Physicochemical and Heavy Metal Characterization of River Kapingazi in Embu County, Kenya

Abstract

Surface water provides crucial support to the aquatic ecosystem and humans in numerous ways. However, its quality is paramount in determining its impact on the health of the aquatic ecosystem and humans. Currently, the malady of pollution arising from anthropogenic activities poses a significant threat to the quality of most rivers. The quality of water in the Kapingazi river in Embu County has received limited attention which is a concern that needs to be addressed. This study therefore, sought to investigate the status of water quality in river Kapingazi. The study analyzed 96 samples from four locations in a span of eight months which combined the dry and wet seasons of the year. Parameters measured in-situ included turbidity, pH, total dissolved solids (TDS), temperature, dissolved oxygen (DO) and electrical conductivity (EC) while ex-situ parameters were phosphates, nitrates and concentrations of heavy metals: iron and manganese. Results showed that Water Quality Index (WQI) during the drought period was74.05, suggesting that the water quality is only recommended for agricultural and industrial applications. During wet season, the water quality index was 89.67, reflecting a poor status, as more contaminants were likely introduced through surface runoff. Overall, the WQI averaged to 88.02. This study concludes that water in River Kapingazi is not suitable for human consumption; therefore, appropriate treatment is essential prior to its use. Similarly, the findings indicate that both rainy and drought periods significantly affect water quality, presenting challenges for its use for various purposes. It is recommended that the allocation of resources towards water treatment facilities and regulation of pollution sources should be enforced to ensure the safety of river water for diverse applications