Distribution of Microplastics in Sediment Samples from the Upper Benue River (ibi), Nigeria

Microplastic pollution has emerged as a critical environmental challenge, particularly in aquatic ecosystems where its persistence poses significant ecological and health risks. This study investigated the distribution of microplastics in sediment samples from the Benue River (Ibi), Nigeria, with the aim of identifying microplastic types, determining their concentration, and assessing their distribution across different locations in the river. A systematic sampling approach was employed, where sediment samples were collected from five designated points along the river, including the north and south banks, as well as mid-river locations. Laboratory analysis involved sieving, organic material digestion, density separation, and high-performance liquid chromatography (HPLC) with fluorescence detection to isolate and quantify microplastics. The statistical analysis was conducted using SPSS 16.0 software, with ANOVA applied to assess variations in microplastic concentration among the sampling sites. The results confirmed the widespread presence of microplastics in all sediment samples, with eight distinct types identified: polyamide, polystyrene, polypropylene, polyethylene, ethylene glycol, terephthalic acid, acrylic acid, and polyester. The highest microplastic concentration was recorded in the mid-river sample (4633.61 ppb), followed by the north bank (2576.16 ppb and 2465.64 ppb at different points), while the south bank had the lowest concentration (2401.81 ppb and 1365.97 ppb at different points). The distribution pattern suggests that hydrodynamic factors, pollution sources, and sedimentation dynamics play a crucial role in microplastic accumulation. The findings of this study highlight the urgent need for pollution control measures to mitigate microplastic contamination in the Benue River.