Assessment of Physicochemical Properties, Heavy Metal Contamination and Microbial Quality of Sediments from River Benue, Nigeria

Nguseer Ngumaren U, Princewill O and Bethel Uchenna U

Published on: 2026-06-13

Abstract

River sediments serve as critical sinks for pollutants in aquatic ecosystems, reflecting cumulative anthropogenic impacts. This study assessed the physicochemical properties, heavy metal contamination, and microbial quality of sediments from four sites along River Benue, Nigeria (Wadata, Angbaye, North Bank, and Wukurum), during the dry season (January–March 2025). Triplicate sediment samples were collected and analyzed using standard methods for parameters including nitrate, nitrite, fluoride, sodium, magnesium, heavy metals (Cu, Cd, Pb, Zn, Mn) via Atomic Absorption Spectrophotometry, and microbial loads (total viable bacterial count, yeast, mould, and coliform counts). Results showed significant spatial variations (P ≤ 0.05) across sites. Elevated nitrate (up to 5.02 mg/kg) and nitrite (up to 13.01 mg/kg) concentrations were recorded, alongside notably high lead levels at Wukurum (119.01 µg/kg). Other heavy metals were detected at varying concentrations, indicating localized contamination from urban runoff, agricultural activities, and waste disposal. Microbial analysis showed considerable loads, with total coliform counts ranging from 11.02 to 17.01 CFU/g, suggesting fecal contamination. Pearson correlation analysis demonstrated strong positive relationships between sediment parameters and those in fish gills and overlying water, highlighting potential bioaccumulation and pollutant transfer. The findings indicate that anthropogenic pressures are degrading sediment quality in River Benue, posing risks to aquatic life and public health. Regular monitoring, improved waste management, and enforcement of environmental regulations are recommended to safeguard this vital freshwater resource.