Sorption and leaching characteristics of heavy metals in artificial soil

The objective of this study was to investigate the heavy metal sorption and leaching characteristics of an “artificial soil” formed by blending industrial and municipal by-products and implemented as a beneficial waste reuse and land reclamation strategy. Two primary tasks were undertaken in order to complete this objective: (1) a background study including a review of literature dealing with heavy metal mobility within different artificial soil mixes and biosolids-amended soils, and (2) a laboratory investigation of the general engineering, sorptive, and leaching properties of an artificial soil comprising yard waste, biosolids, cement kiln dust (CKD) and coal ash. The background literature review shows that previous artificial and biosolidsamended soil mixes have been very effective in immobilizing heavy metals. Use of biosolids-amended soils for agricultural applications results in a substantial increase in crop yield and size. The organic biosolids and mineral faction of artificial soil mixtures help in immobilizing heavy metals present in the aqueous phase. Materials for laboratory testing were sampled from a full-scale artificial soil emplacement being implemented as an alternative evapotranspirative (ET) cover system in Hannibal, Missouri (Bobba, 2005; Bobba et al., 2006, Wayllace and Likos, 2006). Materials at the site include an organic-rich O-horizon (yard waste and biosolids) overlying a mineral-rich C-horizon (CKD and coal ash) to simulate a natural residual soil profile. The laboratory investigation consisted of testing for natural (in-situ) moisture