Impulse response tests in completely mixed tanks and reactors. Key assumptions and steps in mathematical developments.

Stimulus-response technique is a method to obtain the Residence Time Distribution (RTD) for the elements of a fluid passing through a vessel. Generally speaking, in reactor science unsteady-state tests may often appear preferable to steady-state since they are made up of a chain of intermediate ones; but without any theoretical necessity holding. In RTD studies, however, non-steady state tests are the only conceivable ones if conservative tracers are employed, because once a transition is over there is no way to reconstruct it and assess the hydraulic behaviour of the tank. Only a series of tests with non-conservative tracers of known disappearance rate would achieve the task, but at the pr…

Rifiuti sanitari: i “coefficienti di produzione unitaria” in due casi di studio

Entalpia dei fumi prodotti dalla combustione dei rifiuti solidi

Omero. Odissea, traduzione e riscrittura di G. Monti, illustrazioni di E. Diliberto, prefazione di S. Nicosia, Nuova Ipsa, Palermo 2010, pp. 7-8.

Di crivelli, buratti, stacci, e d'altro (Poll. VI 74, Hesych. k 58 L.)

The Syrians and the Koine: Meleager of Gadara, Philodemus of Gadara, Epigrams

BIOLOGICAL DENITRIFICATION OF GROUNDWATER: BIO-PRB COLUMN TEST PERFORMANCES EVALUATION

The occurrence of nitrates in groundwater is steadily raising concern due to possible health consequences of nitrate ingestion. Biological denitrification in BIO-PRB is the enhancement of a natural process that occurs naturally when bacteria live in an environment void of oxygen with carbon availability. Bio-PRB represent a perspective of development for PRB technique but, despite the fact that this technology has already been widely used for chlorinated solvents, data on denitrification PRBs are still scarce. This paper reports on the results of an experimental study carried out for 214 days on a bench-scale pilot column (10 cm in internal diameter and 100 cm in length with sampling ports …

Disoleatori statici per il trattamento delle acque di piccole e medie utenze

Per rimuovere gli olii dalle acque reflue di piccole e medie utenze si utilizzano molto i disoleatori prefabbricati. Le verifiche di tre disoleatori commerciali di tipo statico hanno suggerito il limite inferiore per il tempo di detenzione idraulica, e quello superiore per il carico superficiale. Le vasche bi-stadio non hanno dimostrato vantaggi sulle mono-stadio.

PRODUZIONE DI RIFIUTI A RISCHIO INFETTIVO E INDICI DI COMPLESSITÀ IN UN “CENTRO TRAPIANTI”

Questo studio analizza la produzione di rifiuti a rischio infettivo in una grande struttura ospedaliera specializzata per le attività di trapianto: Ismett (Istituto Mediterraneo per i Trapianti e Terapie ad Alta Specializzazione), che si trova a Palermo. Sono state determinate le relazioni fra la quantità e la composizione dei rifiuti, da una parte; la complessità della struttura e la natura delle cure erogate, dall’altra. In letteratura si trovano regolarmente i risultati di ricerche sulla produzione di rifiuti a rischio infettivo nei più diversi Paesi del mondo; i dati pubblicati provengono quasi esclusivamente da Ospedali Generali, anche complessi e di Alta Specializzazione. Tali dati po…

Sogno e medicina nell’Asclepieo di Pergamo

The article discusses the main aspects of the onirical therapy in Greek theurgical medicine, practised, as well known, in Asclepius' temples all over Greek territor ies. Iamata, written sources and chronicles fournish reliable testimonies of activities performed in the sacred structures, most of which concerning the reading and interpretations of dreams. A privileged witness of these practices is Aelius Aristides, in the Ieroi Logoi describing the particular link connecting his psychological and metaphorical diseases to the divine power of Asclepius, revealing his healing terrific capacitis mainly through therapeutic dreams

BIOLOGICAL STABILITY ANALYSIS OF THE OFMSW MATRIX TREATED IN A COMPOSTING PLANT

Composting, mechanical-biological treatment (MBT), biodrying and biostabilization processes of pre-selected organic fraction from municipal solid wastes (OFMSW) have recently become important in municipal solid waste management. Through these treatment processes the potential impacts of the produced wastes and the volume to treat in the landfill are strongly reduced. However, the residual organic matter contained in the treated fraction may provide negative effects when e.g. the treated OFMSW is used as compost. The biological stability degree of the treated matrix provides usefull informations for the final use of it. Indeed, knowing the degree of biological stability of the compost makes …

Appunti per una interpretazione delle Trachinie

Ci siamo davvero liberati dagli antichi? Tavola rotonda con Cornelia Isler-Kerenyi, Chrissanthi Avlami, Carles Miralles, Gian Franco Gianotti, Vittorio Citti, Salvatore Cerasuolo, Luigi Lehnus, Ivano Dionigi, coordinata da S. Nicosia.

