Description: Das Projekt "Verbesserung der Entstickung bei biologischer Abwasserklaerung durch Kohlenstoffdosierung aus Klaerschlammhydrolyse" wird vom Umweltbundesamt gefördert und von Universität Karlsruhe, Institut für Siedlungswasserwirtschaft durchgeführt. Primary sedimentation is a widely used process for wastewater treatment. The removal of a significant fraction of the incoming organic load during primary sedimentation results in a load reduction of the subsequent conventional biological treatment and allows for the overall optimization of a treatment plant. However, in the case of biological nutrient removal (BNR) processes the increased requirements in the biological reactors (denitrification and biological phosphorus removal) are in contradiction with primary sedimentation attainments. This contradiction can be resolved by applying anaerobic treatment to the primary sludge in order to produce the necessary additional carbon source through primary sludge hydrolysis. The object of this research is to investigate the influence of sludge hydrolysis processes on the composition and amount of the produced hydrolysate as well as on the quality of hydrolysate as carbon source under varying hydrolysis conditions. Dewaterability studies are also performed to investigate the effect of sludge hydrolysis process on sludge-dewaterability. The optimized conditions of operation will be applied on the wastewater treatment plants in Alexandria, Egypt. This study presents the results of a research involving bench scale experiments related to primary sludge hydrolysis. Temperature, retention time and pH value were the main parameters involved in the design of hydrolysis units. Sodium hydroxide, calcium hydroxide and ferric chloride were the chemicals mainly used for pH adjustment and conditioning of the hydrolysed sludge. Performance is expressed in terms of soluble COD produced as a fraction of sludge total COD. The following main conclusions can be drawn: a) A soluble COD of the order of 15 - 20 percent in terms of sludge TCOD with RT = 6,0 hours at temperature = 35 degrees centigrade at normal pH was achieved. b) At pH = 11, T = 20 degrees centigrade and RT = 6,0 hours, an increase up to 25 - 30 percent soluble COD was obtained. c) A significant soluble COD production of abour 45 percent can be obtained with RT = 6,0 hours, T = 35 degrees centigrade at pH = 11. d) The use of the produced hydrolysate succeeded to improve the denitrification rate up to 9,8 and to 5,7 mg NO3 -N/gVSS.h for biological and chemical biological hydrolysate respectively and to decrease the phosphorus content up to 1,0 mg P/l in the effluent of activated sludge treated wastewater. e) The hydrolysis process has a bad effect on sludge dewatering. In Egypt, the situation is most critical. The Egyptian economy has traditionaly heavily relied on agriculture, as a source for growth, which is almost dependent on surface water for irrigation. Egypt has no effective rainfall except for a narrow band along the nothern coastal areas. The possibility of increasing the fresh water resources from the conventional sources (Nile, rain, groundwater) is doubtful...
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Denitrifikation ? Klärschlammkonditionierung ? Karlsruhe ? Eisenchlorid ? Kabeljau ? Klärschlammbehandlung ? Phosphorgehalt ? Stickstoffelimination ? Biologische Abwasserreinigung ? Belebtschlamm ? Calciumhydroxid ? Hydroxid ? Natriumhydroxid ? Chlorid ? Nitrat ? Nährstoffelimination ? Alexandria ? Biopharmazeutikum ? Abwasserreinigung ? Kohlenstoff ? Vermehrte biologische Phosphorelimination ? Ägypten ? Main ? Biologische Phosphorelimination ? Abwasserbehandlung ? Abwasserbehandlungsanlage ? Aufbereitungstechnik ? Geschiebefracht ? Süßwasser ? Ackerrandstreifen ? Nil ? Gelöster organischer Kohlenstoff ? pH-Wert ? Aufbereitungsanlage ? Studie ? Bewässerung ? Klärschlammentwässerung ? Entstickung ? Laborversuch ? Nassverfahren ? Grundwasser ? Küstenregion ? Abwasser ? Biologische Behandlung ? Hydrolyse ? Oberflächengewässer ? Chemikalien ? Reaktor ? Regen ? Siedlungswasserwirtschaft ? Wasserressourcen ? Landwirtschaft ? Schadensregulierung ? Niederschlag ? Sedimentation ? Schlamm-Hydrolyse ? Kohlenstoffquelle ?
Region: Baden-Württemberg
Bounding box: 9° .. 9° x 48.5° .. 48.5°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1995-12-01 - 1997-12-31
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