Occurrence and Fate of Antibiotics as Trace Contaminants in Wastewater Collection and Disposal Systems - Case Study: University of Dar es Salaam Wastewater Stabilization Ponds, in Tanzania

Abstract

Antibacterial agents (Antibiotics) are emerging micro-contaminants in institutional and municipal wastewater and the aquatic environment. These substances enter wastewater effluents via urine and faeces and by improper disposal of domestic and or medical waste. An environmental analytical study was conducted at the University of Dar es Salaam (UDSM) Waste Stabilization Ponds (WSP). These ponds  receives and treats influents from students’ halls of residence and staff quarters (domestic effluents) as well as hospital effluent sources. The study focused on seven (7) antibiotics commonly used in human therapy, which include Ciprofloxacin, Flucloxacillin, Erythromycin, Ampicillin, Penicillin-V, Amoxycillin and Cloxacillin. In hospital wastewater, the detected antibiotics ranged from 0.98 - 7.10 µg/l, while in student’s halls of residence, the range was 0.2- 1.47μg/l. In WSP influent and effluent concentrations ranged from 8.89 to 63.75µg/l and 1.51 to 28.01µg/l, respectively. The concentration in the sewage sludge was from 72.12 to 370µg/l. Results of this study indicated that significant amount of antibiotics remain in the treatment plants during wastewater treatment process, through sorption to sewage sludge. This suggests that wastewater treatment options currently applicable in Tanzania including different sanitation options should now be designed taking into account the presence of trace concentrations of antibiotics for the purpose of sanitation and environmental protection at large.

Keywords: Antibacterial Agents and Wastewater Stabilization Ponds