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Problem statement: Natural weathering is the most economic method of treatment in order to reduce the release of heavy metals present in the residue. Approach: The aim of the study was to optimize the minimum weathering times that were useful to reduce the lead release to within the Italian limits for landfill disposal. The mechanism of short-term weathering of MSWI bottom ash had been studied and its effect on the leaching of lead had been evaluated. Two bottom ash heaps had been realized for the experimental assessment: In one case an open-air situation was used, in the other, a heap placed under shelter was not exposed to rain. Results: The weathering course was monitored through the results of a leaching test that was carried out at different ageing times (EN 12457-2:2002). The total carbonates were also measured, at the same time, on the fine fraction of the weathered bottom ash ( Key words: MSWI bottom ash, weathering, carbonation, lead release, leaching, INTRODUCTION MSWI Bottom Ash (BA) can be used as secondary building material, in road sub-bases, in the construction of embankments and in other civil engineering applications as an alternative to [...]

The non-point hydraulic and nitrogen loads in the stretch of Po river upstream and downstream from the city of Turin have been investigated, on the basis of regular data concerning quality and flow rates in the river in different periods of a reference year. The collected data have been organized in terms of hydraulic and mass balances, taking into account input points, affluents and withdrawals, and the missing terms as concern non-point loads or transfer phenomena with surrounding banks and connected aquifers have been identified.From the nitrogen speciation it was possible to distinguish between different contributions to river load, and to estimate presence of agricultural loads, run-off phenomena from impervious urban areas, aquifer connections. All these information can be useful for a better assessment of the surrounding territory in order to improve river quality for different uses. Keywords: River model, nitrogen balance, non-point sources, sampling, river quality, INTRODUCTION In the treatment plant of the city of Turin (SMAT plant) the city wastewater (one million inhabitants) and a high number of surrounding communities are treated; the treated flow [...]