POLLUTION OF 2 SOILS BY ARSENIC, CHROMIUM AND COPPER, DENMARK

High concentrations of chromium, arsenic and copper due to spills of chemicals used in impregnating wood have been investigated in two soils that are representative of Spodosols and Alfisols in glacial outwash and loamy till, respectively. Methods of investigation include field observations, laboratory analyses of samples and some micromorphological observations. The results indicate that the three elements bind to organic matter. Chromium is so strongly bound that elevated concentrations are not detected below the A horizons. In the B and C horizons arsenic and copper are associated with oxides of iron, aluminium and manganese. In the Alfisol much of the copper is retained in the calcareous part of the profile as small spheres of precipitated malachite. In this profile differences in retention of copper are also associated with changes in permeability. High concentrations of sodium and potassium introduced with the impregnation solution have changed the balance between basic cations bound in the exchange complex to high proportions of the monovalent ions, whereas chromium and copper are not bound in an exchangeable form to a measurable extent.