Search results for "BIODEGRADABILI"

Assessment of landfill leachate biodegradability and treatability by means of allochthonous and autochthonous biomasses

2020

Abstract The biodegradability and treatability of a young (3 years old) municipal landfill leachate was evaluated by means of chemical oxygen demand (COD) fractionation tests, based on respirometric techniques. The tests were performed using two different biomasses: one cultivated from the raw leachate (autochthonous biomass) and the other collected from a conventional municipal wastewater treatment plant after its acclimation to leachate (allochthonous biomass). The long term performances of the two biomasses were also studied. The results demonstrated that the amount of biodegradable COD in the leachate was strictly dependent on the biomass that was used to perform the fractionation tests…

Effect of long residence time and high temperature over anaerobic biodegradation of Scenedesmus microalgae grown in wastewater

2018

[EN] Anaerobic digestion of indigenous Scenedesmus spp. microalgae was studied in continuous lab-scale anaerobic reactors at different temperatures (35 degrees C and 55 degrees C), and sludge retention time - SRT (50 and 70 days). Mesophilic digestion was performed in a continuous stirred-tank reactor (CSTR) and in an anaerobic membrane bioreactor (AnMBR). Mesophilic CSTR operated at 50 days SRT only achieved 11.9% of anaerobic biodegradability whereas in the AnMBR at 70 days SRT and 50 days HRT reached 39.5%, which is even higher than the biodegradability achieved in the thermophilic CSTR at 50 days SRT (30.4%). Microbial analysis revealed a high abundance of cellulose-degraders in both re…

Degradación anaerobia de microalgas procedentes del tratamiento del efluente de un reactor anaerobio de membranas sumergidas

2017

La escasez de recursos naturales y el agotamiento de los combustibles fósiles han impulsado un creciente interés en el uso de microalgas, dado que han sido reconocidas como una de las alternativas más sostenibles para suplir la demanda energética global a largo plazo y detener los acusados problemas asociados al cambio climático. Actualmente, la combinación de un tratamiento anaerobio de agua residual y su post-tratamiento mediante un cultivo de microalgas supone una prometedora alternativa, pues permite la obtención simultánea de energía en forma de biogás y un recurso hídrico reutilizable, mientras que los nutrientes son empleados para la producción de una biomasa algal, susceptible de va…

Anti-ossidanti naturali per polimeri biodegradabili

2012

Biodegradability Prediction of Fragrant Molecules by Molecular Topology

2016

Biodegradability is a key property in the development of safer fragrances. In this work we present a green methodology for its preliminary assessment. The structure of various fragrant molecules is characterized by computing a large set of topological indices. Those relevant to biodegradability are selected by means of a hybrid stepwise selection method to build a linear classifier. This model is compared with a more complex artificial neural network trained with the indices previously found. After validation, the models show promise for time and cost reduction in the development of new, safer fragrances. The methodology presented could easily be adapted to many quasi-big data problems in R…

LAVORABILITA E PROPRIETA MECCANICHE DI POLIMERI BIODEGRADABILI

2012

Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae

2017

[EN] A laboratory bioreactor using rumen microorganisms to treat Scenedesmus spp. biomass was operated for 190 days. At first the bioreactor operated as a Rumen-like Fermenter (RF) with a Sludge Retention Time (SRT) of 7 days. The RF was subsequently transformed into an anaerobic digestion system including two configurations: continuously-stirred tank reactor and anaerobic membrane bioreactor in which different SRT values of up to 100 days were assessed. Methane production peaked at 214 mL CH4 g−1 CODIn with a SRT of 100 days. COD removal and BDP peaked at above 70% and 60%, respectively, at the highest SRT, with no pre-treatment prior to microalgae digestion. The waste sludge product…

Trimeprazine is enantioselectively degraded by an activated sludge in ready biodegradability test conditions

2018

[EN] A great number of available pharmaceuticals are chiral compounds. Although they are usually manufactured as racemic mixtures, they can be enantioselectively biodegraded as a result of microbial processes. In this paper, a biodegradability assay in similar conditions to those recommended in OECD tests of enantiomers of trimeprazine (a phenothiazine employed as a racemate) is carried out. Experiments were performed in batch mode using a minimal salts medium inoculated with an activated sludge (collected from a Valencian Waste Water Treatment Plant, WWTP) and supplemented with the racemate. The concentration of the enantiomers of trimeprazine were monitored by means of a chiral HPLC metho…

Innesto di catene polimeriche sulla superficie di nanotube di carbonio mediante reazione di accoppiamento radicalico

2015

La modifica di nanotubi di carbonio (CNT) attraverso innesto (grafting) di catene polimeriche sulla loro superficie è un metodo efficace per promuovere la dispersione di queste cariche a livello nanometrico in una matrice polimerica. La funzionalizzazione covalente di CNT con catene polimeriche viene generalmente ottenuta sia attraverso crescita controllata di polimeri a partire dalle pareti della nanocarica mediante metodi "grafting from" sia attraverso metodi di "grafting to" che si basano sulla reazione di condensazione tra polimeri preformati e CNT opportunamente modificati. In questo lavoro viene proposto un nuovo approccio di tipo "grafting to" per innestare catene polimeriche su CNT …

Influence of photo-oxidation on the performance and soil degradation of oxo- and biodegradable polymer-based items for agricultural applications

2021

Abstract The examination of the aging behavior of polymers, blends, composites, items, etc. under different environmental conditions is a priority issue for assessing the possible applications and establishing the lifetime. In agriculture, plastic items (mulch films, irrigation tubes, etc.) are widely used and subjected to solar UV exposure that can induce photo-oxidation on macromolecular chains. Therefore, weathering under outdoor conditions and accelerated degradation tests are performed for simulating aging processes during the lifetime of materials and select appropriate stabilizers to be used. In the last decades, oxo- and biodegradable polymers have been investigated and used in agri…