Modeling the fate and transport of E. coli pathogens in the Tano River Basin of Ghana under climate change and socioeconomic scenarios

• Published in: Environmental science and pollution research international 2024-10, Vol.31 (50), p.60465-60484
• Main Authors: Yeboah, Saeed Ibn Idris Kofi, Antwi-Agyei, Prince, Kabo-Bah, Amos Tiereyangn, Ackerson, Nana Osei Bonsu
• Format: Article
• Language: English
• Subjects: Agricultural runoff; Animal manures; Animal wastes; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biological activity; Climate Change; Climate models; Climate prediction; Dilution; E coli; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Escherichia coli; Feces - microbiology; Ghana; Human motion; Humans; Intergovernmental Panel on Climate Change; Livestock; Manures; Microorganisms; Nonpoint source pollution; Point source pollution; Pollution sources; Population growth; Rainy season; Research Article; River basin development; River basins; Rivers; Rivers - microbiology; Socioeconomic Factors; Socioeconomics; Surface water; Tertiary treatment; Urbanization; Waste Water Technology; Wastewater management; Wastewater treatment; Water Management; Water Microbiology; Water pollution; Water Pollution Control; Water quality
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-024-35123-7

Surface water contamination by fecal matter threatens human health due to human and biological processes within a watershed, making socioeconomic development crucial for predicting and improving microbiological water quality. Consequently, climate change alters climatic parameters that affect flow regimes and the movement and fate of microorganisms. This study assessed the fate and transport of microbial Escherichia coli ( E. coli ) concentrations and their sources in the Tano River Basin in Ghana. Additionally, the study predicted future E. coli concentrations using climate change scenarios from the Intergovernmental Panel on Climate Change (IPCC)’s most recent representative concentration pathways (RCPs) and shared socioeconomic pathways (SSPs). Scenario_1 featured planned urbanization, enhanced manure and wastewater treatment, moderate population, livestock density growth, and climate change. Scenario_2 involved higher population growth, minimal improvements in wastewater management, zero manure treatment, higher livestock population, urbanization, and substantial climate change. Calibration and validation using E. coli data from June 2022 to April 2023 showed good agreement with observed concentrations ( R 2 , 0.75 and 0.89; NSE, 0.69 and 0.68; PBIAS, 3.4 and 1.9, respectively). The measured and modeled E. coli concentrations were high, with the highest recording at 2.39 log cfu/100 ml during the rainy season. The study finds that the main causes of E. coli concentrations (44%) are point sources, primarily from human feces and livestock manure, followed by upstream pollution (34%) and non-point sources (22%). Non-point sources became the predominant contributors during periods of maximum discharge due to runoff from land and the dilution of point sources. Again Scenario_1 E. coli dropped to 68% and 97% of reference point levels by the 2050s and 2100s, respectively. E. coli concentrations decrease even more with subsequent treatment, such as tertiary treatment, manure treatment, or both. The scenario analysis demonstrates the potential for E. coli reduction through wastewater and manure treatment, driven by socioeconomic and climate change scenarios.