Search results for "IFAS"

Hybrid moving bed biofilm reactors: an effective solution for upgrading a large wastewater treatment plant

2009

Over the last few years there has been a growing attention regarding the receiving water body quality state. As a matter of a fact, the Directive 91/271 of the European Union (EU) replaced the “emission standard” concept that fixes discharge limits depending on polluting emission characteristics, with the “stream standard” concept that fixes discharge limits for each polluting substance depending on self-depurative characteristics of the RWB. In this context, several WWTPs need to be upgraded in order to meet stricter effluent limits. The need of WWTP upgrading was also emphasized by the growing urbanization that have led, in most cases, to get overloaded WWTP due to an overcoming of the ma…

Nitrous oxide from integrated fixed-film activated sludge membrane bioreactor: Assessing the influence of operational variables

2017

The influence of the main operational variables on N2O emissions from an Integrated Fixed Film Activated Sludge University of Cape Town membrane Bioreactor pilot plant was studied. Nine operational cycles (total duration: 340 days) were investigated by varying the value of the mixed liquor sludge retention time (SRT) (Cycles 1–3), the feeding ratio between carbon and nitrogen (C/N) (Cycles 4–6) and simultaneously the hydraulic retention time (HRT) and the SRT (Cycles 7–9). Results show a huge variability of the N2O concentration in liquid and off-gas samples (ranged from 10−1μg N2O-N L−1to 103μg N2O-N L−1). The maximum N2O concentration (1228 μg N2O-N L−1) in the off-gas sa…

Nitrous oxide from moving bed based integrated fixed film activated sludge membrane bioreactors

2017

Abstract The present paper reports the results of a nitrous oxide (N 2 O) production investigation in a moving bed based integrated fixed film activated sludge (IFAS) membrane bioreactor (MBR) pilot plant designed in accordance with the University of Cape Town layout for biological phosphorous removal. Gaseous and liquid samples were collected in order to measure the gaseous as well as the dissolved concentration of N 2 O. 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 N 2 O was, however, also found in the anaerobic …

Moving bed membrane bioreactors for carbon and nutrient removal: The effect of C/N variation

2017

In this paper, an experimental campaign was carried out on a University of Cape Town Integrated Fixed Film Activated Sludge Membrane Bioreactor (UCT-IFAS-MBR) pilot plant. The aim of the study was to evaluate the effect of the influent C/N ratio on the system performance in terms of organic carbon, nitrogen and phosphorus removal, biomass viability (through respirometry), activated sludge features and membrane filtration properties. The experiments were organized into three phases, characterized by a variation of the C/N ratio (namely, Phase I: C/N= 5, Phase II: C/N =10; Phase III: C/N = 2). The results highlighted that the system performance was significantly affected by C/N ratio. The rem…

The influence of solid retention time on IFAS-MBR systems: Assessment of nitrous oxide emission

2017

The aim of the present study was to investigate the nitrous oxide (N2O) emissions from a moving bed based Integrated Fixed Film Activated Sludge (IFAS) - membrane bioreactor (MBR) pilot plant, designed according to the University of Cape Town (UCT) layout. The experimental campaign had a duration of 110 days and was characterized by three different sludge retention time (SRT) values (∞, 30 d and 15 d). Results highlighted that N2O concentrations decreased when the biofilm concentrations increased within the aerobic reactor. Results have shown an increase of N2O with the decrease of SRT. Specifically, an increase of N2O-N emission factor occurred with the decrease of the SRT (0.13%, 0.21% …

La "Res Publica" (1931-1933) di Francesco Luigi Ferrari - contributi storici e politico-dottrinali

2009

Il 12 aprile 1930, dal suo esilio londinese, Luigi Sturzo scriveva al giovane popolare Francesco Luigi Ferrari chiedendo un preventivo per una rivista e i nomi degli eventuali collaboratori. Prendeva, così, l’avvio l’iniziativa editoriale del bimensile «Res Publica», Revue d’études politiques internationales, redatta in lingua francese, destinata a durare solo diciassette mesi, ma capace di lasciare una grande lezione di cultura democratica popolare, di dare voce a intellettuali di diverse esperienze e formazioni, accomunati tutti dall’opposizione al fascismo, dalla condanna ai regimi totalitari distruttori della libertà. «Res Publica» rappresentò lo strumento internazionale per condurre il…

Fascismo, antifascismo, spirito del tempo. A proposito di un dibattito in corso

2019

Il dibattito sul fascismo e l'anti-ascismo nell'Italia repubblicana

La nación contra el fascismo: PSOE y SFIO, 1933-1936

2020

Este artículo propone un estudio del antifascismo socialista en España. Al respecto, se apuesta por situar la nación como referente cultural y político en el centro del análisis, y aplicar una perspectiva comparada con el caso de Francia. Dicho análisis se plantea para el período inmediatamente anterior a la Guerra Civil en España y toma como principal fuente a la prensa socialista.El artículo se desarrolla en dos grandes bloques, con la Revolución de Octubre de 1934 como hito. A partir de entonces emergió en el seno del PSOE un enfrentamiento por el control de la organización. El artículo se centra en el estudio de la corriente caballerista, considerada el ala izquierdista, a la cual se co…

La sombra del fascismo

1998

La redazione del Domani d’Italia 1922-1924 : valori cristiani e difesa delle libertà democratiche

2023

Noto periodico edito a Milano dal 24 dicembre 1922 al 9 luglio 1924 e ispirato dal popolarismo, il «Domani d’ItaLia» nacque come una «piccola fiaccola» che avrebbe dovuto illuminare in quel momento di “buio” «fino all’alba del domani». Grazie allo sforzo congiunto, la redazione organizzò una resistenza “armata” solo di inchiostro per denunciare le conseguenze che il 28 ottobre 1922 avrebbe determinato nella storia italiana ed europea e per contribuire a creare una coscienza democratica ritenuta necessaria nella formazione della generazione che sarebbe stata chiamata a rinnovare le istituzioni politiche dopo la fine del fascismo. Attraverso il dibattito condotto dai redattori nelle pagine de…