Quality Assessment of Wastewater: Physicochemical and Bacteriological Evidence from Dutse Abattoir, North-West Nigeria

This study was conducted to determine the physicochemical properties of the wastewater as well as isolate and identify heterotrophic bacterial populations in the wastewater while comparing results obtained with permissible standards of the World Health Organisation (WHO) and the National Environmental Standards and Regulations Enforcement Agency (NESREA). Grab sampling method was used to collect 12 wastewater samples over four weeks. Temperature, pH, turbidity, electrical conductivity (EC), nitrates, sulfate, phosphate, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total heterotrophic bacterial count (THBC) were analyzed using standardized methods. Results obtained show that the overall mean values of pH (6.91), EC (2.6 µS/cm), sulfate (81.7 mg/L), DO (7.05 mg/L), BOD (1310 mg/L) and COD (3543 mg/L) conformed with allowable limits. Nitrate (821.4 mg/L) and phosphate (231.7 mg/L) were found to be above the permissible standards. Mean BOD values were not significantly different (p > 0.05) from each other during sampling. THBC for all the samples exceeded the WHO limit, as it ranged between 1.9×10⁴ and 5.6×10² CFU/mL. Results obtained during the conduct of this study have clearly shown that the wastewater generated from the Dutse abattoir was unfit for discharge into the environment.