Effect of abattoir effluents on the physicochemical properties of a receiving watershed in an urban community

Abstract

Abattoir effluent quality assessment is essential in providing sustainable water resource management developments. This study was carried out to assess the impact of abattoir effluent discharges on the physicochemical qualities of a receiving watershed in an urban community. Some physicochemical indicator variables of the effluent discharge and the receiving watershed were determined using standard analytical procedure. Ranges of values obtained from the study were: pH ( 5.79 ± 0.66 - 6.58 ± 0.46), electrical conductivity, EC (23.00 ± 13.89 - 305.33 ± 147.05) μS/cm, temperature, T (29.10 ± 1.01 - 29.80 ± 0.34) C, total dissolved solids, TDS (11.33 ± 6.65 - 153.00 ± 73.72) mg/L, total suspended solids, TSS (7.50 ± 0.78 - 30.93 ± - 5.08) mg/L, alkalinity, ALK (6.10 ± 0.00 - 63.03 ± 43.81) mg/L, chloride, Cl^- (5.91 ± 2.04 - 29.57 ± 7.38) mg/L, calcium, Ca²⁺ (1.92 ± 0.00 - 19.66 ± 7.29) mg/L, magnesium, Mg²⁺ (0.52 ± 0.22 - 5.05 ± 2.42) mg/L, total + hardness, TH (7.47 ± 3.32 - 69.92 ± 27.37) mg/L, Sodium, Na⁺ (1.71 ± 0.18 - 12.86 ± 2.29 ) mg/L, Potassium, K⁺ (0.75 ± 0.35 - 9.33 ± 2.23) mg/L, turbidity (8.66 ± 1.35 - 63.12 ± 12.43) NTU, dissolved oxygen, DO (1.93 ± 0.41 - 5.86 ± 1.00) mg/L, biochemical oxygen demand, BOD (2.80 ± 0.60 - 33.06 ± 14.36) mg/L, chemical oxygen demand, COD (14.00 ± 2.00 - 60.66 ± 12.70) mg/L, sulphate, SO₄^2- (0.84 ± 0.61 - 7.18 ± 0.88) mg/L, phosphate, PO₃^-4 (0.01 ± 0.00 - 2.10 ± 1.22) mg/L, nitrate, NO₃^- (0.37 ± 0.42 - 8.70 ± 1.33) mg/L and ammonium NH₄⁺ (0.02 ± 0.01 - 2.46 ± 0.78) mg/L. The above data were compared with the recommended 4 permissible limits set by the World Health Organization (WHO) and Federal Ministry of Environment (FME). Comparative correlation analysis of the effect of abattoir effluents on the receiving watershed from the studied locations revealed significant positive and negative correlations at probability value (p-value) of 0.05 or 0.01. The study revealed that the effluents discharged from the abattoir facilities pose serious health and environmental risk to communities which rely on the receiving watershed as primary source for domestic or recreation activities.

Keywords: Abattoir effluent; Pollution; Aquatic environment; Waste disposal; Water quality