Monitoring of the physical parameters and evaluation of the chemical composition of river and groundwater in Calabar (Southeastern Nigeria)
Environmental Monitoring and Assessment
Department of Earth and Ocean Sciences, University of Liverpool, 4 Brownlow Street, Liverpool L69 3GP, United Kingdom; Department of Geology, University of Calabar, Unical Post Office, Calabar 540001, Nigeria
A 12-month study was carried to assess the seasonal and tidal effects on the physical parameters of river and groundwater, which constitute the major potable water sources in Calabar (Nigeria). The study also included an evaluation of the chemical composition of the different water bodies and their relationship. The results show that there was a significant seasonal effect on dissolved oxygen (DO) and nitrate in groundwater on one hand, and on temperature, redox potential (Eh), and DO in river water on the other. Also, a significant tidal influence exists on DO in both river-and groundwater. Comparison between groundwater and river water show statistically significant difference in EC, TDS, Eh, DO, Na, Cl and NO3. The significant differences in EC, TDS, Na and Cl are due to tidal flushing. The difference in Eh is due to geology of the area while, NO3 is as a result of anthropogenic pollution. The concentrations of ions in the river and groundwater for the different seasons and tidal cycles show an inverse relationship, while the river water is generally more concentrated than the groundwater. Using a binary mixing model, estimates show that the degree of mixing of river water and groundwater is low, with values of between 1.93% and 2.76% respectively, in the western and eastern parts of the study area. The study concludes that tidal flushing, anthropogenic effects and oxygen supply during recharge contribute to the shaping of water chemistry in the area. © Springer Science+Business Media B.V. 2008.
Calabar; Chemical composition; Coastal aquifer; Drinking water quality; Season; Aquifers; Biochemical oxygen demand; Dissolution; Dissolved oxygen; Dissolved oxygen sensors; Electric conductivity measurement; Groundwater resources; Hydrogeology; Oxygen supply; Physical properties; Rivers; Water distribution systems; Water pollution; Water quality; Potable water; dissolved oxygen; drinking water; ground water; nitrate; river water; chemical composition; coastal aquifer; dissolved oxygen; groundwater; nitrate; redox potential; river water; water chemistry; article; chemical composition; geology; monitoring; Nigeria; oxidation reduction potential; oxygen supply; physical chemistry; seasonal variation; statistical significance; temperature; water analysis; water pollution; Chlorine; Cities; Electric Conductivity; Environmental Monitoring; Geologic Sediments; Hydrogen-Ion Concentration; Nigeria; Nitrates; Oxidation-Reduction; Oxygen; Rivers; Seasons; Sodium; Temperature; Water Pollutants; Africa; Calabar; Cross River [(STT) Nigeria]; Nigeria; Sub-Saharan Africa; West Africa