Environmental Pollution loads on surface Water Chemistry and Potentially Ecological Risks of Inland Aquatic Ecosystem In South-eastern State, Nigeria

Abstract

Abstract The study assessed water chemistry of Nworie inland aquatic ecosystem in South eastern, Nigeria. Water samples were taken from the upper, middle, and lower river at 200m interval. Data collected were subjected to multivariate Statistics. Results of physicochemical tracers indicated mean Ph, CaCO3, Ca2+&Chemical Oxygen Demand (COD) to be 6.2, 172.8mg/l, 103.1mg/l, 16.50mg/l respectively above the WHO critical limits, while others were below the limits. Heavy metals (mg/l) showed mean values viz: Cd 2+(0.053), Cr2+(0.049), Fe2+(0.443), Ni2+(0.024), and Pb (0.787) which were all above some critical global limits, except for Cu2+ and Zn2+ and in decreasing abundance: Pb2+≥ Fe2+≥Cu2+≥Zn2+≥Cd2+≥ Cr2+≥ Ni2. Physicochemical tracers and elements in water correlated in both positive and negative directions. Principal component analysis (PCA) showed significant loads of PC3; CaCO3, NO3, COD, DO, Ca, PO4, Cu, Fe, Zn, PC2; moderate loads of SO4, Cl, & Na originating from complex human activities. Contamination factor (Cf), pollution load & ecological risk recorded low in decreasing order: Cr2+≥Zn2+≥Ni2+≥ Cd2+≥ Pb2+ ≥ Cu2+≥ Fe2+ with contamination degree in order of: Lower River (LR)≥Upper River(UR)≥Middle River(MR) and low risk index. Continuous monitoring of human activities along the whole River is important to mitigate any aquatic ecosystem damage for water quality sustainability.