Abstract:

: Acid mine drainage originates from mining waste, tailings and overburden being exposed to air and water; it is also observed in abandoned mines, characterized by high acidity and increased concentrations of sulfate and heavy metals. It is considered a notorious pollutant, mostly affecting superficial and ground water quality. Until 1977, Lavrion mines have been the heart of dynamic Greek mining and extractive metallurgy. The present paper discusses the possibility of using low-cost eco-friendly materials, i.e., natural and synthetic zeolites for the in situ rehabilitation of Lavrion mine soil. Na-P1 synthetic zeolite prepared from Meliti fly ash and two natural zeolites from Samos tuffs mostly containing clinoptilolite and mordenite, respectively, were employed. The results indicated that all three aluminosilicates alleviated two basic soil parameters closely correlated with fertility, i.e., high acidity and low CEC. Regarding toxic metals leaching, Na-P1 synthetic zeolite proved more efficient, reducing heavy metal contents in the leachates by 38%, 72%, 61%, 67%, 77% and 33% for Pb, Cd, Zn, Cu, Mn and Fe, respectively. This was attributed to both the increased pH and CEC values of the Na-P1 zeolite. Between the Samos zeolites, the richest in mordenite exhibited the better performance.

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