Assessment of some physicochemical parameters and heavy metals in River Benue at Wurukum abattoir, Makurdi Metropolis, Benue State, Nigeria

Abstract

This study assessed the impact of abattoir effluents on the water quality of River Benue around the Wurukum Abattoir, Makurdi, Benue State, Nigeria, using selected physicochemical parameters and heavy metal concentrations as pollution indicators. Water samples were collected from four sampling stations and analysed using standard methods recommended by the American Public Health Association (APHA) and the Association of Official Analytical Chemists (AOAC). Temperature, pH, electrical conductivity (EC), dissolved oxygen (DO), biochemical oxygen demand (BOD), total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), total hardness (TH), and total acidity (TA) were measured, while heavy metals were analysed by atomic absorption spectrophotometry (AAS). Temperature (28.97--29.30 ⁰C), pH (6.3--6.8), and EC (30--90 μS/cm) were within acceptable ranges for freshwater systems. Total hardness ranged from 158 to 180~mg/L, indicating hard-water conditions. DO concentrations were low (0.94--2.16~mg/L), indicating limited oxygen availability. BOD ranged from 2.2 to 79~mg/L, with the highest value at the abattoir discharge point, suggesting substantial organic loading from untreated effluent. Chromium (0.327--0.532~mg/L), lead (1.885--2.716~mg/L), and manganese (0.075--1.772~mg/L) exceeded permissible drinking-water limits, while cadmium was not detected. The findings indicate that abattoir effluents and other anthropogenic activities contribute to water-quality deterioration in River Benue.