Temporal variation of trace elements in waters polluted by municipal solid waste landfill leachate.

Landfill leachate-polluted stream waters were monitored in three sampling campaigns (November 2001 to June 2006), with emphasis on trace elements. The data were evaluated by means of statistics and speciation modelling. Two statistically different groups of trace elements were distinguished: (1) Ba, Sr, Al, Fe, Mn, Cr, Co, Ni, V, As, Se, Sb, U, Li, Rb and Cs decrease during the rain event due to dilution; (2) Pb, Zn, Cu and Cd increase during the rain event due to the dissolution of hydrous ferric oxides and calcite, on whose surfaces these elements are bound, mainly in the stream sediments downgradient to the landfill.