Adsorption of Copper, Zinc, and Cadmium by a Forest Soil

Abstract

Time‐dependent batch equilibrium studies for Cu, Zn, and Cd were conducted to determine the sorbing properties for these metals on the upper 30 cm of a forest soil. Major cations were added to equilibrating solutions in an attempt to match to cationic matrix of a sewage sludge. Essentially all of the Cu was adsorbed by the soil in the first 0.3 hour of equilibration. Copper adsorption data fit the Freundlich isotherm better than the Langmuir isotherm. Adsorption of Zn and Cd was more time dependent than Cu, especially for the 0–7.5 cm depth of soil, and was described with some success by the empirical kinetic equation, ∂S/∂t = aCbSc, where S is µg metal absorbed per g soil, C is concentration of metal in final equilibrating solution, t is time, and a, b, and c are constants. Batch data taken at 3 hours of equilibration for Zn and Cd also fit the Freundlich isotherm better than the Langmuir isotherm. For Cu, Zn, and Cd adsorption, Freundlich constants (K) were higher for the 0–7.5 cm depth than for the 7.5–15 cm depth, indicating the binding effects of the higher level of organic matter in the surface 7.5 cm of forest soil.

Mobility of heavy metals in poorly developed carbonate soils in the Mediterranean region

“…However, Amarcher et al (1986) were not able to correlate the retention of Cd, Cu, Zn and Pb with iron oxide content. Sidle and Kardos (1997) found a correlation between Cd retention and organic matter content while Harter (1983) could not tie total organic matter content to metal sorption.…”

The Use of Adsorption Equations to Describe Copper Complexing by Humified Organic Matter

“…Others (e.g. Heydemann, 1959; Sidle and Kardos, 1977) have found that their data fitted Freundlich isotherms more closely than Langmuir isotherms. Zunino and Martin (1977) used the concept of an adsorption isotherm in their studies of copper complexing by colloidal organic matter.…”

Influence of pH on Soil Charge Characteristics and Cadmium Sorption in Some Noncontaminated Soils of Indian Subtropics

“…Anthropogenic sources comprise contributions made by mankind including industrial processes that contribute to both atmospheric and land depositions, mining and metallurgy, urban and industrial wastage, and sewage and fertilizer applications [4]. Soil characteristics positively correlated with Cd retention are pH [5], organic matter (OM) content, cation exchange capacity (CEC) [6], and specific surface area (SSA) [7], while free iron oxides are negatively correlated [8].…”