Seasonal Variation of Groundwater Quality in Bonny Island, Rivers State Nigeria
Ejike Okoli
Centre for Occupational Health, Safety and Environment (COHSE), University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
Ify L. Nwaogazie *
Department of Civil & Environmental Engineering, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
Ejikeme Ugwoha
Centre for Occupational Health, Safety and Environment (COHSE), University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This study investigated the seasonal variations in physicochemical parameters, heavy metals, and petroleum hydrocarbons in groundwater samples collected in nine locations in Bonny Island, Rivers State Nigeria. The water samples for the dry season were collected in December and January while for the wet season, water samples were collected in July and October. A quantitative approach was employed, involving the collection of quantitative data through field sampling and laboratory analysis. Physicochemical parameters, including pH, electrical conductivity, dissolved oxygen, and nutrient levels, were measured using standard analytical techniques. Heavy metal concentrations (Fe, Cd, etc.) were determined using atomic absorption spectrophotometry, while petroleum hydrocarbons (total hydrocarbons and polycyclic aromatic hydrocarbons) were analyzed through solvent extraction and gas chromatography techniques. The study revealed significant seasonal variations in several parameters, with notable significant decreases in phosphate during the wet season and significant increases in chromium and cadmium levels during the dry season (p-value < 0.05). Petroleum hydrocarbon concentrations also exhibited seasonal fluctuations, potentially influenced by precipitation patterns, oil and gas activities, and accidental spills or leaks which were observed during the dry season.
Keywords: Groundwater contamination, seasonal variations, physicochemical parameters, heavy metals, petroleum hydrocarbons, oil and gas industry, bonny island