1,720,963 research outputs found
Treatment of distillery wastewater by a pilot scale anaerobic sequencing bacth reactor
No full textIl comparto della distillazione in Italia rappresenta un’importante realtà economica ed industriale data l’enorme disponibilità di sottoprodotti da trasformare in alcool, provenienti in particolare dal settore vitivinicolo. Le distillerie, qualunque siano le materie prime utilizzate, danno luogo a notevoli quantitativi di reflui inquinanti, ad alta concentrazione di sostanza organica, che necessitano di un trattamento di depurazione a monte dello scarico nei corpi idrici recettori.
La digestione anaerobica dei reflui di distilleria è ampiamente applicata in scala reale come sistema di depurazione poiché consente di ottenere una notevole riduzione della sostanza organica con la produzione di biogas (ad elevato contenuto di metano) utilizzabile come fonte di energia.
Attualmente, la ricerca scientifica nel campo della digestione anaerobica dei reflui di distilleria è orientata allo sviluppo di sistemi di depurazione caratterizzati da bassi tempi di ritenzione idraulica ed elevate età del fango. Tra questi sistemi, particolare interesse riveste l’ASBR (Anaerobic Sequencing Batch Reactor), nel quale il processo depurativo è articolato in una successione di cicli caratterizzati dalle seguenti fasi: carico dell’influente, reazione in ambiente anerobico e scarico dell’effluente. Il principale vantaggio dell’ASBR, rispetto ai sistemi tradizionali, consiste in un maggior controllo e flessibilità dell’intero processo biologico.
La Sezione Gestione Risorse Idriche dell’ENEA di Bologna ha curato la progettazione e realizzazione di un impianto ASBR in scala pilota (180 l) allo scopo di verificare l’efficienza di depurazione su reflui di distilleria con caratteristiche fisico-chimiche differenti fra loro.
Sono stati testati 4 tipologie di reflui (borlanda, due reflui misti e melasso) alimentati in modo da operare con un fattore di carico organico volumetrico pari a circa 5 kg COD/(m3 giorno).
L’efficienza di rimozione della sostanza organica (in termini di COD) è stata superiore al 70% (e nel caso della borlanda oltre il 90%).
La produzione di biogas è risultata variabile con la tipologia di refluo, presentando un fattore di produzione compreso tra 1 e 3 litri di biogas /litro di reattore.
Complessivamente si è avuta una produzione di gas metano pari a 340 l/(kg COD rimosso) valore prossimo a quello teorico di 350.
A differenza dei tradizionali sistemi CSTR, gli ASBR non necessitano, tra l’altro, di una fase di sedimentazione, rappresentando quindi una valida alternativa per il trattamento anaerobico dei reflui di distilleria
Analysis of an archaeological linen cloth: The shroud of Arquata
No full textThe linen cloth of the shroud of Arquata, a precious copy of the Shroud of Turin which dates back to 1653, was discovered in 1980 during the restoration works of the St. Francis church in Arquata del Tronto (Ascoli Piceno, Italy). Following the strong earthquake that hit central Italy in August 2016, the church was seriously damaged and it was therefore necessary to secure the shroud in the Cathedral of Ascoli Piceno. A multidisciplinary approach was required in order to evaluate the correct intervention methods that will be performed in the next future: although several investigation techniques were performed on the Arquata shroud, this paper focuses on the combination of two different techniques, optical microscopy and scanning electron microscopy coupled with energy dispersive spectroscopy microanalysis (SEM-EDS). Few samples of fibrils of the linen cloth of the Arquata shroud were analysed, achieving information about their morphology, the surface characteristics, the chemical composition and the possible deterioration phenomena. Light microscopic analyses showed some typical features of the single elementary flax fibre: lumen, dislocations and cross markings (X). SEM-EDS analysis also revealed interesting morphological features of the flax fibrils and the presence of encrustations on their surface, while the microanalysis preformed on the encrustations revealed the presence of calcium, silicon, magnesium, aluminium, sodium, and potassium, due to dust deposits. Moreover, the absence of biological attacks by microorganisms, parasites, moulds or fungi was highlighted. Finally, numerous defects of the surface that could characterise the linen cloth as antique were identified (cross cuts). These results suggested some actions useful for the conservation of the shroud, thus avoiding the use of more invasive methods which could impact the integrity of this precious object of veneration
Evaluation of the controlled hydrodynamic cavitation as gas mass transfer system for ex-situ biological hydrogen methanation
