POLLUTION STATUS OF A SECTION OF THE CALABAR RIVER FROM ADIABO TO NSIDUNG BEACH
E. A. AMAH *
Department of Geology, University of Calabar, Calabar, Nigeria.
EFOSA UDINMWEN
Department of Geology, University of Calabar, Calabar, Nigeria.
I. E. ETI-MFON
Department of Geology, University of Calabar, Calabar, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The pollution status of the Calabar River from Adiabo to Nsidung beach was examined by a field survey of twenty sites during the wet and dry seasons of 2011. The physico-chemical parameters of the water samples analyzed included Temperature(T), Hydrogen ions concentration (pH), Salinity(S), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), turbidity(Tu), iron (Fe), copper (Cu), lead (Pb), zinc (Zn), nickel (Ni), chromium (Cr) and cadmium (Cd). Temperature fluctuated between 25 and 30°C, pH ranged from 4.8 to 6.1, salinity from 0.001 to 0.35 ppt and turbidity 3 to 20 NTU. TDS, TSS, BOD and DO fell in the ranges of 1.14 to 2.40, 10 to 39.2, 2.00 to 2.70 and 4.76 to 6.92 mg/1 respectively for both seasons. The concentration of Fe was found to be the highest of the trace metals while that of Ni was the least. Apart from local variations observed at some sampling points for Pb, Cu and Cd, all other heavy metals were below their WHO safe limits in drinking water. These observed local variations are due to anthropogenic influence and discharge of industrial effluents into the Calabar River. The low levels of BOD and some heavy metals below the WHO limits as observed at most sampling stations indicate that these contaminants have not accumulated to deleterious levels. Hence, the river is only moderately polluted with respect to turbidity and some heavy metals (Fe, Pb, Cu and Cd). Seasonal variation has no effect on the concentration of contaninants in the Calabar River.
Keywords: Pollution status, heavy metals, seasonal variation, Calabar River