Pages: (1-14 )
Abstract
Geochemical survey of the coastal water bordering Ijede town of Lagos Lagoon in Ikorodu, Lagos, Nigeria was carried out to assess the effect of the cooling activities of the thermal power station on the geochemical characteristics of the ecosystem. Water and bottom sediments samples were collected from six (6) different stations, perpendicular to the shoreline for geological and chemical analyses. Granulometric analysis gave an insight to the grain size which is an indication of the overall competence of the transport dynamic system. The water-sample were analyzed for pH, conductivity , turbidity, salinity, alkalinity ,dissolved oxygen, total suspended solid, temperature and total dissolved solid. The hydrogen ion concentration (pH) range recorded in the study stations is lightly basic. The values range between 7.99 and 7.80. The highest turbidity value of 21 was recorded at station 4, while the lowest value of turbidity recorded was -3 at station 6. Dissolved Oxygen (DO) for the study stations ranged from 5.20mg/l to 8.00mg/l. The temperature of the study area (within the 3m depth) range from 33oC to 38oC, with the mean value of 35.42oC. This value was consistent through out the depth of the study area, which was considered to be too high for a natural ecosystem according to WHO standard for brackish water. The reason for the high temperature recorded may be due to the cooling activity of the power station. Sediments distribution ranged from very fine to medium grained, poorly sorted coarsely skewed with a leptokurtic distribution. This is an indication of short distance of transportation or rapid sedimentation and possible weak alongshore current.
Keywords: leptokurtic skewness, geochemical, thermal, temperature, conductivity,