Temporal dynamics of pore water concentrations of Cd, Co, Cu, Ni, and Zn and their controlling factors in a contaminated floodplain soil assessed by undisturbed groundwater lysimeters.

We aimed to assess the dynamics of pore water concentrations of Cd, Co, Cu, Ni, Zn and their controlling factors (EH, pH, DOC, Fe, Mn, and SO4(2-)) in a contaminated floodplain soil under different flood-dry-cycles. Two parallel undisturbed groundwater lysimeters (mean values presented) were used for long term (LT; 94 days) and short term (ST; 21 days) flood-dry-cycles. Reducing conditions under LT lead to low EH and pH, while DOC, Co, Fe, Mn, and Ni increased. Cadmium, Cu, Zn, and SO4(2-) increased under oxidizing conditions during ST. Cobalt and Ni revealed a similar behavior which seem to governed by EH/pH, Mn, Fe, and DOC. Cadmium, Cu, and Zn reveal a similar fate; their dynamics were affected by EH/pH, DOC, and SO4(2-). Our findings suggest that a release of Cd, Cu, Co, Fe, Mn, Ni, and Zn under different flood-dry-cycles can assumed what might create potential environmental risks in using metal-enriched floodplain soils.