Tag Archives: Sediment

Sediment Yield on Different Agricultural Land use Types in Ikpoba Okha, Nigeria (Published)

This work is an assessment of variations in the rate of sediment yield from different agricultural landuse types in Ikpoba Okha. The research design adopted in this study was based largely on direct field measurement. To generate the data required to accomplish the philosophy of this work, measurement of rainfall amount (mm), rainfall intensity (mm/hr) and sediment load (kg) were generated from the months of March to October 2019. The collected data were analyzed using percentages and degree. It was discovered that the rate of sediment yield was determined by the amount of rainfall and that the rate sediment yield on different landuse types vary widely due to the nature of man environment interactions. The sediment yield from bareland (26.9kg) was greater than fallow land (12.8kg) and that of vegetated land was (4.2kg). In order to protect the environment from erosion (sediment yield), the adoption of environmental education is recommended to track down the rate of sediment yield in the study area. An acceptable way for checking erosion over the affected land surfaces especially the bareland is to cover them with grasses mostly during the rainy season. Finally, this study suggests that man environment relationship should be minima so as not to jeopardize the ecosystem and this can only be achieved through formulation of bye-laws and policies that will guide the use and misuse of the land.

Keywords: : Erosion, Ikpoba, Landuse, Okha, Sediment

Assessment of Heavy Metals Contamination of Surface Water and Sediment of a Tropical Manmade Lake Southwestern Nigeria (Published)

Developing countries including Nigeria are faced with increase generation of domestic, industrial, and agricultural wastes that enter into the surrounding water bodies; and pollutants settle on the sediment (the ultimate sink of contaminant in aquatic environment). These large amount of chemical substances (including heavy metals) released into aquatic environments has put it at risk which could inadvertently pose serious public health hazard. This study assessed the heavy metal concentrations of the surface water and sediments of Dandaru Reservoir, in Ibadan, Nigeria. The level of contamination of lake water and sediment were use to determine the degree of pollution and its potential effects on the environment and public health. Physical and chemical parameters and heavy metals were determined in the lake water using standard methods from April, 2015 to March, 2016 at five different sites of human activities. The physico-chemical parameters determined were within the limits specified by NESREA and WHO.  All metals that were assessed were present in water and sediments (except nickel which was not determined in sediment). Metal concentration in the water followed the following trend Mn,>Fe>Pb>Ni>Zn>Cu>Co>Cd>Cr. Also, metal accumulation in sediments was Fe>Zn>Mn>Pb>Cu>Co>Cd>Cr. The average Igeo class for the sediments in all the stations was 0-2 indicating uncontaminated to moderately contaminated levels.  The concentrations of Pb, Cd, Ni and Mn in water exceeded the NESREA AND WHO standards for domestic water use and aquatic life. These could have adverse effects on the environment and health of people that utilize the water and fish of the Dandaru Reservoir.  Effective monitoring of the livelihood activities and discharges into the reservoir are recommended to prevent further deterioration of the reservoir.

Keywords: Contamination factor, Dandaru Reservoir, Geo-accumulation Index, Heavy Metals, Sediment

Using EF, PLI and Igeo for the Assessment of Heavy Metal Pollution and Sediment Quality of Asejire Reservoir, Southwest Nigeria (Published)

Asejire Reservoir is the largest lake in Southwest Nigeria, supplying domestic and industrial water to more than two million inhabitants of Ibadan and adjoining villages and towns in Oyo and Osun States. A study on the characteristic of sediment quality was conducted to evaluate the heavy metal content of the reservoir. Twenty stations were selected, sampled and analyzed using standard methods.Standard pollution indices such as Igeo, Enrichment Factor, Contamination Factor and Pollution Load Index were deployed to assess the level of heavy metals contamination in the reservoir. The result showed that the sediment was slightly acidic across the study stations, with low conductivity and organic matter content. The heavy metals order of dominance was: Fe>Pb>Cu>Zn>Mn>Ba>Ni>Cr. The mean concentration levels of all the heavy metals were lower than mean background value except Fe and Pb. Analysed data shows that the sediments in the area are rich in Fe with Igeo values > 6, high enrichment and contamination factor. Igeo and CF levels of Pb indicate moderate to no pollution, while other heavy metals indicated low calculated Igeo, EF and CF respectively. The calculated PLI values for all the heavy metals in all the location were < 1, indicating low anthropogenic contamination by these elements and suggesting that the heavy metals were derived mainly from natural sources such as bedrock materials and weathering processes.

Keywords: Asejire, Geo-accumulation Index, Heavy Metals, Pollution Load Index, Sediment