Fenton-like treatment of contaminated sediments: Influence on organic matter content and heavy metal mobilization

This study presents the results of laboratory scale experimental Fentonlike treatments conducted on marine sediment slurries. The sediment was collected in a harbor situated in a high density industrial area, characterized by a high pollution levels of hydrocarbons and was not artificially contaminated. As the conditions generated during the treatment of the organic contamination may change the redox potential of the sediment, an evaluation of some heavy metal mobilization was also performed. The investigated parameters were: the H2O2 dose and the effect of a phosphate salt addition. To evaluate sediment’s characteristics COD, TGA and DTA under O2 atmosphere analyses were performed while TOC, COD, pH and Eh were measured on the liquid. Heavy metal mobilization was monitored through atomic absorption spectrometry of the liquid. Results indicate that the treatment was able to change the organic matter to a less hydrophobic state, to destroy part of the carbon and to lower the COD of the sediment. In addition the treated sediment showed easier-to handle characteristics, reduced caking and lower aggregation capacity. However some mobilization of Cu and Zn occurred while the concentration of Fe lowered.