Geospatial Variability and Distribution of Total Petroleum Hydrocarbons (TPH) in Soot-Contaminated Rain and Rivers at Oyigbo, Niger Delta, Nigeria

Abstract

This comprehensive study delves into the analysis of Total Petroleum Hydrocarbon (TPH) concentrations in soot-contaminated rain and rivers within Oyigbo, Rivers State, Niger Delta, Nigeria, with a primary focus on unraveling the geospatial variability and distribution of TPH in the impacted water sources. The study adopts a multifaceted methodology, incorporating fieldwork, sampling, laboratory analysis, and geospatial mapping using ArcGIS 10.4 software to elucidate spatial variations. Results spotlight the highest rainwater TPH concentrations at MKT 7 - Umuosi Market (128.179 mg/L) and the lowest at SET 13 - Okpontu Settlements (8.976 mg/L), situated in the Okoloma and Umu Agbai-Obete axis, respectively. Likewise, river water exhibits the highest TPH at RVR 5 - Imo River (37.118 mg/L), and the lowest at RVR 6 - Imo River (187.118 mg/L), at Okoloma and Umu Agbai-Obete axis. Analysis of the 41 samples indicates that 19 locations surpass the 50 mg/L acceptable limits set by the World Health Organization (WHO, 2017), and the Department of Petroleum Resources (DRP - EGASPIN, 2018), Nigeria standards, with 10 locations recording concentrations above, and 12 locations falling below 30 mg/L. These findings underscore approximately 46% exhibiting high, 24% displaying medium, and 29 % showcasing low concentrations across the study area, following a spatial pattern with higher pollution dispersion in the Northern and North-western regions at Okoloma and Obigbo axes, and lower pollution levels in the Eastern regions at Umu Agbai-Obete axis. In essence, this study provides a comprehensive insight into TPH in soot-contaminated water resources in Oyigbo, contributing significantly to the advancement of knowledge regarding spatial variation, distribution, and implications for water quality management. Furthermore, it serves as a valuable resource for policy development, offering evidence for targeted environmental programs and practical assistance to environmentalists, researchers, government agencies, and the public in the assessment and enhancement of water quality in affected communities.