ABSTRACT
Water is a pre-requisite for life and water of good quality is of basic importance to human physiology and man’s continued existence depends very much on its availability. The natural quality of rivers and streams at any point reflects the quality of upstream contributions of surface runoff and groundwater discharge. This study was carried out to assess the physical and chemical parameters including heavy metal contents of the surface water and sediments of a stretch of Ezenukodo stream, Aghawele community, Edo State, Nigeria.
Samples were collected monthly from May, 2017 to February, 2018 at four study stations. All physical and chemical parameters including heavy metals in water and sediments were analyzed using standard analytical procedures.
The results of surface water analysis showed that physical and chemical parameters and heavy metals investigated ranged from 0.00 to 177.60 and were significant (p <0.05), except for water temperature, pH, dissolved oxygen and chloride. Chromium, manganese and total hydrocarbon content were highly significant (p < 0.01) across the sampling stations. For sediments, physical and chemical parameters and heavy metals values varied from 0.02 to 124.10 and were highly significant (p <0.01), while magnesium, nickel and vanadium were significant (p <0.05) except for pH, EA and total nitrogen which were not significant (p > 0.05) across the sampling stations. Wet season values were higher than those for dry season, but showed no significant difference (p >0.05). Water Quality Index values revealed that water was degraded and unfit for domestic use. Principal component analysis (PCA) highlighted that all physical and chemical parameters and heavy metals in water and sediment were major contributors to water quality, with seasonality playing an augmenting role. Geoaccumulation Index (Igeo), pollution load index (PLI) and potential ecological risk index (PERI) showed that sediments were slightly to strongly polluted. The various heavy metals characterized in the study indicated levels of contamination across the stations. Further studies in Ezenukodo stream is advised to properly ascertain its pollution status and forestall the health implications of water quality degradation. Effective government policies and environmental laws that would ensure proper treatment of wastedisposal, while continuous monitoring programs should be done.
