Reclamation of Pb/Zn smelter wastes in Upper Silesia, Poland.

Waelz and Doerschel process Pb/Zn smelter wastes, dumped in uncontrolled piles in Silesia, were stabilised in the summer of 1994 by application of heavy loads of CaCO3 (30 tonnes/ha), CaO (1.5-15 t/ha) and municipal biosolids (150-300 t/ha), followed by seeding with a mixture of acid- and salt-tolerant grass species selected in a small-plot experiment. Vegetation was successfully established on 85% of the Waelz material demonstration plot area, even though it was initially high in water-soluble Zn, Pb, and Cd. Revegetation of much of the Doerschel material area failed initially because of extremely high salinity, high content of water soluble metals (Cd in particular), and heavy compaction. The area was capped with waste lime and re-treated with biosolids (300 t/ha) in 1995. The observed plant response to biosolids and lime indicates this approach to be an environmentally beneficial technology as compared with the traditional methods utilising topsoil covers.
Waelz and Doerschel process Pb/Zn smelter wastes, dumped in uncontrolled piles in Silesia, were stabilised in the summer of 1994 by application of heavy loads of CaCO3 (30 tonnes/ha), CaO (1.5-15 t/ha) and municipal biosolids (150-300 t/ha), followed by seeding with a mixture of acid- and salt-tolerant grass species selected in a small-plot experiment. Vegetation was successfully established on 85% of the Waelz material demonstration plot area, even though it was initially high in water-soluble Zn, Pb, and Cd. Revegetation of much of the Doerschel material area failed initially because of extremely high salinity, high content of water soluble metals (Cd in particular), and heavy compaction. The area was capped with waste lime and re-treated with biosolids (300 t/ha) in 1995. The observed plant response to biosolids and lime indicates this approach to be an environmentally beneficial technology as compared with the traditional methods utilising topsoil covers.