ABSTRACT
Determination of the physical and chemical parameters of Awoye water bodies and heavy metal concentration of water, sediment and crab (Callinectes pallidus) were conducted between January – June, 2015 to assess its pollution status. Physio-chemical parameters such as pH, water temperature, conductivity, TDS, TSS, Alkalinity, Colour, Chloride, Turbidity, Sulphate, Nitrate, Phosphate, Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Dissolved Oxygen (DO), Oil and Grease, and heavy metals (Fe, Zn, Mn, Cu, Ni, Cd, V, Cr, Pb) in water sediment and crab were carried out monthly for six months across dry and rainy season. Three (3) stations, (Awoye gulf, Stone jetty and NNPC platform) were selected based on differences in effluent characteristics. Collection, treatment and determination of the physical and chemical parameters were carried out using methods limnological standards. Digestion of water was with concentrated nitric acid. Sediment and crab digestion were carried out using nitric-perchloric-sulphuric acid wet digestion method, while the extraction techniques of Atomic Absorption Spectrophotometer (ASS). The results of physio-chemical parameters of water varies by stations and months and seasons. The mean values of physio-chemical parameters in water are: pH (5.63±0.18), Air temperature (27.78±0.64), water temperature (23.23+0.37°c), conductivity (1150.56+26.02µS) TDS (75.28+13.01mg/l) TSS (19.86+10.79mg/l), alkalinity (36.02+1.11mg/l), colour (6.02+1.35), Turbidity (17.56+0.24NTU), chloride (151.17+7.81mg/l), salinity (595.17+14.520 /00), sulphate (11.78+0.72mg/l), phosphate (6.03+0.67mg/l), COD(78.08+4.74mg/l), DO(9.21+1.61mg/l), BOD (4.88+2.59mg/l), O/G (5.82+5.32mg/l) Na+ (13.77+1.14mg/l), K+ (22.76+1.03mg/l), Mg2+ (4.21+0.22mg/l), Ca2+(1.55+0.64mg/l). Heavy metals were more in the crab and least in water and sediment respectively. All heavy metals had bioaccumulation value greater in crabs than in water. Results of heavy metals and physicochemical parameters were higher when compared to limits by W.H.O, FEPA and DPR for portable drinking water, and WHO/FAO for fish and fishery products. Therefore, the water and the crab from this water body are not fit for human consumption.
