EVALUATION DE LA CONTAMINATION EN ELEMENTS -TRACES METALLIQUES (MN, CO, CU, PB, HG, NI, ZN)DES EAUX ET SEDIMENTS DE LA RIVIERE YOLO (KINSHASA, RDC)

Abstract

This study aimed to determine the level of selected contaminants (Mn, Co, Cu, Pb, Hg, Ni and Zn) in the water and sediments of the Yolo River which receives effluent from the Limete Industrial District of the Limete area. (Kinshasa, DR Congo). Indeed, in the absence of treatment plants, all urban effluents from neighbourhoods drained by the river and those from industries installed in the neighbourhood are discharged into the collector and the Yolo River, one of the tributaries of the Congo River.The study made it possible to highlight the presence of seven (7) metallic trace elements (Cu, Pb, Fe, Cd, Zn and Hg) in the waters and sediments of the collector of the industrial district and the Yolo River in the city. of Kinshasa, considered problematic, given their toxic nature for living organisms, even at low concentrations of the elements.To do this, collected water samples of the composite type were obtained by mixing three spot samples taken at five stations using a bottle with the neck down at 30 cm depth. In contrast, the sediment samples were hand-collected from 0.5m depth and the resulting composite sediment core was packaged in a clean, labeled 500ml plastic box.All the water and sediment samples were stored in situ at 4°C in the cooler before being sent to the Center for Geological and Mining Research (CRGM) laboratory in Kinshasa for analysis.The physic-chemical parameters (pH, temperature, SS, BOD5) and metallic elements (Mn, Co, Cu, Pb, Hg, Ni and Zn)) were determined in the waters and sediments of the Yolo River. The results showed that the chemical properties were superior to those of the WHO guide standards.