Environmental Assessment of Heavy Metal Contamination and Physicochemical Properties in Abattoir Wastewater

This study assessed the physicochemical properties and heavy metal contamination in abattoir wastewater and tap water from two abattoirs in Lagos State, Nigeria. Wastewater and tap water samples were collected between February and March 2018, with tap water serving as the control. Parameters analyzed included pH, temperature, and concentrations of Ca, Cd, Fe, Mn, Pb, and Zn. Results showed that pH and temperature met regulatory standards, while Pb and Zn in wastewater exceeded FMENV limits for surface water discharge. Similarly, tap water samples contained Cd, Fe, Mn, and Pb above WHO drinking water standards. The metal pollution index indicated higher contamination in Oko-Oba Abattoir wastewater (5.12 mg/L) than in Ejigbo (3.42 mg/L). Statistical analysis revealed a significant difference in Mn levels between tap water from the two abattoirs, while other parameters showed no significant variation. These findings highlight the need for effective pre-treatment and regulatory monitoring to mitigate pollution and health risks associated with abattoir wastewater discharge.