Report on the characterization of treated sediments"

The deliverable presents the results of the activities related to SUBSED Action C1 from 01/01/2019 until 30/06/2019, as planned, concerning the sediment characterization during the landfarming process. It can be concluded that three months landfarming process was effective in homogenizing the substrate and further reducing organic contamination, and in reaching physical and chemical characteristics in accordance with the Italian regulation for agronomic substrates (D.lgs. 75/2010) with the only exception of organic carbon and bulk density (Table 3). The bulk density was, in fact, slightly higher than the maximum limit, while the organic carbon was lower. Nevertheless, in order to reach the C concentration and bulk density required by Italian legislation, it would be sufficient to mix the sediments with a source of organic matter rich in carbon and with low bulk density such as peat, sludge or coconut fiber. Regarding the inorganic contaminants (heavy metals), normed by D.lgs. 75/2010, all the metals in the sediments at the end of the landfarming process showed a concentration considerably lower than the legal limits. A great reduction of heavy hydrocarbons (C> 12) was observed during the landfarming process, resulting lower than the quantification limits (100 mg/kg). Instead, a significant variation was not recorded at the end of the process for the PAHs (table 2), probably due to their more recalcitrant form. However, this residual contamination seems to not compromise the reuse of the sediments in horticulture, since the toxicological tests showed no phyto toxicity of the sediments (Fig. 8).