Pollution Status of River Niger Around Ajaokuta Steel Company, Kogi State, Nigeria

Water samples from the River Niger near the Ajaokuta Steel Company were evaluated for physical and chemical characteristics from six selected sites in wet and dry seasons. Physico-chemical parameters such as temperature, pH, total dissolved solids, biological oxygen, electrical conductivity, total alkalinity, total hardness, chemical oxygen demand, magnesium, calcium, sulphate, manganese, chloride, total iron, and nitrate were determined utilising standard techniques. The comprehensive pollution indices, water quality indices, single factor pollution indices, and contamination indices were utilised to assess the degrees of river pollution in the study site. A flame atomic absorption spectrophotometer was used to assay the samples for their heavy metal content. Quality control procedures included blank determination, recovery analysis, and calibration of standards. Descriptive and inferential statistics were employed for data interpretation. The results revealed that all the physicochemical parameters were below the recommended allowable limit for drinking water, except Fe. Most of the physicochemical parameters were higher in the dry season, except hardness, magnesium, Chlorine, and iron. The water quality index was classified as 'good' and 'poor' for the dry season (85.72) and the wet season (108.56), respectively. Comprehensive pollution indices indicated slight and moderate pollution in dry (0.82) and wet (1.09) seasons, respectively, while contamination index classified the water as highly contaminated in both dry (97.67) and wet (203.34) seasons. The overall water quality indices were classified as polluted. Therefore, ensuring the safety of the river source is crucial to safeguard public health and aquatic biodiversity. Keywords: Surface Water, Quality, Contamination, Environmental