Occurrence and significance of polychlorinated biphenylsin water, sediment pore water and surface sedimentsof Umgeni River, KwaZulu-Natal, South Africa

Abstract

The Umgeni River is one of the main sourcesof water in KwaZulu-Natal, South Africa; however;there is currently a lack of information on the presenceand distribution of polychlorinated biphenyls (PCBs) inits sediment, sediment pore water and surface water.This study aims to determine the occurrence and signif-icance of selected PCBs in the surface water, sedimentpore water and surface sediment samples from theUmgeni River. Liquid-liquid and soxhlet extractionswere used for water or pore water, and sediments, re-spectively. Extracts were cleaned up using a florisilcolumnandanalysedbygaschromatography-massspectrometry. The total concentrations of eightpolychlorinated biphenyls were 6.91–21.69 ng/mL,40.67–252.30 ng/mL and 102.60–427.80 ng/g (dryweight), in unfiltered surface water, unfiltered sedimentpore water and surface sediments, respectively. Thepercentage contributions of various matrices were 4,36 and 60 % for unfiltered surface water, unfiltered porewater and sediment, respectively. The highest concen-trations of PCBs were found in water, pore water and sediment collected from sampling sites close to theNorthern Wastewater Treatment Works. The highestchlorinated biphenyl, PCB 180, was the most abundantat almost all sampling sites. To our knowledge, this isthe first report on occurrence of polychlorinated biphe-nyls in the Umgeni River water, pore water and sedi-ment system and our results provide valuable informa-tion regarding the partitioning of the PCBs between thewater and sediment systems as well as the organicchemical quality of the water.