Effect of modified Fenton treatment on the thermal behavior of contaminated harbor sediments

This study presents the results of experimental Fenton-like treatments conducted on marine sediment slurries (2 g sediment vs. 20 nil liquid). The sediment was collected in a harbor situated in a high density industrial area, characterized by a great hydrocarbon C > 12 and PAHs contamination. The investigated parameters were: the H2O2 dose, the reagent's pH and the effect of a phosphate salt and ferrous iron addition. To evaluate sediment's characteristics COD, particle size, thermogravimetric and differential thermal analyses were performed under N-2 and O-2 atmosphere while dissolved organic carbon and COD analyses were performed on the filtrate. Results indicate that the treatment was able to change the organic matter to a less hydrophobic state, to destroy part of the organic carbon (up to 78% decrease of the 200-400 degrees C labile organic matter), to lower the COD of the sediment (60% COD removal maximum) and to increase the cumulated distribution undersize. In addition as the treated sediment showed easier-to-handle characteristics, reduced caking and lower aggregation capacity, the modified Fenton treatment could also be considered a pre-treatment of a successive thermal treatment. (C) 2007 Elsevier Ltd. All rights reserved.