Vízügyi Közlemények, 1973 (55. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(39) Water management and the related economics - also known as hydroeconomics — form thus a new branch of science developing on the boundary of natural science, engineering and economics. The subject is thus a synthesis of the common elements which promote in the fields of engineering hydrology, hydrotechnics and political economics the coordination of natural conditions and social demands in water management. The activities in water management are extremely diversified, as shown by the grouping according to special divisions in Fig. 7. The position of water management within llie sectorial system of economy is illustrated in Fig. 2. This grouping, however, serves only as an auxiliary device of methodology without affecting the uniform, comprehensive system of water management. WATER QUALITY CRITERIA FOR SPECIFYING THE OPERATING EFFICIENCY OF TREATMENT PLANTS CONTEMPLATED AT BUDAPEST By Benedek, Pál, Hock, Béla, dr. Kádár, László, Puskás, Mária and Rymorz, Pál (For the Hungarian text see pp. 167) The objective of the present paper is to establish the necessary efficiency criteria for the wastewater treatment plants presently in the design stage for the capital Budapest. After the collection, analysis and evaluation of the necessary data the following conclusions have been arrived at: a) As to be seen from Table I, the organic pollution present in the Danube at its entrance at Rajka into the country increases at the average rate of round 5% annually. Considerable organic pollution is discharged by the tributaries entering from Czechoslovakia ( Table II, Fig. 1 ), so that the wastewater load discharged at Budapest cannot be assimilated by the river down to the southern border. The concentration of oxygen consuming organic substances (BOD

5, chemical oxygen demand) is greater in the outflow section than at the entrance ( Figs. 1, 2}, allhough regarded on the whole the BOD

5 and the COD values hardly exceed over the Hungarian reach of the Danube the limit value specified for the first water quality class. b) Concerning the specific pollutants (ammonia, phenoles, petroleum derivatives, detergents), the water in the Danube at the entrance cross-section can be classified into the second quality class only, the concentration of phenoles being even higher by one order of magnitude than the limit value of the first quality class. Over the Hungarian reach the concentration of the aforementioned components decreases positively in spite of the wastewaters discharged at Budapest ( Figs. 3 and 4) and in this respect the water passing to our southern neighbour is of a quality superior to that received. с J In the above assessment of water quality no attempt has been made at completeness, since the series of data available are incomplete for the present purpose, owing to the position of sampling points along the lenght and within the crosssections, to the frequency of sampling, to the inhoyiogeneity of sampling and analytical methods, further because of the lack of analyses on specific pollutants. d) In view of the fact that the water resources represented by the Danube are definitely international in character and further that it is the most important future source of both domestic and industrial supply to some of the countries — especially Hungary —, it is essential that each component should comply with the first class requirements, as indicated in Table III. In the future each Danube country should be obliged to pass water received as of first class quality in the same condition to its donwnstream neighbour, and should thus be allowed to utilize only the assimilating capacity of its own Danube reach for the disposal of wastewaters. The necessary degree and efficiency of wastewater treatment is practically controlled by this condition and this has been adopted as the starting basis in the present computations. e) It has been estimated, that adequate (but not complete) mixing of the wastewaters of Budapest, if these were discharged at a single point, would occur over a lenght of 50 to 70 km only ( Fig. 6) When discharging at two points, the mixing lenght is reduced by three-quarters, so that the study of mixing conditions is impor-