Spatial and temporal patterns of acidity and heavy metals in predicting the potential for ecological impact on the Le An river polluted by acid mine drainage

Integration and comparison of metal contamination from acid mine drainage and an assessment of the potential for ecological impact was conducted in the aquatic ecosystems of the Le An river. The results indicated low acidity, high levels of suspended solids containing a high content of copper in river water and sediment in the upstream region of the Le An river due to the pollution from the Dexing copper mine, and high concentrations of zinc and copper in surface water and sediments, high release potential and ready bioavailability of heavy metals in sediments downstream (after site A07) due to the pollution from the Jishui river. The pollution from acid mine drainage in the Le An river potentially effects an ecological impact on the aquatic ecosystem, mainly between sites A04 and A08. The management strategy should, therefore be mainly applied to acid mine drainage from the Dexing copper mine and heavy metal discharges from the Jishui river. (C) 1997 Elsevier Science B.V.