Occurrence of selected pharmaceuticals in water and sedimentof Umgeni River, KwaZulu-Natal, South Africa

Abstract

Selected pharmaceuticals including antibiotics, an-tipyretics, a stimulant, an antiepileptic and an antipsychoticdrug were determined in wastewater, surface water and sedi-ment along the Umgeni River which is the main source ofwater to Durban City in KwaZulu-Natal, South Africa.Samples were analysed using high-performance liquid chro-matography coupled to a mass spectrometer (HPLC-MS/MS)after clean up and pre-concentration by solid phase extraction(SPE). At the wastewater treatment plant outlet, the antipyreticibuprofen was detected in concentrations up to 12.94μg/Land 15.96 ng/g in wastewater and bio-solids, respectively.The antipsychotic clozapine was detected in concentrationsup to 14.43μg/L and 18.75 ng/g in wastewater and bio-solids,respectively. Other pharmaceuticals namely sulfamethazine,sulfamethoxazole, erythromycin, metronidazole, trimetho-prim, acetaminophen, caffeine and carbamazepine were alsodetected but in lower concentration compared to clozapineand ibuprofen (<10μg/L or 10 ng/g). Clozapine and ibuprofenwere detected at high concentrations in the surface water andsediment of Umgeni River. The highest concentration of clo-zapine (78.33μg/L) was detected at the business park, whilethat for ibuprofen (62.0μg/L) was detected at the point where a tributary, Msunduzi, joins Umgeni. Metronidazole was onlydetected in sediment, and caffeine (2243.52 ng/g) was detect-ed at the highest concentration in the sediment at the bluelagoon sampling site. The antibiotic sulfamethoxazole wasalso detected in appreciable amounts up to 507.34 ng/g inthe sediment at the Msunduzi tributary sampling site. The datacollected implies that while insufficiently treated wastewatercontributes to surface water contamination, human activitiesalso contribute appreciably to the pharmaceutical loading ofRiver Umgeni