Water Quality Assessment of Slaughterhouse Wastewater Draining into the Oued Beht River, Morocco

Slaughterhouses are known for high water consumption due to the variety of processes requiring water. The wastewater produced by these facilities significantly impacts the environment. This study aimed to assess the level of pollution caused by slaughterhouse waste discharged into the Beht River in Sidi Slimane, Morocco. From October 2012 to July 2013, ten urban wastewater collectors (C1 to C10) were selected based on their location—either within the slaughterhouse area or carrying wastewater from it. Water samples were collected from these collectors and subjected to chemical and bacteriological analyses. The parameters measured included total suspended solids (TSS), biological oxygen demand over five days (BOD₅), chemical oxygen demand (COD), fecal coliforms (FC), and fecal streptococci (FS). In addition, a multivariate analysis was conducted, including principal component analysis (PCA) of the studied parameters. The results indicated an increase in contamination levels, particularly FC and FS, from upstream to downstream. The PCA revealed two principal components explaining 60.8% of the variance and demonstrated a strong correlation between physical, chemical, and temporal factors. The analyses showed increasing pollution levels and decreasing oxygen concentrations over time. When analyzed by station, the data explained 56.86% of the variance, confirming a strong correlation between physical, chemical, and spatial factors. Higher levels of pollution were observed at collectors C1 to C10 compared to the effluents from slaughterhouse outlets P1 and P2. The high microbial load in the water samples indicates significant fecal contamination, pointing to substantial pollution from slaughterhouse waste.