No full textThe present work represents the first study focused on controlled hydrodynamic cavitation applied as gas transfer system to supply the methanogenic archaea with exogenous H2 and CO2. Starting from a generic mixed inoculum sampled from a thermophilic full-scale anaerobic digester, a bubble column bioreactor was coupled with a rotating hydrodynamic cavitator and fed with different H2/CO2 loading rates. Process efficiency and long-term effects on process stability and microbial population were evaluated. Gas sparging through the controlled hydrodynamic cavitation device is feasible under the operating conditions tested, resulting in almost 100% efficiency in H2 utilization and recording a CH4 volumetric content more than 99% in the gas leaving the reactor, without any gas recirculation from the headspace. The experimental trials lasted about 160 days and the behavior of the bioreactor showed a substantial stability over the time. Metagenomic and FISH analyses were carried out at the end of the experimental trials, revealing a remarkable increase of hydrogenotrophic methanogens species, related to the selection-effect of H2 on community composition. The findings provide previously unidentified insights into long-term effect on process stability and microbial community diversity in the biological hydrogenotrophic methanation process coupled with a gas–liquid mass transfer system based on controlled hydrodynamic cavitation technology
Feasibility of Heavy Metal Polluted Lagoon Sediment Phytoremediation: a Pilot-Scale Application
No full textReuse of treated municipal wastewater in agriculture in MENA countries: the Lebanese case study
No full textThe Middle East and North Africa (MENA) is the most arid region on Earth. Due to water scarcity, combined with over population, inefficient water use especially in the agricultural sector, climate change, and mass migration of humans from to various regional conflicts, recycling wastewater has become a necessity for many. Furthermore, with this growing population comes the increase in food demand; the region does not have the natural water resources to withstand this phenomenon and needs be proactive in its environmental and agricultural policy. This paper describes the activities carried out in Lebanon by the ENEA Agency in order to set some conditions for the safe reuse of treated wastewater in agriculture such as (i) identification of the most suitable guidelines for agriculture wastewater reuse and (ii) assessment of the performance capacity of municipal wastewater treatment plants (WWTPs) so as to achieve the discharge limit values (LVs) previously identified. With reference to the first point, several international guidelines, WHO, FAO, US approach, as well as those for Mediterranean countries, were addressed. With reference to the second one, WWTPs located in the Bekaa valley, inner part of Lebanon with agricultural vocation, were considered. After the identification of each plant, a simple methodology to assess the WWTP capacity to achieve targets imposed by the FAO proposal guideline (2010) was implemented. The obtained results showed how, at first, it is necessary to adapt the Lebanese WWTPs in order to ensure the targets imposed by Lebanese Law for the discharge of the treated wastewater in surface and sea waters and then, adapt the plants in order to ensure the standards by WHO 2006. Finally, based on the energy availability, evaluate the possibility to adopt other approach using more sophisticated wastewater reuse technologies (from WHO to US approach)
Growth of Silver Nanoparticles Embedded in a Polyacrylamide—Alginate Hybrid Hydrogel
No full textHydrogels represent a versatile class of materials with remarkable potential as
three-dimensional matrices for nanoparticle integration. This study explores the mechanism of silver nanoparticle formation within a polyacrylamide–alginate hybrid hydrogel,
employing a controlled reduction–oxidation reaction between silver nitrate (AgNO3) and
sodium borohydride (NaBH4) across a temperature gradient (5–70 ◦C). Characterization
techniques, including Raman, infrared, and UV-Vis spectroscopies, X-ray diffraction, and
scanning electron microscopy, were employed to analyze the structural and optical properties of the nanoparticles and the hydrogel. The results show that, as the temperature rose,
nanoparticle numbers decreased, while their size increased. Consistently octahedral in
shape and averaging 100–120 nm, these nanoparticles revealed a temperature-dependent
growth pattern, with rare larger crystals emerging more frequently at higher temperatures. The findings highlight the potential of hybrid hydrogels as effective matrices for
the incorporation of metal nanoparticles, paving the way for applications in drug delivery,
biosensing, and antimicrobial treatments
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
