Miscible Displacement of Zn In Soil Columns: Influence of Phosphate.

Transport of heavy metal such as zinc (Zn) in soils may be affected by several processes including kinetic sorption and release. In this study, the transport of Zn in soil columns for two acidic soils and one neutral soil was investigated. Miscible displacement column experiments were carried to investigate the mobility of Zn in soils.  Breakthrough results indicated that Zn mobility was strongly retarded.  We tested the hypothesis that phosphate additions to soils increases zinc adsorption and consequently limits Zn mobility in soils. For breakthrough curves (BTCs) with a mixed P and Zn pulse, lower Zn concentration were observed in the presence of P indicative of increased Zn sorption. The influence of P was manifested by increased irreversible retention of Zn and little impact on the extent of Zn  in soils.