Keywords
N’djili River
biodegradability
wastewater management
seasonal variability
slaughterhouse
How to Cite
Abstract
Introduction
Slaughterhouse effluent is a major source of organic pollution that can impair surface water quality, particularly in developing countries where wastewater treatment infrastructure remains inadequate.
Purpose
This study assessed the physicochemical quality of wastewater from the Masina public abattoir in Kinshasa to evaluate pollution levels and associated environmental risks.
Methods
A longitudinal observational study was conducted during the wet and dry seasons of 2025. Sixteen sampling campaigns were executed, comprising ten in situ measurement events and six laboratory analysis events. Samples were collected from four distinct points: the slaughter area, the collection point (collector), the discharge point, and an upstream reference site on the N’djili River. Analyzed parameters included temperature, pH, electrical conductivity, turbidity, total suspended solids (TSS), biological oxygen demand (BOD5), chemical oxygen demand (COD), and nitrates (NO₃⁻). Data were subjected to analysis of variance (ANOVA) followed by Fisher’s Least Significant Difference (LSD) test (α = .05).
Results
Significant seasonal variations were observed (p < .05), with pollutant concentrations consistently higher during the dry season. The highest organic loads occurred at the collector, where COD reached 190.27 ± 1.07 mg/L and BOD5 reached 121.13 ± 3.83 mg/L, significantly exceeding international guideline limits. High nitrate concentrations were recorded at the collector, reaching 450.46 ± 2.53 mg/L. The BOD5/COD ratios ranged from 0.54 to 0.65 across sites, confirming that the effluents are highly biodegradable.
Conclusion
Untreated effluent from the Masina public abattoir is a major contributor to the degradation of water quality in the N’djili River. Implementing biological treatment systems, such as constructed wetlands, is essential to mitigate environmental degradation and safeguard public health.
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Copyright (c) 2026 Kasogo, B. P., Lusasi, S. W., Mesongolo, L. C., Mulaji, K. C., Musibono, E. D., Biey, M. E.