HEAVY-METALS IN THE ENVIRONMENT - MOBILITY OF HEAVY-METALS IN URBAN WASTE-AMENDED SOILS

A soil column study was conducted to assess the vertical movement of certain heavy metals in soils amended with urban waste compost (90 t ha-1). The effect of the complexing capacity of water soluble organic matter from compost on metal mobility has been previously reported. The results of this investigation demonstrate the enhanced levels of Cu, Zn, Ni, and Cr eluted from 50-cm soil columns when compost is added to a Fluventic Xerochrept clay-loamy, mixed, mesic and a Typic Xerochrept, fine sandy-loamy, mixed, mesic. The increase in these metal concentrations is greater in sandy-loam soil than in clay-loam. The water soluble organic fraction of the compost has minimal impact on the metals concentration. Seventy to eighty percent of the water-soluble organic fraction was retained in the upper 10-cm layer of soils, with only 5% eluted from clay-loam soil and 10% from the sandy-loam.