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Background and objectives: Water pollution from sewage has become a subject of considerable public and scientific concern, given its demonstrated extreme toxicity to human health and biological ecosystems. Hospital wastewater poses a serious health risk to staff, the public, and the environment. This study was conducted to determine the physical, chemical and biological parameters of hospital wastewater from Mohammed VI University Hospital in Marrakech, which is discharged into the municipal sewage system, where it mixes with sewage from urban areas without prior treatment. Methods: This study was conducted between October 2022 and January 2023 with a sampling frequency of 15 days each. Hospital wastewater samples were collected at the main collector of all manholes in the hospital. Findings: Physicochemical characterization of the effluents from each department showed that they are heavily polluted with organic matter, with average values in the range of 750 mg/L COD, 512.14 mg/L BOD5 and 879.86 mg /L TSS. These values are higher than those recommended in the Moroccan discharge standards. Total phosphorus, sulfates, nitrates and nitrites are 5.92 mg/L, 427.97 mg/L, 7.39 mg/L and 0.60 mg/L, respectively. Bacteriological characterization shows that fecal coliform bacteria reach 12 x 106 CFU/100 mL. These effluents also contain pathogens responsible for nosocomial infections, especially Staphylococcus aureus. The ratio COD / BOD5 is about 1.46, a value indicating that hospital wastewater is readily biodegradable. Conclusion: Therefore, proper treatment of these hospital effluents is essential due to their physicochemical and pathogenic bacterial load, which can negatively affect public health and carry the risk of spreading epidemic diseases.

This paper presents the performance and behavior of a multi-soil-layering (MSL) system to remove fecal contamination bacteria indicators and pathogens from domestic wastewater. The experimental setup was performed using a laboratory-scale MSL system (depth 30 × width 36 × height 65 cm). The MSL system was composed of soil mixture blocks (SMB) arranged in a brick-like pattern and surrounded by permeable gravel layers (PL). The SMB comprised sandy soil, charcoal, sawdust and metal iron at a dry weight ratio of 7:1:1:1. The hydraulic loading rate was 200 L m−2day−1. Bacteriological analyses comprised total bacterial count at 22 and 37°C, fecal coliforms, total coliforms,Escherichia coli, streptococci, intestinal enterococci and pathogenic bacteria:Clostridiumsp.,Staphylococcussp.,Pseudomonassp. andSalmonellasp. The best removal efficiency was achieved forStaphylococcussp. by 1.42 log unit, while the lowest removal efficiency was found forE. coliby 1.01 log unit. The mean removal efficiencies of total suspended solids (SS), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorous (TP) were 93, 86, 81, 78 and 80%, respectively. Based on these results, the MSL system could efficiently remove organic matter, phosphorus and nitrogen. However, the performance to reduce bacterial indicators and pathogens was still moderate. [ABSTRACT FROM PUBLISHER]