COD and TPH analysis in slops experimental treatment plants: analytical problems.

COD AND TPH ANALYSIS IN SLOPS EXPERIMENTAL TREATMENT PLANTS: ANALYTICAL PROBLEMS. In the last years, the persistence and accumulation of xenobiotic compounds in the environment created many disposal problems of oily wastewater generated by ships, mainly in engine-rooms (bilge waters) and by cleaning of tanker (slops). The high salinity levels (up to 25.000 mgL-1) and the pollutants concentration, both limit the chances of discharge into the sewer systems and address the disposal of these wastewaters to the sea. For these reasons it is necessary to treat such wastewater efficiently before discharging [1]. As a part of a broader project concerning slops treatments, this work addresses issues …

Gettare, con l’acqua sporca (vari segni diacritici, διακριτικά), anche il bambino (lo spirito aspro, δασεία)

The author agrees with the spelling reform for Modern Greek introduced in 1984 in all respects, except as regards spiritus asper (δασεία). The fact is that the latter sign, in addition to rendering comprehensible aspiration phenomena still present in modern words (per es. πενθ-ήμερο, ὑφ-ηγητής, ἀφ-ήλιο), would be an effective guide to foreign words of Greek origin (e.g. English hypocrisy, homonymy, hygiene, German Hypokrisie, Homonymie, Hygiene, French hypocrisie, homonymie, hygiène, Spanish hipocresia, homonimia, higiene). One thus gets the impression that, so to speak, “the baby has been thrown out with the bathwater”. As a final consideration, in Italian practice relating to ancient Gree…

A LAB-SCALE MICROWAVE SYSTEM FOR EXPERIMENTS OF HIGH TEMPERATURE WASTE PYROLYSIS

The reactor designed and assembled at Università degli Studi di Palermo - presented here - was conceived to explore high unit power input, high temperature reductive processes. Its main field of use therefore is likely to be the destruction of liquid waste fed as an aerosol; or of VOCs; or of granular waste making a fluidized bed. If required, a 3 - phase system including a solid catalyst could also be set up. These waste should be free of low - melting or boiling metals. Incidentally, a literature review shows that the compounds taken as benchmark in thermal VOC destruction are trichloroethylene, benzene and toluene. At lower unit power rates this MW - based system lends itself also to rec…

Effect of chemical and biological surfactants on activated sludge of MBR system: Microscopic analysis and foam test

Abstract A bench-scale MBR unit was operated, under stressing condition, with the aim of stimulating the onset of foaming in the activated sludge. Possible synergies between synthetic surfactants in the wastewater and biological surfactants (Extra-Cellular Polymeric Substances, EPSs) were investigated by changing C/N ratio. The growth of filamentous bacteria was also discussed. The MBR unit provided satisfactory overall carbon removal overall efficiencies: in particular, synthetic surfactants were removed with efficiency higher than 90% and 95% for non-ionic and ionic surfactants, respectively. Lab investigation suggested also the importance to reduce synthetic surfactants presence entering…

Il sudato pane di Adamo (ps. Ioann. Chrys. in Psalm. 92, PG LV 615. 12-20, CPG 4548)

Drawing the Materials Balance for an MBT cycle from Routine Process Measures in a Plant located in Venice

An observation term was carried on in an MBT plant owned and run by a public Company to treat MSW left by separate collection. All observations and measurements were made without interfering with the ordinary operation rules, in order to assess the efficiency of one process cycle for a given batch of waste. Analytical data came from both a) process instruments and b) physical analysis of a batch of waste entering / exiting from a selected bio-cell. From the process mass losses (about 37% – including moisture evaporation – in that single process cycle) the theoretical amounts of water and carbon dioxide produced by biodegradation were calculated. A verification of the results was tried throu…

Modelling and bench scale investigation of inclined dense jets

Incenerimento di rifiuti ospedalieri con processo pirolitico statico: un caso di studio

