Containment of heavy metals in landfills with leachate recycle

The presence, transport, and ultimate fate of heavy metals in landfill leachate are discussed. The influence of chemical activity and complexation on the behavior of metals in such environments is investigated. Leachates generated in experiments had high concentrations of dissolved ions and organic and inorganic ligands. These substances favored the removal of heavy metals primarily by precipitation as sulfides. This removal was enhanced by the increased stabilization rates and filtering action promoted by the recirculation of leachate through the landfill mass. (1 diagram, 13 graphs, 15 references, 2 tables)