Physicochemical properties, microbial content, heavy metals concentrations and water quality assessment of rainwater from Selected Urban Areas in Abakaliki, Ebonyi State, Nigeria

Abstract

Anthropogenic activities can significantly compromise the quality of rainwater, a commonly presumed pristine water source. This study assessed the physicochemical, heavy metals concentrations, microbial content, water quality and pollution indices of rainwater harvested from commercial and industrial areas during the onset and peak of rainy season. Standard methods of physicochemical analysis and Atomic Absorption Spectroscopy (Model 2610) were employed for analysis, while Water Quality Index was determined by the Weighted Arithmetic Water Quality Index method. Results revealed variations in pH, conductivity, total dissolved solid, between sampling periods. Cadmium levels exceeded the WHO limit of 0.003 mg/L, while microbial analysis detected total bacterial count (TBC), total coliform count (TCC), and E. coli in all samples. Water quality index (WQI) values (ranged from 39.11 to 83.19), indicated poor to good water quality, while pollution index (PI) values (ranged from 0.93 to 3.21) indicated low to very high pollution levels. The results generally indicated better water quality at the peak than at the onset of rainy season due to dilution of the pollutants by frequent rainfall. The study highlights the need for proper treatment of harvested rainwater from industrial and commercial areas to ensure its quality and safety before use.