SEASONAL-VARIATION OF METAL CONTAMINATION OF RIVERINE SEDIMENTS BELOWA COPPER AND SULFUR MINE IN SOUTH-EAST IRELAND

The discharge of acid mine drainage (AMD) from the abandoned sulphur a nd copper mines at Avoca (S.E. Ireland) results in the formation of oc hreous deposits on the river substrate. Sediment sampling was carried out intensively during June and August, 1994 and again during March an d April, 1995 to investigate seasonal variation of Fe, Cu and Zn conce ntration in riverine sediments of the receiving water (Avoca River). T emporal and spatial variations indicate that, apart from pH, hydrologi cal Factors play a major role in metal accumulation of highly energeti c river systems. Zinc adsorption and desorption of 'ochre' is chiefly regulated by pH, while Cu removal seems to be primarily by co-precipit ation with iron. Basic considerations with regard to sampling techniqu es are discussed. Copyright (C) 1996 IAWQ.