Department of Civil and Environmental Engineering, University of Energy and Natural Resources, P.O. Box 214, Sunyani, Ghana.
Regional Centre for Energy and Environmental Sustainability (RCEES), University of Energy and Natural Resources, P. O. Box 214, Sunyani, Ghana.
Environ Sci Pollut Res Int. 2024 Oct;31(50):60465-60484. doi: 10.1007/s11356-024-35123-7. Epub 2024 Oct 9.
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, 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.
地表水受到粪便污染会威胁人类健康，因为流域内存在人类和生物过程，这使得社会经济发展对于预测和改善微生物水质至关重要。因此，气候变化改变了影响水流模式以及微生物迁移和归宿的气候参数。本研究评估了加纳塔诺河流域中微生物大肠杆菌 (E. coli) 浓度的归宿和传输及其来源。此外，该研究还使用政府间气候变化专门委员会 (IPCC) 最近的代表性浓度路径 (RCP) 和共享社会经济路径 (SSP) 下的气候变化情景来预测未来的 E. coli 浓度。情景 1 以计划中的城市化、加强的粪便和废水处理、适度的人口增长、牲畜密度增长和气候变化为特征。情景 2 则涉及人口增长更快、废水管理改善有限、零粪便处理、更高的牲畜数量、城市化和显著的气候变化。2022 年 6 月至 2023 年 4 月的 E. coli 数据的校准和验证表明，与观测浓度具有良好的一致性（R 为 0.75 和 0.89；NSE 为 0.69 和 0.68；PBIAS 为 3.4 和 1.9）。测量和模拟的 E. coli 浓度很高，雨季的最高记录为 2.39 log cfu/100 ml。该研究发现，E. coli 浓度的主要原因（44%）是点源，主要来自人类粪便和牲畜粪便，其次是上游污染（34%）和非点源（22%）。在最大排放期间，由于土地径流和点源稀释，非点源成为主要的贡献源。情景 1 下，到 2050 年代和 2100 年代，E. coli 分别降至参考点水平的 68%和 97%。通过后续处理，如三级处理、粪便处理或两者结合，E. coli 浓度会进一步降低。情景分析表明，通过废水和粪便处理，在社会经济和气候变化情景的驱动下，E. coli 有减少的潜力。
