Response of the sorption behavior of Cu, Cd, and Zn to different soil management

Weinheim

2006

2 Abb., 49 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

4181

200129935

This study investigated the effect of different farming practices over long time periods on the sorption-desorption behavior of Cu, Cd, and Zn in soils. Various amendments in a long-term field experiment over 44 y altered the chemical and physical properties of the soil. Adsorption isotherms obtained from batch sorption experiments with Cu, Cd, and Zn were well described by Freundlich equations for adsorption and desorption. The data showed that Cu was adsorbed in high amounts, followed by Zn and Cd. In most treatments, Cd ions were more weakly sorbed than Cu or Zn. Generally, adsorption coefficients KF increased among the investigated farming practices in the following order: sewage sludge fallow < inorganic fertilizer without N green manure < peat < Ca(NO3)2 < animal manure grassland/extensive pasture. The impact of different soil management on the sorption properties of agricultural soils for trace metals was quantified. Results demonstrated that the soil pH was the main factor controlling the behavior of heavy metals in soil altered through management. Furthermore, the constants KF and n of isotherms obtained from the experiments significantly correlated with the amount of solid and water-soluble organic carbon (WSOC) in the soils. Higher soil pH and higher contents of soil organic carbon led to higher adsorption. Carboxyl and carbonyl groups as well as WSOC significantly influenced the sorption behavior of heavy metals in soils with similar mineral soil constituents.