Concentrations of heavy metals in raw wastewaters of Cotonou city (Benin)

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Research Paper 01/08/2014
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Concentrations of heavy metals in raw wastewaters of Cotonou city (Benin)

Dogbè Clément Adjahouinou, Emile Didier Fiogbé
J. Bio. Env. Sci.5( 2), 534-541, August 2014.
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The current study aims to determine the concentration of heavy metals in raw wastewaters of Cotonou. Waters of three main sewers dumping their contents in Cotonou lagoon have been bimonthly sampled at their discharge point. Heavy metals analysis were carried out by colorimetric methods using molecular absorption spectrophotometer HACH DR 2800 for iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mn), aluminium (Al), cadmium (Cd) and lead (Pb) and by Wagtech Digital Arsenator Wag-WEI 0500 for Arsenic (As). Total mean heavy metals concentration registered in effluents were 0.269; 0.951; 0.340; 0.064; 0.270; 0.035; 0.024; 0.730 and 1.776 mg/L respectively for Fe, Zn, Cu, Cr, Mn, Al, As, Cd and Pb. These heavy metals mean concentrations were generally found to be within Beninese standards as well as Moroccan and Egyptian acceptable limits for direct discharge with exception of Cd and Pb mean concentrations which exceeded these standards. Raw effluents drained by open main sewers are thereby contaminated by many toxic heavy metals and constitute a threat for lagoon ecosystem and consequently humans who are halieutic products consumers. It is hence necessary to undertake their purification including heavy metals removal before pouring it in aquatic environment.


Adam KS, Boko M. 1993. Le Bénin. Les Editions du Flamboyant / EDICEF.Vanves, Cedex. 96.

Akpor OB, Muchie M. 2010. Remediation of heavy metals in drinking water and wastewater treatment systems: Processes and applications. International Journal of the Physical Sciences 5, 1807-1817.

APHA (American Public Health Association), AWWA (American Water Works Association), WEF (Water Environment Federation). 2012. Standard methods: for the examination of water and wastewater. 22nd edition. Shington, USA, 1360.

Biney C, Amuzu AT, Calamari D, Kaba N, Mbome IL, Naeve H, Ochumba O, Osibanjo O, Radegonde V, Saad MAH. 1994. Review of heavy metals. In: Calamari D, Naeve H, ed. Review of pollution in the African aquatic environment. CIFA Technical Paper N°25. Rome FAO, 118.

Chebbo G, Gromaire MC, Ahyerre M, Garnaud S. 2001. Production and transport of urban wet weather pollution in combined sewer systems: the «Marais» experimental urban catchment in Paris. Urban Water 3, 3-15.

Daifullah AAM, Elewa AA, Shehata MB, Abdo MH. 2003. Evaluation of some heavy metals in water, sediment and fish samples from River Nile (Kafr El-Zyat city), Egypt: A Treatment approach. African Journal of Environment assessment and management 6, 16-31.

Edorh P. 2007. Heavy metal action. TWAS newsletter 19, 4.

EEAA (Egyptian Environmental Affairs Agency). 1994. Law number 4 of 1994 promulgating the environmental law and its executive regulation, Egypt.

Ellis JB, Harrop DC, Revitt DM. 1986. Hydrological controls of pollution removal from highway surfaces. Water Research 20, 589-595.

Fernandez M, Cuesta S, Jimene O, Garcia MA, Hernandez LM, Marina ML, Gonzalez MJ. 2000. Organochlorine and heavy metal residues in the water/sediment system of the Southeast Regional Park in Madrid, Spain. Chemosphere 41, 801-812.

HACH. 2004. DR/890 Datalogging colorimeter handbook. Hach company world headquarters, Loveland, Colorado, 616.

Hammi H. 2010. La pollution des eaux par les métaux lourds. Présentation aux IIIème Olympiades Tunisiennes de Chimie 2010, 31.

Harati M, Pour MV, Rastegar MT, Foghi B. 2011. Effect of urban wastewater usage and problems of accumulation of heavy metals in agricultural lands (south of Tehran). African Journal of Agricultural Research 6, 3224-3231.

Kaiser J. 2001. Bioindicators and Biomarkers of Environmental Pollution and Risk Assessment. Enfield, NH, Science Publishers, 204.

Klavins M, Rodinov V, Vereskuns G. 1998. Metals and organochlorine compounds in fish from Latvian Lakes. Bulletin of Environmental Contamination and Toxicology 60, 538-545.

Lagerweff JV, Specht AW. 1970. Contamination of roadside soil and vegetation with Cd, Ni, Pb and Zn. Environmental Science and Technology 5, 483-586.

Liu C, Bai R, Ly QS. 2008. Selective removal of copper and lead ions by diethylenetriamine-functionalized adsorbent: Behaviors and mechanisms. Water Research 42, 1511-1522.

MATEE   (Ministère    de    l’Aménagement,   du Territoire, de l’Eau et de l’Environnement)/Maroc. 2005. Décret n° 2-04-553 du 24 janvier 2005 relatif aux déversements, écoulements, rejets, dépôts directs ou indirects dans les eaux superficielles ou souterraines.

MEHU (Ministère de l’Environnement de l’Habitat et de l’Urbanisme)/Bénin. 2001. Décret N°2001-109 de 4 avril 2001 fixant les normes de qualité des eaux résiduaires en République du Bénin, 27.

Mohamed  AH,  Lamiaa  IM,  Mohamed  AES. 2012. Physiochemical analysis and speciation of heavy metals in wastewater and sediment samples from the Suez province in Egypt. Journal of Environmental Chemistry and Ecotoxicology 4, 222-228.

Mojiri A. 2012. Phytoremediation of heavy metals from municipal wastewater by Typhadomingensis. African Journal of Microbiology Research 6, 846-850.

Oguzie FA, Okhagbuzo GA. 2010. Concentrations of heavy metals in effluent discharges downstream of Ikpoba river in Benin City, Nigeria. African Journal of Biotechnology 9, 319-325.

Scherrer B. 2007. Biostatistique, Volume 1. Gaëtan Morin Ed., Boucherville, 816.

Singh D, Gupta R, Tiwari A. 2011. Phytoremediation of Lead from Wastewater Using Aquatic Plants. International Journal of Biomedical Research 7, 411-421.

Van Metre PC, Mahler BJ. 2003. The contribution of particles washed from rooftops to contaminant loading to urban streams. Chemosphere 52, 1727-1741.

Vissin EW, Sintondji LO, Houssou SC. 2010. Etude de la pollution des eaux et de la contamination du Tilapia guineensis du canal de Cotonou par le plomb. Revue de Géographie du Laboratoire Leïd 8, 215-229.

Yèhouénou EAP, Adamou R, Azéhoun PJ, Edorh PA, Ahoyo T. 2013. Monitoring of Heavy Metals in the complex “Nokoué lake – Cotonou and Porto-Novo lagoon” ecosystem during three years in the Republic of Benin. Research Journal of Chemical Sciences 3, 12-18.

Yong  RN,  Mohamed  AMO,  Warkentin  BP. 1992. Principles of contaminant transport in soils. Developments in Geotechnical Engineering, 73. Elservier Science Publishers, B.V. Amsterdam. The Netherlands, 327.

Youssao A, Soclo HH, Bonou C, Vianou K, Gbaguidi M, Dovonon L. 2011. Evaluation de la contamination de la faune ichthyenne dans le complexe lagunaire Nokoué-chenal de Cotonou par le plomb : cas des espèces Sarotherodon melanotheron, Tilapia guineensis et Hemichromis fasciatus (Bénin). International Journal of Biological and Chemical Sciences 5, 595-602.