egyes szakaszainak vízbakteriológiai jellemzése, különös tekintettel a szabad strandok higiénés megítélésére. Egészségtudomány, 17, 336 (1973). Bacteriological analyses over the Kajka — Budapest Danube section By dr. Zs. Deák (Miss ) Under the UNDP/WHO Project "Water quality Control l'ilot Zones" bacteriological analyses have been performed at 11 sampling stations on the Danube between Rajka (R. St. 1848 km) and Budapest (R. St. 1654 km) with the aim of determining the extent and variations of faecal- and other pollution along this section. The quantitative analyses on the 336 water samples taken between June 1973 and December, 1975 included the determination of the following parameters: Coliform- (37 deg. C), faecal coliform- (44.5 dog. C) bacteria, faecal streptococci, heterotrophic mesophilic bacteria (37 deg. C) and psychrophilic bacteria (20 deg. C), as well as sulphite reducing spore-forming, anaerobic Clostridia. The tests for bacteriophages wore semiquantitative, while for the bacteria belonging to the Salmonella group qualitative methods were used, except for the upstream- and downstream ends of the section, where quantitative analyses were performed. Under the impact of the untreated effluents of the two largo towns Vienna and Bratislava situated upstream of the entrance cross-section (R. St. 1848 km) the Danube is polluted, as demonstrated by the counts of the indicator bacteria (coliform: 237/ml, faecal coliform: 70/ml, faecal streptococci: 30/ml, Clostridium: 2/ml, mesophilie: 959/ml, psychrophilic 0200/ml), as well as by the tests on bacteriophages and Salmonellae. The river, which changes over the section from mountain- to lowland character, has a high assimilative capacity and at R. St. 1800 km the pollution measured in terms of bacteriological parameters has decreased substantially. Over the section studied, the Danube receives the waters of 4 tributaries. The pollution discharged by these produces characteristic peaks on the profile curves of the individual parameters, the magnitude of which depends on the precipitation volumes varying from year to year, as well as on the streamflow rate. Over the section from R. St. 1694 km to R. St. 1654 km there is no tributary . The values of the individual indices tend to decrease gradually, but at R. St. 1659 km a rise in the level of pollution was observable, probably as a consequence of more intensive bottom silt formation and of local polluting discharges. In wet years a considerable increase in the count of Clostridium bacteria was observed in this area, which has impaired also the quality of drinking water at Budapest supplied by the Surface Water Works. Between Rajka and Budapest the counts of faecal indicator bacteria determined from unit volume of river water have decreased by 80 per cent on the average. The decrease in the counts of mesophilie- and psychrophilic bacteria was 48 and 70%, respectively , whereas the phag-counts decreased by 20 per cent only. The Clostridium count increased along the section. e Over the Austrian- and Slovakian sections of th Danube the bacterial pollution has been observed to increase appreciably during the sugar refining season (September to November). Over the upper half of the Rajka

—Budapest section the effect of sugar refinery effluents appeared with gradually decreasing intensity and was detectable by the higher counts of coliform-, mesophilie- and psychrophilic bacteria, Although the level of pollution has decreased slightly over the three years of study, the Danube water remained still too highly polluted bacterially to be suited for bathing, and owing to the need of removing the more resistent micro-organisins, the treatment to drinking quality is also more costly. Pathogenic bacteria belonging to the Salmonella group were detected in 89.9 per cent of the samples. In the 336 water samples altogether 807 Salmonella strains were isolated. The serotypes most frequently encountered included S. agona, S. senftenberg, S. typhi murium, S. infantis, S. worthington and S. derby. According to the annual averages of the quantitative Salmonella analyses performed with an informative character the counts of Salmonella bacteria per litre of Danube water were 22 to 51 at Rajka and 26 to 109 at Budapest. The peak values (150 to 390/litre) were observed in September-October, less frequently in MayJune periods.