Investigation of parameters that can increase the mobility of arsenic in groundwater after soil washing in Gudarp.

After soil washing in the former wood preservation industry, the concentration of As (arsenic) have increased in the groundwater. The purpose of this study was to investigate different parameters that could increase the mobility of As in the groundwater. The impact the soil wash has on the soil and it is effect on mobility will also be consider. This study will also show how As, Cu and Cr changes over time, however, the focus will be on As when the soil washing have been controlled by the As concentration. Soil and groundwater samples have been collected. Through filtration Fe (iron), Al (aluminium) and TOC (Total organic carbon) together with As have been analysed to determine a possible relation. Redox potential and As specification have also been analysed. As occur probably dissolved in the groundwater or together with DOC (Dissolved organic carbon). No link between colloids and complexes with Fe and Al together with As was found through filtration. Redox potential has no impact since the water was well oxygenated and As occurred as As(V). As and Cu follow the same time trend, while different for Cr. It is clear that the concentration of As increased in the groundwater after soil washing and that soil excavating have not the same problem with increased levels. The ground structure is changed and the clay mineral with adsorption surface is removed with soil washing. This could explain the increase of As in the groundwater.