ABSTRACT: The Health Care Agency 6 (ASL 6) of Regione Sicilia, Italy, owns and operates a “pyrolytic static oven” for the infectious waste produced by all health care services of the District. Operation records kept by ASL were used by the authors to establish the mass and energy balances. Among the results it was found that the plant requires primary energy as oil or gas at the rate of up to two-thirds of the energy yielded by the input waste. The energy obtained (about 1,2 thermal MW) is recovered uniquely as heat: a plain technical choice that actually exposes the operator to seasonal drops in customers’ demand. It appears worth recommending to upgrade the plant, at least fitting it with…

STERILIZZAZIONE CON MICROONDE DI RIFIUTI SANITARI: DETERMINAZIONE DIRETTA DELL’EFFICACIA DEL PROCESSO

In the sterilization of those Health Care Waste that are marked as possibly infectious, microwaves (MW) have long been proposed as an alternative means to steam. The effectiveness of the operation is assessed determining the fraction that has survived to the sterilizing agent of a known starting population of micro-organisms. Customarily, this population is introduced into the waste mass in the form of one or more sealed vials. These make up an artificial environment which is completely under control; but onto it the sterilizing agent could a priori behave with higher or lower effectiveness, compared with the loose mass which is directly exposed to it. As far as the traditional steam steril…

Comparison between two MBR pilot plants treating synthetic shipboard slops: effect of salinity increase on biological performance, biomass activity and fouling tendency

The paper reports the main results of an experimental campaign carried out on two bench scale pilot plants for the treatment of synthetic shipboard slops. In particular, two membrane bioreactors (MBRs) with submerged configuration were analyzed. One MBR pilot plant (namely, Line A) was fed with synthetic shipboard slop and was subjected to a gradual increase of salinity. Conversely, the second MBR pilot plant (namely, Line B) was fed with the same synthetic shipboard slop but without salt addition, therefore operating as a “control” unit. Organic carbon, hydrocarbons and ammonium removal, kinetic constants, extracellular polymeric substances (EPSs) production and membranes fouling rates…

Modelling the changes in time of MSW properties in a landfill.

La risorsa di Babele

Health Care Waste production: measures and estimates in “V. Cervello” Hospital, Palermo, Italy.

A monitoring work was carried out in May/June 2007 in one large hospital located in Palermo. The monitoring consisted in weighing the infectious waste containers filled in some Departments purposely chosen. As a second stage of the work a comparison was attempted between the results obtained from the waste production monitoring and the Hospital’s purchases recorded in the same time. A restricted list of purchased products out of the general one was extracted. Such list allows one to calculate approximately the mass of medical devices purchased and their composition. To these materials a reasonable change in humidity after use was attributed. It was possible in this deductive way to draw a p…

PLASTICS RECOVERY FROM MUNICIPAL WASTE: MAINSTREAMS AND BY-PRODUCTS IN A CASE STUDY IN NORTHERN ITALY.

In the case study dealt with here, the factory treatments of dry Municipal Solid Waste are aimed primarily at materials recovery; restraining energy recovery to the hardly recyclable by-products. The main input consists of the so-called multipak from MSW source-sorted collection; plus packaging waste, paper and cardboard and other similar waste from curb-side collection. The principal fractions produced by the selection plant, own and operated by the Public Company in charge of MSW management, in the Year 2012 were 27 064 tonnes of plastics, 5 066 of paper, 3 014 of tin coated steel and 4 886 tonnes of extraneous fraction to dispose of. A minor – though valuable – product was aluminium. The…

Il passato mitico dei Greci

Sogno di un nevrotico di mezza età (Elio Aristide, Discorsi sacri, V 56-67 Keil)

IL RICICLO DEI RIFIUTI: MODALITA’, VANTAGGI, SVANTAGGI

Drammaturgia antica

ACQUA POTABILE: QUALITA’ OGGETTIVA, QUALITA’ LEGALE, QUALITA’ PERCEPITA DAI CONSUMATORI

The town as a concentrated source of reclaimable water and materials. Opportunities for an engineered conservation strategy.

