Soil Physicochemical Parameters Affecting Metal Availability in Sludge-Amended Soils

摘要

A series of laboratory studies was conducted to determine the effects of soil pH and redox potential onlevels of trace metals (Cu, Zn, Cd, Pb, Cr, Ni, and As) in selected chemical forms and their availability to plants. This research demonstrates the important effects of soil redox potential conditions in regulating the chemical mobility and plant availability of Zn and Cd, two key contaminants in sludge materials that may be applied to soils. Where alternatives exist for disposal of contaminated sludge, wet or poorly oxidized soils would be more effective in immobilizing Zn and Cd, and application to these soils would result in less accumulation of these metals in most crops or plants in uncultivated habitats. Chemical availability and plant uptake studies under controlled pH and redox potential conditions indicated various organic phases predominant in retaining Cu under reducing conditions.