Surface water quality of the Magdalena River in the Colombian Caribbean: future solutions for treatment wastewaters

Area of Science:

• Environmental Science
• Water Resource Management
• Ecotoxicology

Background:

• Anthropogenic activities exert increasing pressure on global freshwater ecosystems.
• Hydrological quality studies are crucial for effective water resource management, especially in complex port environments.
• Integrated water quality assessments in tropical fluvial-port ecosystems are notably scarce.

Purpose of the Study:

• To conduct a comprehensive multitemporal assessment of surface water quality in the Magdalena River near a Colombian port.
• To identify key physical, chemical, and microbiological drivers of water quality degradation.
• To evaluate the effectiveness of multivariate and index-based approaches for water quality monitoring in tropical regions.

Main Methods:

• Analysis of physical, chemical, and microbiological parameters from 2016 to 2023 at two monitoring points.
• Application of multiple pollution indices: Water Quality Index (WQI), Índice de Calidad de la Matéria Orgánica (ICOMI), Índice de Contaminación por Metales Orgánicos (ICOMO), Índice de Contaminación por Sólidos Suspendidos (ICOSUS), Índice de Contaminación por Trofía (ICOTRO), and Índice de pH (ICOpH).
• Statistical analysis including two-way ANOVA, Spearman correlation, and Principal Component Analysis (PCA).

Main Results:

• Significant temporal variations in water quality were observed, with deterioration linked to the rainy season, agricultural activities, and untreated wastewater.
• Principal Component Analysis identified biodegradable organic matter (BOD₅), oxidizable load (COD), oils and greases (FO), and coliforms as primary pollution indicators.
• Water Quality Index (WQI) indicated moderate quality (0.46–0.65), while ICOMO and ICOTRO highlighted persistent eutrophic conditions and suspended solids, particularly upstream.

Conclusions:

• The study provides a vital long-term baseline for understanding water quality dynamics in tropical fluvial-port systems.
• Strengthening wastewater treatment, promoting sustainable agriculture, and expanding environmental monitoring are essential.
• Integrated assessments using multivariate and index-based methods are effective for managing water resources in complex ecosystems like the Magdalena River.