1,721,045 research outputs found
Acute toxicity test of leachates from traditional and sustainable landfills using luminescent bacteria
No full textTests for the evaluation of ammonium attenuation in MSW landfill leachate by adsorption into bentonite in a landfill liner
No full textUncontrolled leachate emissions are one of the key factors in the environmental impact of municipal solid waste (MSW) landfills. The concentration of ammonium, given the anaerobic conditions in traditional landfills, can remain significantly high for a very long period of time, as degradation does not take place and volatilisation is not significant (the pH is not high enough to considerably shift the equilibrium towards un-ionised ammonia).
Recent years have witnessed a continuous enhancement of landfill technology in order to minimize uncontrolled emissions into the environment; bottom lining systems have been improved and more attention has been devoted to the study of the attenuation of the different chemicals in leachate in case of migration through the mineral barrier.
Different natural materials have been considered for use as components of landfill liners in the last years and tested in order to evaluate the performance of the different alternatives. Among those materials, bentonite is often used, coupled with other materials in two different ways: in addition to in situ soil or in geocomposite clay liner (GCL).
A lab-scale test was carried out in order to further investigate the influence of bentonite on the attenuation of ammonium in leachate passing through a landfill liner. Two different tests were conducted: a standardized batch test with pulverized bentonite and a batch test with compacted bentonite. The latter was proposed in order to better simulate the real conditions in a landfill liner.
The two tests produced values for the partition coefficient K-d higher than the average measured for other natural materials usually utilized as components of landfill liners. Moreover, the two tests showed similar results, thus providing a further validation of the suitability of the standard batch test with pulverized bentonite.
A thorough knowledge of attenuation processes of ammonium in landfill liners is the basis for the application of risk analysis models for the evaluation of the failure of bottom liners or their components
Problematiche di post-gestione delle discariche per rifiuti solidi urbani
No full textLa discarica controllata è un’opera ineludibile in qualsiasi strategia di smaltimento dei rifiuti solidi urbani. Grazie alla normativa e al progresso tecnico-scientifico degli ultimi anni, si sono fatti passi avanti nella definizione ed applicazione di metodi diversi di gestione della discarica stessa, ma il problema della post gestione rimane comunque un problema di notevoli dimensioni. La normativa italiana fissa in 30 anni la fase controllata di post-esercizio, tuttavia, i limiti di emissioni dopo questo periodo, difficilmente raggiungono obiettivi di qualità accettabili per l’ambiente. Questo è vero, soprattutto, per il flusso del percolato che può fuoriuscire in modo incontrollato dalle barriere di fondo e laterali della discarica. Nasce, pertanto, la necessità di impostare la gestione del post-esercizio secondo una nuova metodologia che ne fissi il termine sulla base del raggiungimento di uno stato dei rifiuti che garantisca un livello accettabile di emissioni. In questo modo, si potrà favorire un modello nuovo di discarica sostenibile che preveda strategie per accelerare la mineralizzazione dei rifiut
Optimization of hydrogen production from food waste using anaerobic mixed cultures pretreated with waste frying oil
No full textSustainable Management of Digestate from the Organic Fraction of Municipal Solid Waste and Food Waste Under the Concepts of Back to Earth Alternatives and Circular Economy
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Development of a two stage liability allocation process in case of multiple party pollution
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Stabilization of solid digestate and nitrogen removal from mature leachate in landfill simulation bioreactors packed with aged refuse
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