Sorption behavior of copper, zinc, and cadmium in response to simulated changes in soil properties

Abstract

Environmental changes and management practices which alter soil properties may affect the capacity of soils to sorb trace metals, such as copper (Cu), zinc (Zn), and cadmium (Cd), and thus influence the bioavailability and leach ability of the metals. Two agricultural soils were treated to partially oxidize organic matter and to decrease soil pH for evaluating the effects of acidification and organic matter oxidation on trace metal sorption onto soils. For the one soil with a pH value of 6.74 and organic carbon (C) content of 46.9 g‐kg‐1, loss of 11% of its organic matter reduced by 97, 72, and 62% the original sorption capacity for Cu, Zn, and Cd, respectively, while the corresponding values caused by acidifying the soil one pH‐unit were 32, 16, and 29%. For the another soil with a pH of 4.69 and organic C content of 16.3 g‐kg‐1, a decrease in pH by one unit resulted in a loss of 43, 21, and 52% of the sorption capacity for Cu, Zn, and Cd, respectively.