Comparative Evaluation of Emerging Contaminants in Wastewater from Makurdi and Gwer West Local Government Areas, Benue State, Nigeria

Abstract

Emerging contaminants in wastewater have become major environmental and public health concerns due to their persistence, toxicity, and ecological effects in aquatic environments. This study comparatively evaluated the occurrence and distribution of emerging contaminants in wastewater from Makurdi and Gwer West Local Government Areas of Benue State, Nigeria. A comparative cross-sectional environmental study was conducted using 40 wastewater samples collected from selected drainage systems and wastewater discharge points. Physicochemical parameters, heavy metals, microbial contaminants, and selected emerging contaminants were analysed using standard analytical procedures. Results revealed that wastewater samples from Makurdi recorded higher physicochemical pollution levels compared to Gwer West. Electrical conductivity was 812.4 ± 24.6 µS/cm in Makurdi and 524.7 ± 18.3 µS/cm in Gwer West, while biochemical oxygen demand values were 38.6 ± 3.4 mg/L and 24.1 ± 2.6 mg/L respectively. Caffeine recorded the highest concentration among emerging contaminants with values of 18.42 ± 2.11 µg/L in Makurdi and 9.26 ± 1.34 µg/L in Gwer West. Lead concentrations exceeded WHO permissible limits in both locations, with values of 0.18 ± 0.03 mg/L in Makurdi and 0.07 ± 0.01 mg/L in Gwer West. Microbial analysis showed high total coliform counts of 5.8 × 10⁴ CFU/mL in Makurdi and 2.9 × 10⁴ CFU/mL in Gwer West, alongside the presence of Escherichia coli and Salmonella species. Statistical analysis revealed significant differences in contaminant burden between both locations (p < 0.05). The study demonstrated substantial wastewater contamination, particularly within urban environments, highlighting the need for improved wastewater treatment, environmental monitoring, and pollution control measures.