Search results for " ingegneria"
showing 10 items of 796 documents
Start-up of a submerged membrane bioreactor with complete sludge retention
2005
The sludge dewaterability in membrane bioreactors
2016
The influence of the sludge origin on the dewaterability features has been investigated by comparing the experimental results of six membrane bioreactor pilot plants with different configurations. The capillary suction time (CST) and the specific resistance to filtration (SRF), identified as representative of sludge dewaterability features, were measured. The results were related to operational parameters, such as extracellular polymeric substances (EPS) and soluble microbial product (SMP), influent salinity and hydrocarbon, in order to elucidate the influence exerted on the dewaterability. Furthermore, the effect of biofilm and suspended biomass was also investigated. The results showed th…
Greenhouse gas from moving bed based integrated fixed film activated sludge membrane bioreactors
2016
The present paper reports the results of a nitrous oxide production investigation in a moving bed based integrated fixed film activated sludge (IFAS) membrane bioreactor (MBR) pilot plant designed in accordance with the UCT layout for biological phosphorous removal. Samples of gas and liquid were collected in order to measure the gaseous, as well as the dissolved concentration of N2O. Furthermore, the gas flow rate from each reactor was measured and the gas flux was estimated. The results confirmed that the anoxic reactor represents the main source of nitrous oxide production. A significant production of N2O was, however, also found in the anaerobic reactor, thus indicating a probable occur…
Il progetto degli impianti MBR: configurazione dei reattori, componenti e particolari costruttivi.
2016
Vengono discussi alcuni aspetti della progettazione degli impianti MBR, come la scelta della configurazione, la scelta delle membrane, delle dotazioni elettromeccaniche e delle opere accessorie degli impianti MBR. Inoltre sono riportati dei cenni sulle soluzioni tecnologiche più innovative atte a minimizzare le disfunzioni dei sistemi MBR e di conseguenza dei costi operativi. La scelta di sistemi con flusso a pistone in impianti MBR ha impatti negativi sia sulla per quanto concerne il fenomeno del foaming che quello del fouling. Per la scelta delle membrane risulta che quelle piane siano utilizzate sia per applicazioni industriali che civili, quasi esclusivamente in impianti a configurazion…
La corretta progettazione e gestione degli impianti, come garanzia di protezione per l’ambiente
2019
rappresentano requisiti essenziali per la protezione dell’ambiente. In particolare, la conoscenza dei fenomeni che si instaurano al loro interno, perlopiù di natura biologica, è di fondamentale importanza per la buona riuscita del processo depurativo, sia che si tratti di impianti a tecnologia convenzionale, quali i CAS (Conventional Activated Sludge), o avanzate, quali gli MBR (Membrane BioReactor). Il verificarsi di una disfunzione, a seconda della sua gravità, può comportare il superamento dei limiti previsti per lo scarico per un certo periodo di tempo, causando gravi conseguenze ambientali, nonché un danno economico che deriverebbe sia dall’applicazione di sanzioni amministrative, cons…
BioMAc 2013. I bioreattori a membrana per la depurazione delle acque reflue
2013
Foaming in membrane bioreactor: identification of the causes
2012
The biological foaming was related to the metabolism of certain microorganisms that synthesize and excrete hydrophobic compounds. Recently, by the attention of many researchers the biological foaming in the MBR has attracted, because MBR foam has been also observed in the absence of foam-forming microorganisms, contrarily to conventional activated sludge systems. In this paper the authors investigate the role of EPS and filamentous bacteria analyzing different samples from different MBR pilot plants. In particular, in order to define the macroscopic features and the role of EPS and filamentous bacteria a modified Scum Index (MSI) test was applied. Further a multiple classification of SI was…
Criteri di progettazione dei bioreattori a membrana
2013
Evaluation of biomass activity in membrane bioreactors by means of respirometric techniques
2016
The paper reports the main results of a respirometric experimental survey carried out on several membrane bioreactor pilot plants, characterized by different pilot plant layouts as well as operational conditions. The main aim was to assess the influence of specific conditions on biokinetic/stoichiometric parameters. In particular, the respirometric tests were specifically aimed at investigating the activity of both heterotrophic and autotrophic bacterial species. The achieved results showed that the plant configuration and the features of the feeding wastewater and operational conditions determine significant variation of the kinetic coefficients. The respirometric analysis was confirmed to…