Assessment of Emerging Organic Contaminants as Tracers of Surface Water and Groundwater Ingress into Mine Voids in Gauteng, South Africa
摘要
Studies about the occurrence and behaviour of emerging organic contaminants (EOCs) in African groundwater are limited, while those in mine water are limited worldwide. The current study explores the occurrence and distribution of EOCs and their use as tracers of surface water and groundwater ingress into mine voids at Springs, South Africa. Nine surface water, 16 boreholes, and 6 mine shafts were sampled during the wet and dry seasons for the analyses of pharmaceuticals, pesticides, hormones, industrial and lifestyle compounds. Sulfamethoxazole, carbamazepine, pesticides, caffeine, and bisphenol A were detected in 100% of surface and groundwater sites, especially during the wet season. Bisphenol A and caffeine were further detected in all the mine voids, while hormones were not detected. Higher concentrations were measured during the dry season and was attributed to the influence of the first rainfall flush or evaporation. The low concentrations during the wet season were associated with dilution. The occurrence and spatial distribution of EOCs was generally not confined to specific land use areas suggesting mixing of contaminants from different sources. However, high bisphenol A concentrations (maximum of 6.6 µg/L) were detected in the vicinity of industrial and mine tailings processing activities. Higher EOCs were measured in surface water than groundwater and mine water, while mine water contained concentrations higher than those in groundwater. The findings indicate that surface water is the main source of ingress into the mine voids. This approach can be used to map sources of ingress, which is important for mine water management.