Extraneous water that inflow to the sewage system is basically divided into two streams—accidental water (mainly rainwater) and infiltration water
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The aim of the research was to assess the amount ...of extraneous water inflow to the considered system. Five different quantitative approaches were applied. Three well-known methods were used: the triangle method, the minimum night flow method, and the moving minimum method. The annual balance of water consumption and sewage supply to the wastewater treatment plant were calculated. Also, some analysis of sewage discharge during wet and dry weather was carried out. The study covered data from 6 years from 2014 to 2019. It was established that the main source of extraneous water was infiltration, because three methods which concern both streams (triangle method, minimum night flow, variability in wet and dry weather) confirm the conclusion. Merely the moving minimum method results differ from the others. In this investigation, accidental water (basically rainwater inflow) poses a significantly less share in the total volume of sewage compared to infiltration water. The total amount of extraneous water was estimated as in the range from 38 to 53% of annual sewage supply to wastewater treatment plant, depending on the year. Share of infiltration and accidental water is changing in different methods. Share of infiltration was in a range between 18 and 68%, depending on the year and the method used. Share of accidental water was in a range between 7 and 22%.
Abstract
Informal housing, and operational and management deficiencies, influence sewerage system performance in Brazil. Inadequate sewage volumes in storm sewers lead to fecal contamination and ...affect recreational water environments. As overflow structures, dry-weather sewage intakes (DWSIs) are used to intercept and transfer sewage from storm- to sewage- sewers. For cities without public services, the DWSI strategy has been suggested as an option to enable easier and more rapid responses in terms of sewage pollution control. The strategy may also lead to gradual construction of a separate sewerage system in a two-step plan: initially, based on the construction of DWSIs and wastewater treatment plants, and then, on the construction of separate sewers. The paper is a discussion of the main technical challenges in sustainability of the DWSI strategy, and includes a case study of slum and other informal housing areas in Rio de Janeiro.
As part of a research & development project commissioned by the Land of North Rhine-Westphalia's Ministry for the Environment and Nature Conservation, Agriculture and Consumer Protection (MUNLV) an ...examination is being carried out of the general possibilities for centralised and decentralised treatment storm water runoff to be discharged into (canalised) receiving waters and the costs ensuing from this. The examination of the different options is being carried out under real conditions, with the Briller Creek (Wuppertal/Germany) and Müggen Creek (Remscheid/Germany) catchment areas being used as models. The range of investigations deals with a comparison between 'decentralised, semicentralised, centralised' storm water treatment, centralised storm water treatment involving a separate sewer and parameter-specific pollution based storm water runoff control. In the framework of the research project each of the variants is to be elaborated and the costs are to be calculated so as to permit a comparison between the different system designs. In particular, the investigations are to take into account the actual requirements to be met by storm water drainage systems involving separate sewage systems.
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