Heavy Metals Transport Model in a Sludge‐treated Soil

Abstract

AbstractA transport model was developed to study the movement of Cu, Zn, and Cd in a forest soil. Adsorption of cationic forms of these metals by the soil was described by Freundlich adsorption isotherms. Two slug inputs of heavy metals were introduced during the first 37 days and between the 168th and 196th days of the 17‐ month simulation period. The transport model based on the adsorption of cationic forms of Cu, Zn, and Cd severely underpredicted the movement of these metals in both the 15‐ and 120‐cm percolate when compared to previously observed field data. With the addition of assumed levels of less highly adsorbed chelated components to the model, percolate metal concentrations were roughly predicted at the 15‐cm depth. However, data generated by the partitioned (chelate component) model also underpredicted movement of heavy metals to the 120‐cm depth, indicating that transport processes other than accelerated movement of chelated compounds, such as “channelization”, may be involved in the field.