Physicochemical Assessment of Water and Sediments of Santa Barbara Estuary of the Niger Delta, Nigeria

Abstract

The concentration of water and sediment quality parameters such as Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), pH, Sulphate, Potassium, Calcium, Nitrate, Total Hydrocarbon Concentration (THC), Total Organic Carbon (TOC), and Phosphate was studied between April 2021 to March 2022. The mean concentration of the parameters in the various stations range between 6.70 – 7.04; 29.09 – 29.45 oC; 5.11 – 5.77 mg/l; 75.72 – 81.85 mg/l; 89.23 – 90.97 mg/l; 1.29 – 1.88 mg/l; 2.41 – 2.86 mg/l; 1.53 – 2.14 mg/l; 7.08 – 19.58 mg/l, 0.27 – 0.62 mg/l, and 2.34 – 2.52 mg/l for pH, Temperature, Dissolved Oxygen, Potassium, Calcium, Phosphate, Sulphate, Nitrate, Turbidity, Biological Oxygen Demand, and THC respectively. In sediment, the mean concentration of parameters was between 5.12 – 5.62; 1.73 – 2.36 mg/kg; 3.96 – 5.11 mg/kg; 1.67 – 2.15 mg/kg; 298.90 – 409.40 mg/kg; 419.25 – 491.53 mg/kg; 7.14 – 7.53 %, and 98.94 – 130.55 mg/kg for pH, Nitrate, Sulphate, Phosphate, Calcium, Potassium, TOC, and THC. In water, there was a significant variation across study stations (p<0.05), in the concentration of phosphate, nitrate, and turbidity, but no such variation (p>0.05) occurred in the other parameters. In sediments, there were also spatially significant variations (p<0.05) in the concentrations of pH, Nitrate, Sulphate, and Phosphate. Overall, the concentrations of these parameters were higher in sediments than in water. Hierarchical Cluster Analysis grouped the physicochemical parameters of water and sediments from the study area into three clusters. These findings reflect the dynamic nature of the aquatic environment and the influence of various factors on water and sediment quality.