A fierce theoretical debate is ongoing about the human species’ existence itself being sustainable for Earth and for living world. In the meanwhile cities, which are considered to concentrate the mankind’s ecological footprints, are steadily growing and gathering huge populations worldwide. This paper assumes that margins do exist to relieve the man’s burden on Nature to some extent, and that – regardless of our general concept of the matter – these margins should be exploited. The focus of this note is on beneficial use of waste water and waste to spare new resources and to create filter areas close to towns or belts around them. A brief reference is made to some official declarations and …

Dewaterability of CAS and MBR Sludge: Effect of Biological Stability and EPS Composition

The dewaterability of sludge from two conventional activated sludge (CAS) and three membrane bioreactor (MBR)-based wastewater treatment plants is investigated prior to and after anaerobic digestion. The concentration and composition of extracellular polymeric substances (EPS) mostly affect the dewaterability of all raw sludge samples. Better sludge dewaterability is observed when the concentration of proteins, carbohydrates, uronic acids, and humic acids is below approximately 400, 250, 200, and 40 mg/L, respectively. In contrast, the specific resistance to filtration (SRF) increases in the sludge samples with a higher EPS concentration. The MBR results in a lower EPS production and a uron…

Posa e recupero di cavi sottomarini per telecomunicazioni: energia e materiali in gioco.

Undersea cables for telecommunications are put out after 20 to 25 years of service in order to be replaced by new type ones that can yield a better service. As a rule, decommissioned cables are retrieved for the part stretching from the shoreline to the line (-30 m). This operation is useful from the environmental standpoint, as at the price of an energy expenditure of about 3 MJ/m an amount of materials having embodied energy as high as 72 times of it are recovered. Still, the larger part of an undersea cable lies offshore and is usually left on the site, so the actual energy recovery is small – just about few units per cent – compared with the energy (embodied + used for laying) required …

Experimental Sorting of Municipal-Like Waste in the Hospital “Civico”, Palermo (IT)

An experiment of source sorting - based management of Health Care Waste (HCW) was carried out in 2011 in 4 Departments of the Public Hospital “Civico” (Palermo, IT), where the basic mandatory separation between hazardous and non-hazardous waste was already going on since year 2000.The experiment consisted in weighing every day for 15 days 4 predefined fractions collected in the Infirmaries (namely paper, plastics, glass and unsorted fraction), and the bags with unsorted waste from the patient’s stay room. Furthermore, in 1 of the 4 Departments also the boxes of Infectious Waste (IW) were weighed for a week.As a result a weighted average value of 0.56 kg of Municipal-like Waste (MLW) per bed…

Tradurre il teatro: le Trachinie a Siracusa (2007)

Relazione al 1° Seminario sui Processi a Membrana fra Département STE del Polytech' Montpellier (F) e Dipartimento Ingegneria Idraulica e Ambientale dell'Università di Palermo (I): EXPÉRIMENTATION SUR LA CROISSANCE DE LA BIOMASSE DANS UNE INSTALLATION PILOTE À MEMBRANES

“E’ morto al posto mio”: da Elias Canetti ad Elio Aristide

Materie plastiche nei rifiuti. I fabbisogni di energia e di acqua per il recupero: un caso di studio

Submarine outfalls in Sicily: a survey

Influence of the Height of Municipal Solid Waste Landfill on the Formation of Perched Leachate Zones

Waste settlement as well as consolidation phenomena, which occur inside a landfill for municipal solid waste (MSW), can cause a decrease in waste permeability. This can lead to a reduction in conveyance of the leachate drainage system. It is therefore possible that a so-called perched leachate zone will form. Such a zone is constituted by an area in the body of the landfill where the leachate is temporarily trapped and is unable to infiltrate downward. This phenomenon is influenced by many factors, which include rain infiltration rate, waste moisture and composition, landfill height, and so on. The main aim of the paper is to elucidate the role played by landfill height in the formation of …

Hesych. l 1008 Latte likmazein: periecein

Bench-scale investigation of inclined dense jets

In this work experimental data on the geometry of dense inclined jets issuing in a lab-scale glass rectangular tank are presented. The surrounding fluid was always tap water at room temperature while the dense jets were water solutions of NaCl. Four parameters were changed in the experiments, namely nozzle diameter and inclination, and jet density and flow rate. Jet trajectories were revealed by a colored tracer. Images of the jet were recorded by a digital camera and then further digitally processed, eventually resulting in a time-averaged tracer intensity field. All the jet geometrical parameters, once normalized, were found to be very well correlated to the densimetric Froude number. Mod…

Biogas from municipal solid waste landfills: A simplified mathematical model

AbstractMunicipal solid waste (MSW) landfills now represent one of the most important issues related to the waste management cycle. Knowledge of biogas production is a key aspect for the proper exploitation of this energy source, even in the post-closure period. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on first-order biodegradation kinetics and also takes into account the temperature variation in time and depth as well as landfill settlement. The model was applied to an operating landfill located in Sicily, in Italy, and the first results obtained are promising. Indeed, the results showed a good fit between me…

