Effects of KMnO4 amounts on antibacterial properties of activated carbon for efficient treatment of northern Benin hospital wastewater in a fixed bed column system.

In this study, the wastewater from the Departmental Hospital Center of Atacora in Benin was characterized and then treated with activated carbon/potassium permanganate (AC/KMnO ₄ ) composite in a fixed bed column system. The AC/KMnO ₄ composites with impregnation ratios range 0.025-0.100 were prepared from peanut shell activated carbon and potassium permanganate. The wastewater characteristics revealed that 75% of Escherichia coli strains identified were extended-spectrum lactamases (ESBL) with CTX-M dominance, while 25% of Staphylococcus aureus strains produced Panton and Valentine leucocidin and 77.80% of Salmonella typhi strains were resistant to Trimethoprim/Sulfamethoxazole. The fixed bed column system results showed removal efficiency of 72.18 ± 4.98% turbidity, 63.12 ± 4.11% COD, 0.70 ± 0.04 log ₁₀ against E. coli and 3.82 ± 0.01 log ₁₀ against S. typhi strains using activated carbon as adsorbent with 0.7 cm bed depth after 3 h of treatment. The composite adsorbent AC/KMnO ₄ significantly increased the effectiveness of treatment due to the strong oxidant power of KMnO ₄ in the composite material. The results depicted a removal rate of 83.88 ± 5.00%, 89 ± 1.95%, 90 ± 0.65% turbidity, 66.47 ± 1.62%, 69.82 ± 2.00%, 78.20 ± 2.82% COD, 2.0 ± 0.08 log ₁₀ , 5.0 ± 0.07 log ₁₀ against E. coli and 3.82 ± 0.01 log ₁₀ against S. typhi strains using AC/KMnO ₄ with 0.025, 0.050 and 0.100 ratios respectively at 0.7 cm bed depth. Finally, AC/KMnO ₄ revealed more adsorption potential and antibacterial property than AC, hence, the composite material could be used as a cost-effective adsorbent for efficient removing of multi-resistant bacteria from hospital wastewater.
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