Antibiotic Residues in Effluent from the Cocody-Angré University Hospital Center (UHC), Côte d’Ivoire
Gnagne Agness Essoh Jean Eudes Yves *
Laboratory of Thermodynamics and Environmental Physicochemistry, Training and Research Unit in Fundamental and Applied Sciences (UFR-SFA), Nangui Abrogoua University, 02 BP 801 Abidjan, Abidjan, Côte d’Ivoire.
Seka Yapoga Jean
Institute of Agropastoral Management (IGA), Peleforo GON COULIBALY University of Korhogo, Côte d’Ivoire.
Ahoule Dompé Ghislain Maxime
Geoscience and Environment Laboratory, Training and Research Unit in Environmental Sciences and Management (UFR-SGE), Nangui Abrogoua University, 02 BP 801 Abidjan, Abidjan, Côte d’Ivoire.
Chonou Assi Hubert
National Institute for the Training of Health Workers, Abidjan, Côte d’Ivoire.
N’gatta N’goran Samson
National Institute for the Training of Health Workers, Abidjan, Côte d’Ivoire.
Ballet Tiama Guy Nicaise
Laboratory of Environmental Sciences, Training and Research Unit in Environmental Sciences and Management (UFR-SGE), Nangui Abrogoua University, 02 BP 801 Abidjan, Abidjan, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
This study assessed the occurrence and removal of amoxicillin (AMX), ceftriaxone (CTR) and gentamicin (GM) in effluents from the Cocody-Angré University Hospital Center, Côte d’Ivoire. Four sampling campaigns were conducted between 24 November and 28 December 2023 at the inlet and outlet of the hospital wastewater treatment plant. Daily composite samples were analysed for physicochemical parameters and antibiotic residues using HPLC-UV methods. The raw effluent showed a high organic and suspended-solids load, with chemical oxygen demand (COD) of 449.5 mg O₂/L, biochemical oxygen demand (BOD₅) of 112.26 mg O₂/L and suspended solids (SS) of 227 mg/L. The COD/BOD₅ ratio was 4.00, indicating low biodegradability. Median inlet concentrations were 0.63 µg/L for AMX, 0.55 µg/L for CTR and 1.06 µg/L for GM. Treatment reduced COD by 68%, BOD₅ by 59% and SS by 73.56%. Antibiotic removal differed markedly among the three compounds: CTR decreased by 83.63%, GM by 19.81%, whereas AMX showed a negative removal rate of −65.07%, with a higher outlet concentration than inlet concentration. These findings indicate that the existing biological treatment reduced conventional pollution indicators but did not achieve consistent removal of all investigated antibiotic residues. The results support careful evaluation of additional treatment options for limiting pharmaceutical micropollutant discharge from hospital wastewater.
Keywords: Antibiotic removal, biological wastewater treatment, Cocody-Angré, university hospital, hospital wastewater, purification performance