International Journal of Research in Environmental Studies
ISSN: 2059-1977
Vol. 8(3), pp. 36-47, July 2021
doi.org/10.33500/ijres.2021.08.004

Seasonal and spatial variation of trace elements (Cd, Pb, Ni, Cu, Cr, As and Hg) in the waters of the Lake Nangbéto in Togo

Koudjo Adje^1,2, Hodabalo Dheoulaba Solitoke^1,2*, Kamilou Ouro-Sama^1,2, Gnon Tanouayi^1,2, Tchaa Esso-Essinam Badassan^1,2, Housseni Ahoudi^1,2, AkoétêYaovi Nyametso^1,2 and Kissao Gnandi^1,2

¹Université de Lomé, Faculté des Sciences, Laboratoire de Gestion, Traitement et valorisation des déchets, BP. 1515, Lomé -Togo.
²Université de Lomé, Faculté des Sciences, Département de Géoscience et Environnement, 1515, Lomé -Togo.

*To whom correspondence should be addressed. E-mail: dominiquesolitoke@yahoo.fr.

Received 26 March, 2021; Received in revised form 10 May, 2021; Accepted 14 May, 2021.

Abstract

Keywords:
Lake Nangbéto, Trace elements, Water, Contamination, Togo.

Developing countries are encountering many difficulties to cope with water supply and sanitation. In these countries, not only that there is insufficient drinking water infrastructure but also poverty and ignorance push people to use surface waters (lake and river water) for their daily needs. The Lake Nangbéto was built in 1987 on the Stream of Mono River for hydroelectricity production. Today, the watershed of Mono River faces numerous environmental problems including soil and water pollution with trace elements, as well as pesticide residues and hydrocarbons. The aim of the study was to analyze trace elements (Cd, Pb, Ni, Cu, Cr As and Hg) in the waters from Lake Nangbéto and its surroundings in order to assess their quality. Water samples were collected in polyethylene bottles and were acidified to 1% with nitric acid. The trace elements were determined by Atomic Absorption Spectrometry. From the results obtained, the waters of Lake Nangbéto and its surroundings are contaminated for all seasons, especially by cadmium, lead and mercury; with average concentration of 9.21 and 6.80 µg/L for cadmium, 14.38 and 42.53 µg/L for lead; respectively in the rainy season and dry season and 8.04 µg/L for mercury in the dry season. The pollution factors for cadmium were 3.07 times and 2.27 times the World Health Organization (WHO) standard, 1.44 and 4.25 times for lead; respectively in the rainy season and dry season and 1.34 times for mercury in the dry season. The other elements analyzed showed low concentrations compared to the standards set by the WHO for drinking water.