Hidrológiai Közlöny 1971 (51. évfolyam)
4. szám - Dr. Benedek Pál: Tervezési irányelvek módosítása az eleveniszapos szennyvíztisztításnál (II. rész)
Dr. Benedek P.: Tervezési irányelvek Hidrológiai Közlöny 1971. 4. sz. 165 [54] Starosolszky Ö.: A folyadék-, hő- és anyagmozgatás összefüggései. Beszámoló norvégiai tanulmányútról. VITUKI-jelentés. 1969. [55] Tasfi L. — Benedek P.: Teljesoxidációs szennyvíztisztító kisberendezések kialakítása. VITUKI-jelentés. 1967. [56] Tóth A.: Szennyvizek magasfokú tisztításának korszerű módszerei. Vízügyi Közlemények (Nyomdában.) [57] Vágás I.: Az ülepítés fiziko-kémiai szemlélete. Hidrológiai Közlöny. 5. sz. 1960. [58] Zeper, J. és Man A. de: New developments in the design of activated sludge tank with low BOD loadings. 5 t h Conf. IAWPR. San Francisco. 1970. [59] Wuhramnn, K.: Nitrogén removal in sewage treatment processes. Verli. Int. Ver. Limnol. 15. 1964. [60] Wulirmann, K.: Hauptwirkungen und Wechselwirkungen einiger Betriebsparameter. Schweiz. Z. Hydrol. 27. 2. sz. 1965. [61] Wuhrmann, K.: Szóbeli közlés, 1970. The Modificatiou of Design Criteria for Wastes Treatment by the Activated Sludge Method By Dr. Benedek, P. Candidate of Technical Sciences Af'tera careful analysis of experiences gained both at home and abroad, as well as of experimentál and research results obtained during the pást 10 years a revision of the design criteria for wastes treatment by the activated sludge method is suggested. It has been concluded that a) the biological treatment of increasing volumes of industrial wastewaters must be solved individually, h) the quality composition of domestic wastes underwent considerable changes, with increasing motorization, the growing popularity of synthetic detergents and with increasing volumes of industrial and trade wastes being discharged into the municipal se were, the quantity of organic substances difficult to remove shows an increasing trend, e) deteriorating water qualities in the recipients eall on the one hand for the high-efficiency removal of organic substances, on the other for the removal of nitrogén compunds as well, consequently the nitrification must be performed in the activated sludge plánt itself, d) the problem of temperature dependence is being made more acute by the relatively low temperature of certain industrial wastes, as well as by the nitrification requirement mentioned in the preceding paragraph, e) the efficiency of secondary settling tanks is impaired by maintaining the concentration of the suspended content of activated sludge at figures higher than 4 to 5 kg/cu. m, while the specific bacteria count in the sludge is reduced, f) the requirement of maintaining the output of the secondary settling tanks, i.e., the suspended content of the effluent at the desired level oalls for the revision of dimensioning procedures for secondary settling tanks, g) the specific costs of areating basins equippecl with new-type verticai shaft turbines are appreciably lower than those of earlier designs, ari areation volume of 1500 to 2000 cu. m can be served by a single turbine, while no more than the observation of a min. I : 4 depth : width ratio is necessary. On the strength of the above considerations the following modifications of the design criteria are suggested: 1. The of time residenee in the aerating basin should be inereased appreciably, as indicated by the formula 5b, using the rate eonstant v* of specific organic removal and organic concentration X 1 obtained from Table I. These values include alsó the demand for nitrification, ensured alsó at winter temperatures. 2. Oxygenation is required to compensate the oxygen consumption due not only to organic removal and the endogeneous aspiration of activated sludge, but alsó to nitrification, as indicated by Eq. (21), whereby the earlier OC/Tfc ratio is raised substantially. 3. In computing the growth of excess sludge the inactive organic-substance content of raw water must be taken into consideration more accurately according to Eq. (22). In this way greater sludge volumes and higher proportions of organic substances are obtained. 4. Secondary settling tanks should be dimensioned for suspended matter loading, on the basis of Eq. (23) and the curves in Fig. 5. It should be emphasised in conclusion that the Constanta involved in the above design formulas of activated sludge treatment depend on the composition of the incoming wastes, and their particular magnitude should be determined by experiments. The relevant experimentál method has been developed and published in recent years by the Research Institute for Water llesources Development, so that by now reliable design criteria can be furnished in a brief time and at little expense for individual industrial wastes treatment installations.
