Mobility of zinc and copper in contaminated clay soil influenced by Actinidia deliciosa and incubation times

As a low cost byproduct, Actinidia deliciosa shell can be made into sorbent materials which are used in heavy metals immobilization. It has been investigated as a replacement for currently expensive methods of heavy metal immobilization from soil. In this study, soil samples were contaminated with copper (Cu) and zinc (Zn) at the rate of 600 ppm in separate dishes. The 5% Actinidia deliciosa shell was added into the samples. The samples were incubated for 3 hours, and 1, 3, 7, 14, 21, and 28 days at 28° C with constant moisture. After incubation, metals in contaminated soil with Actinidia deliciosa shell and control soils were fractionated by the sequential extraction procedure. The results of this study indicated that addition of Actinidia deliciosa shell led to increased organic matter fraction and stabilized Cu and Zn in contaminated soil. In the control soils, the dominating chemical form for Zn and Cu were Fe-Mn oxides and residual, respectively. Sequential extraction also revealed that the addition of Actinidia deliciosa decreased the easily accessible fraction of Zn through the transformation into less accessible fractions. The experiment was performed in three replicates and two treatments.