Subscribe Now Subscribe Today
Science Alert
FOLLOW US:     Facebook     Twitter
Curve Top
Research Journal of Environmental Toxicology
  Year: 2012 | Volume: 6 | Issue: 5 | Page No.: 198-209
DOI: 10.3923/rjet.2012.198.209
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail
Assessment of Waters Contamination by Nutrients and Heavy Metals in the Ebrie Lagoon (Abidjan, Ivory Coast)
Adama Diarrassouba Tuo, Metongo Bernard Soro, Albert Trokourey and Yobou Bokra

The estuarine part of the Ebrie lagoon, close to the city of Abidjan, is contaminated by several persistent pollutants such as heavy metals, due to discharges from industrial and port wastes, agricultural and urban sewage. Water samples were collected from eighteen stations located in six bays for the analysis of nutrients (NO2¯, NH4+ and PO43¯) and heavy metals (Pb, Cd, Ni, Mn and Zn). Some important limnological parameters were also measured in situ. The samples were analyzed using colorimetric methods and with an Atomic Absorption Spectrophotometer (AAS) for nutrients and heavy metals, respectively. Levels of temperature, pH, salinity and conductivity were ranged save for aquatic life. Mean values of dissolved oxygen and transparency ranged from 1.62±1.62 to 7.26±2.24 mg L-1 and from 0.55±0.43 to 2.36±0.56 m, respectively. According to our data, hypoxia was observed in urban bays, around Abidjan. The analysis of water samples showed NO2¯, NH4+ and PO43¯ levels of mean values 0.152±0.234, 0.857±1.095 and 0.289±0.378 mg L-1 and 0.096±0.128, 0.592±0.758 and 0.295±0.393 mg L-1 in surface and bottom zones respectively. Highest levels for NH4+ and NO2¯ were found in surface waters, while PO43¯ recorded the highest levels in the bottom. For nutrients, significant difference (p<0.05) was observed between locations and seasons. The elemental toxicants Pb, Cd, Ni, Mn and Zn were identified in water of mean values 531.12±128.04, 19.19±12.35, 149.52±59.35, 92.80±22.79 and 19336.25±9960.60 μg L-1, respectively. According to the WHO recommended limits, waters collected at Bingerville, farther from Abidjan, were found to be suitable. Therefore, around Abidjan, apart from Mn, waters analyzed were found contaminated by Pb, Cd, Ni and Zn, with significant difference (p<0.05) between locations for Pb, Cd, Ni and Zn. Apart from Ni (p<0.001), there was no significant difference (p>0.05) between seasons, due to continuous inputs of these pollutants in the lagoon through anthropogenic activities during both seasons.
PDF Fulltext XML References Citation Report Citation
  •    Effects of Oil Pollution on Body Size and Weight of the Sand Lizard Acanthodactylus scutellatus at the Greater Al-Burgan Oil Field in Kuwait
  •    Effect of Sublethal Concentrations of Aqueous Extract of Lepidagathis alopecuroides on Spermatogenesis in the Fresh Water Catfish Clarias gariepinus
  •    Impact of Water Pollution on Histopathological and Electrophoretic Characters of Oreochromis niloticus Fish
  •    Metal Hyperaccumulation in Plants: A Review Focusing on Phytoremediation Technology
How to cite this article:

Adama Diarrassouba Tuo, Metongo Bernard Soro, Albert Trokourey and Yobou Bokra, 2012. Assessment of Waters Contamination by Nutrients and Heavy Metals in the Ebrie Lagoon (Abidjan, Ivory Coast). Research Journal of Environmental Toxicology, 6: 198-209.

DOI: 10.3923/rjet.2012.198.209








Curve Bottom