ASSESSMENT OF THE LEACHING BEHAVIOUR OF TREATED BIOWASTE: COMPARISON BETWEEN COMPOST AND MECHANICALLY-BIOLOGICALLY TREATED MSW

摘要

This work aimed at evaluating and comparing the leaching behaviour of two types of treated biowastes produced in the city of Rome from composting and Mechanical-Biological Treatment (MBT) plants, respectively. To this end, batch and column leaching tests were performed. The obtained results revealed a similar leaching behaviour for the two materials although, as expected, the cumulative release of metals was markedly lower in compost than in MBT wastes. Furthermore, for both the investigated biowastes, it was observed an evident similarity between the leaching pattern of the dissolved organic carbon (DOC) and the one observed for some of the investigated metals. Hence, results from the leaching tests were used in order to derive specific correlation coefficients between the DOC and metals. These correlation coefficients were then integrated in a simplistic model for the cumulative release of DOC, allowing to describe the release of metals as a function of the L/S ratios. The comparison with the experimental data from the different column tests highlighted that the screening model proposed replicates quite well the leaching trend observed for most of the selected metals.