61 research outputs found
Treated Acid Mine Drainage and Stream Recovery: Downstream Impacts on Benthic Macroinvertebrate Communities in Relation to Multispecies Toxicity Bioassays
Research ArticleThe success and long term effectiveness of extensive and expensive engineering solutions to restore streams
impacted by Acid Mine Drainage (AMD) is rarely tested. Concentrations of pollutants were measured in water
along a longitudinal gradient from a stretch of the Tweelopie stream, South Africa, that receives pH-treated acid
mine drainage (AMD) from an abandoned gold mine. The biotoxic effects of treated AMD were determined
through macroinvertebrate biotic indices (SASS5) and a battery of toxicity bioassays. These included the L.
sativa, A. cepa, D. magna toxicity and Ames mutagenicity tests, as well as an in vitro human liver cancer cell line
HepG2. Even though the Tweelopie stream was moderately to severely degraded by multiple anthropogenic
stressors, the impact of the treated AMD was masked by the improvement in the system downstream after mixing
with the domestic wastewater effluent receiving stream, and subsequent further dilution as a result of the karst
springs downstream. The general improvement of the system downstream was clearly shown by the decrease in
the ecotoxicity and mutagenicity in relation to the in-stream macroinvertebrates. PCA multivariate analysis
successfully displayed associations between the different environmental variables and the decrease in toxicity
and subsequent ecosystem improvement downstream. This study indicated that environmental management of
AMD remediation should consider long term assessment strategies, including multiple factors, to promote biological
ecosystem recovery
Application of multi‑method approach to assess groundwater–surface water interactions, for catchment management
Globally, the dependence of river systems to delayed discharge of subsurface water to augment flows during dry seasons is well documented. Discharge of fresh subsurface water can dilute concentrated river flow quality during reduced flow. Observed and reported results on the Berg River’s declining water quantity and quality are a concern to the regions socio-economic growth and environmental integrity. Understanding the role of subsurface water discharges on the quantity and quality of receiving surface water courses can improve their management during dry periods. A case study was designed and implemented in the upper Berg River catchment in the Western Cape Province of South Africa to assess the influence of groundwater–surface water interaction on water quantity and quality. This study aimed to quantify and characterize the quality of subsurface water available in the upper catchment to improve observed declining water quality downstream. Hydrograph separation provided estimates of water fluxes during 2012–2014 low and high flow periods, while hydrochemical analysis provided insights on impacts of major land use activity in this catchment on water resources. Hydrograph separation analysis indicated that the Berg River is 37.9% dependent on subsurface water discharges annually. Dominant Na–Cl-type water indicates the quality of water from the upper Berg River is largely affected by natural processes including short residence times of aquifer water, rock–water interactions and atmospheric deposition of NaCl ions. These results provide insights for suggesting management options to be implemented to protect subsurface water for continued dilution and water resources management in the lower catchments
Recommended from our members
Contrasting assigned expatriates and self-initiated expatriates: a review of extant research and a future research agenda
The bioavailability and toxicity of ZnO and Ni nanoparticles and their bulk counterparts in different sediments
Development of a rapid and sensitive battery of bioassays for risk assessment of cyanobacterial microcystin-LR in drinking water of rural water treatment plants, South Africa
No Abstrqac
An ecotoxicological screening tool to prioritise acid mine drainage impacted streams for future restoration
Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)AgriwetenskappeGenetik
- …