evaluation of sediments decontamination by chelatingagents using thermogravimetricanalysis

this study investigated single-step extraction of heavy metals from contaminated sedimentscollected in the port of cádiz. experimental tests of washing with an aqueous solution of a chelating agent wereperformed at selected solid/liquid (s/l) ratios. two chelating agents were chosen: 0.3 m edta(ph 3.8 and 8)and sodium citrate (1 m). the objective of the tests was to investigate extractive decontamination by thewashing treatment. the study was focused on the extraction of pb, cu, zn, and cd. the experiments showedthat the decontamination efficiencies of the extractants were of the order: edta (ph 3.8) > edta (ph 8) ~sodium citrate. edtasolution with slightly acid ph was optimal for the extraction of pb, cu, zn and cd. thedata obtained from the thermal analysis of sediments after the decontamination process indicated the successof the extraction procedurewhich is proposed as a technique for controlling the behaviour of the decontaminationprocess.