Evaluation of the Physicochemical Properties of Waste Dumps in Zaria, Nigeria

Abstract

This study investigates the physicochemical properties and heavy metal concentrations in municipal solid waste (MSW) from the Dogarawa dumpsite in Zaria, Kaduna State, Nigeria. With the growing concerns over the environmental and public health impacts of open dumping practices, particularly in urban areas, a detailed analysis was conducted on waste samples collected from various distances and depths. Parameters such as pH, moisture content, organic matter, and elemental composition were evaluated using standard laboratory procedures, including X-ray fluorescence (XRF), X-ray diffraction (XRD), and atomic absorption spectrometry (AAS).

The results revealed an alkaline pH (7.6), low moisture (2.5%), and moderate organic content (20%). However, the concentrations of heavy metals, particularly zinc (166,970 mg/kg), copper (3,570 mg/kg), and lead (656 mg/kg), were significantly higher than permissible limits set by the World Health Organization (WHO) and Nigeria’s National Environmental Standards and Regulations Enforcement Agency (NESREA). While iron (34,940 mg/kg) remained within safe limits, cadmium was not detected. Mineralogical analysis identified quartz, graphite, anhydrite, muscovite, garnet, and sphalerite, suggesting the presence of both natural and anthropogenic sources.These findings raise serious concerns about the environmental sustainability of the Dogarawa dumpsite. High metal concentrations pose risks to soil quality, groundwater, crop safety, and ultimately human health through the food chain. The study emphasizes the urgent need for improved waste management practices and regular monitoring to prevent further ecological degradation and protect public health in Zaria and similar urban environments.