The use of sequential extraction to evaluate the remediation potential of eavy metals frp, contaminated harbour sediment

In this work sequential extraction is performed with harbour sediment in order to evaluate the electrodialytic remediation potential for harbour sediments. Sequential extraction was performed on a sample of Norwegian harbour sediment; with the original sediment and after the sediment was treated with acid. The results from the sequential extraction show that 75% Zn and Pb and about 50% Cu are found in the most mobile phases in the original sediment and more than 90% Zn and Pb and 75% Cu are found in the most mobile phase in the sediment treated with acid. Electrodialytic remediation experiments were made. The method uses a low direct current as cleaning agent, removing the heavy metals towards the anode and cathode according to the charge of the heavy metals in the electric field. The electrodialytic experiments show that up to 50% Cu, 85% Zn and 60% Pb can be removed after 20 days. Thus, there is still a potential for a higher removal, with some changes in the experimental set-up and longer remediation time. The experiments show that thc use of sequential extraction can be used to predict the electrodialytic remediation potential for harbour sediments

Gårdsjön Status Report for 1991-1992: The first Year of Treatment

Nitrogen addition weekly to catchment G2 at Gårdsjön began April 1991. During the first year of treatment a total of 230 meq/m²yr NH4No3 was added in 33 mm of water plus 90 meq/m²/yr deposited in 631 mm throughfall. Runoff contained significantly higher concentrations of No3 (but not NH4) beginning in November 1991. No respons was seen during the growing season. None of the other components and processes (soil solution, mineralization, fine-roots, mycorrhiza and vegetation) studied as part of NITREX showed significant response during the first year of treatment