ABSTRACT
It is well established, that trace elements can be incorporated into sulfidic minerals, such as pyrite, and that diese trace elements can be released to the groundwater, when oxidation of the host minerals takes place. However, less attention has been paid to the fact that trace elements can be build into reaction products, such as iron or manganese oxy-hydroxides. This secondary pool of trace elements can be very mobile when changes take place in the overall water chemistry. Such changes in the water chemistry could for example be triggered by fluctuations in the water table. A sandy aquifer has been studied where high concentrations of trace elements, in particular Ni, has been observed after the water table was raised by artificial recharge.
