1,721,133 research outputs found
Sinterizzazione delle ceneri volanti da impianti di incenerimento di Rsu
No full textIl manoscritto contiene i risultati ottenuti nel corso di una campagna sperimentale per la valutazione della applicabilità di un trattamento di sinterizzazione delle ceneri volanti provenienti dalla termovalorizzazione dei rifiuti urbani. Quale additivo del processo termico di sinterizzazione è stato impiegato polverino da carbone, in modo da ottenere uno schema di processo basato sul co-trattamento di più residui di origine industriale.
I prodotti del trattamento sono stati caratterizzati in termini di comportamento ambientale e caratteristiche fisiche e meccaniche, con particolare riferimento alle proprietà che ne condizionano il reimpiego nei settori dell'ingegneria civile
Enhancing waste-to-energy bottom ash reactivity in the perspective of utilization or disposal
No full text
The leaching behavior of incinerator bottom ash as affected by accelerated ageing
No full textDifferent artificial ageing treatments were applied to fresh incinerator bottom ash with the aim of promoting/accelerating the natural reactions occurring over time on the mineral phases in the material. The weathering treatments included accelerated carbonation, treatment with air and treatment with nitrogen gas. Both fresh and treated bottom ashes were characterized for their mineralogical composition, acid neutralization capacity and leaching behavior of metals. The results were compared to those obtained from similar characterization of bottom ash samples weathered under atmospheric conditions for 4 years. The findings from the experimental campaign indicated that both the release of metals and the type of solubility-controlling solid phases varied as a function of the duration and type of ageing treatment. The most appreciable influence on mineralogy, acid neutralization behavior and metal leaching was observed for the 48 h carbonation treatment. It was also observed that 4-day aeration of bottom ash was capable of producing similar buffering behavior to that displayed by naturally aged bottom ash. (C) 2004 Published by Elsevier B.V
Modelling heavy metal and anion effects on physical and mechanical properties of Portland cement by means of factorial experiments
No full textThe aim of the present work was to investigate the influence of a number of heavy metals (Cd, Cr(III), Cu, Pb and Zn), as well as anions (Cl-, SO42-) on the physical and mechanical properties of cementitious pastes, including setting time, bulk density and unconfined compressive strength. The above mentioned species and their concentrations were selected in order to simulate addition of 20% municipal solid waste incinerator ash to Portland cement. Spiking experiments were performed according to a 2(IV)(7-3) fractional factorial design by addition of pure compounds containing the contaminants of interest to Portland cement. The results from the experimental campaign, which were interpreted using statistical analysis techniques, showed that the investigated contaminants variously affected the hydration process of cement. The ranking for final setting time values was Zn(NO3)(2) > K2SO4 > NaCl > mean response > Cr(NO3)(3) > NaCl+Cr(NO3)(3), Cd(NO3)(2)+Pb(NO3), or CuCl2+Zn(NO3)(2) interaction, whereas the ranking for UCS values during hardening was Zn(NO3)(2) > CuCl2 > NaCl+K2SO4, CuCl2+Pb(NO3)(2) or Cd(NW,+Zn(NO3)(2) interaction > mean response. Conversely, none of the selected contaminants was found to significantly influence ultimate strength
Energia dalla spazzatura, le buone pratiche in Europa
No full textIl presente lavoro illustra le buone pratiche della gestione dei rifiuti sulla base della analisi dei più recenti sviluppi normativi, dello stato di diffusione ed applicazione delle diverse tecnologie e dei più recenti sviluppi nel settore della gestione e del trattamento dei residui. Le diverse opzioni di gestioni vengono poste a confronto in termini di prestazioni tecniche, economiche ed ambientale, prediligendo scenari di integrazione tra diverse soluzioni tecnologiche tra loro complementari
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