GIS Analysis of Organo-Contaminants and Iron Linked to Groundwater and Sediment at Boreholes in Aluu, Delta Region, Nigeria

Abstract

The source of high fever and gastrointestinal disorders in humans after groundwater consumption in this part of the delta region in Nigeria is unknown. Spatial data engineered by GIS interpretation of organo-contaminants bound to groundwater and borehole sediment provides baseline data and information on the impact of iron and organo-contaminants on groundwater quality in Aluu. A total of 10 water and sediment samples were collected at a depth of 45 m from 10 boreholes within Aluu and analyzed in triplicate. The choice of 45 m implies the occurrence of sediments bearing groundwater for a deep well. A particle size analyzer was used to perform particle size analyses of the air-dried sediments. The American Public Health Association Method (APHA) was used to perform the chemical analysis of the water samples. Here, a liquid-liquid extraction procedure was conducted on the samples using 30 mL dichloromethane (DCM) as the extraction agent. The results were subjected to statistical validation, spatial data and GIS analysis. The textural characteristics possessed a mean grain size from fine sand (2.03) to medium sand (4.3), poorly sorted of 1.45 to 2.1, skewness of near-symmetrical (0.02), meso-kurtic kurtosis of 0.5 to very platy-kurtic of 2.09. Total petroleum hydrocarbon was 0.033 mg/L to 0.88 mg/L, and total hydrocarbon content and iron were 1.65 mg/L to 3.41 mg/L, and 2.98 mg/L-0.48 mg/L respectively. The results of these contaminants bound to sediments and water were above the acceptable limits of the World Health Organization. The ingress of contaminants into the groundwater was significantly controlled by the characteristics of the borehole sediment.