Proposing a new strategy to minimize domestic wastewater under the influence of human factor in Antananarivo, Madagascar

Abstract

Water pollution happens when organic or inorganic materials, even solid materials are poured into the water which degrades its physicochemical quality. The purpose of this study is, to identify, to describe and to highlight the major source of wastewater, and proposing a new strategy for minimization in Antananarivo, Madagascar. Antananarivo is one of the dirtiest cities on the African continent according to the classification made by Forbes magazine and Afrikmag. To know the current situation, an in-situ analysis of the physical parameters: colour, odour, turbidity and electrical conductivity using the turbidimeter and the conductometer are measurable parameters in the field. Major elements analyses, BOD5 using Oxytop method analysis, COD using Potassium dichromate, suspended solids using membrane filtration are measured in the laboratory. The turbidity of the discharges fluctuates from 127 NTU to 421 NTU). For electrical conductivity, it varies from 217 to 977μS.cm−1, BOD5 is of the order 3 to 88mg.L−1, while COD diverges from 279mg.L−1 to 730mg.L−1 and suspended matter oscillates from 400mg.L−1 to 60mg.L−1. Some parameters and concentrations exceeded the discharge standard Malagasy and the international Standard. The best solution for the management of water quality in the face of domestic pollution is the treatment of wastewater before discharge into receiving environments and the sensibilization of the population to take their responsibility.