Physical features of Health Care Waste

A monitoring work was recently carried out in two major Health Care Facilities (HCFs) in Italy, both located in Palermo, to obtain information on waste generation rates. Monitoring consisted in weighing infectious waste containers for 15 days in 4 Departments for each health care facility. From values obtained monthly production, specific weights and Production Indexes were calculated. The main producers of waste appeared Oncological DH and Resuscitation for both HCFs, with more than 4 and 3 kg measured per occupied place and day, respectively. About specific weight, apparent bulk values always below 200 kg/m3 were calculated. From the short observation performed it seems that notable impro…

Problemi del trattamento combinato di reflui urbani e rifiuti liquidi

Multivariate analysis of historical data (2004-2013) in assessing the possible environmental impact of the Bellolampo landfill (Palermo).

Multivariate analysis was performed on a large data set of groundwater and leachate samples collected during 9 years of operation of the Bellolampo municipal solid waste landfill (located above Palermo, Italy). The aim was to obtain the most likely correlations among the data. The analysis results are presented. Groundwater samples were collected in the period 2004–2013, whereas the leachate analysis refers to the period 2006–2013. For groundwater, statistical data evaluation revealed notable differences among the samples taken from the numerous wells located around the landfill. Characteristic parameters revealed by principal component analysis (PCA) were more deeply investigated, and corr…

Monitoring activity to assess the quality conditions of a river: the case study of Oreto, Italy

MODELLING BIOGAS GENERATION AND RELEASE FROM MUNICIPAL SOLID WASTE LANDFILLS

MSW sanitary landfills represent nowadays one of the most important issue related to the waste management cycle. In particular, knowledge about biogas production is a key aspect for a proper exploitation of this energy source, even in the after-care phase. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on 1st order biodegradation kinetic and takes also into account the temperature variation in time and depth and the landfill settlement. The model was applied to a real landfill located in Sicily (ITALY) and its simulation result was compared with experimental data (volumes of biogas collected by the recovery system a…

Le Trachinie dell’intellettuale Pagliaro, “Dioniso” 6, 2008, pp. 316-321

Vietato piangere. La repressione del lutto nella Grecia antica e nella Sicilia moderna

Altre vie per l'immortalità nella cultura greca

Revival cristologico e Vangeli

Indagine sulla produzione dei rifiuti sanitari nella Provincia di Palermo

UNIVERSITA’ DEGLI STUDI DI PALERMO - LABORATORY OF SANITARY ENGINEERING

Interpreting and modelling field data for wastewater dispersion into sea trough dimensional analysis

This paper deals with the mathematical and experimental characterization of a coastal urban wastewater discharge in the South Tyrrhenian Sea, namely the Golfo di Palermo, western Sicily (Italy). The stretch of water lying before the central part of the capital town receives the wastewater originating from about 200 000 inhabitants. The sewage is currently still discharged on-shore without any prior treatment by a free-surface outfall called “Porta Felice”. The Municipality is currently implementing a plan to connect the sewerage system of these areas to the main wastewater treatment plant; at the moment, however, no mitigation measure has been applied yet and the quality of the Gulf is stil…

Health Care Waste production: measures and estimates in Joint Hospitals “Civico e Benfratelli, Ascoli e Di Cristina”, Palermo, Italy.

A monitoring work was carried out in October 2006 in one large health care facility located in Palermo. The monitoring consisted in weighing infectious waste containers filled in some Departments purposely chosen. As a second stage of the work a comparison was attempted between the results obtained from the waste production monitoring and the archive data recorded in the same time. A restricted list of purchased products out of the general one was extracted. Such list allows one to calculate approximately the mass of medical devices purchased and their composition. To these materials a reasonable change in humidity after use was attributed. It was possible in this deductive way to draw a pr…

Physical dispersion and disappearance of bacteria in the Golfo di Palermo: the results of two surveys.

This paper reports on some results of two surveys at sea carried out in the surroundings of a urban wastewater discharge on the coast of the Golfo di Palermo, western Sicily (Italy). At the time of the surveys (year 2005) the stretch of water lying before the central part of the capital town received the untreated wastewater originating from about 200 000 inhabitants, which was discharged on-shore without any prior treatment by the free-surface outfall of “Porta Felice main sewer”. This outfall has crucial importance in the water quality; indeed, the Municipality is steadily implementing a plan featuring an intercepting main sewer along the coast and some pumping stations to connect all the…

Aristofane, Lisistrata, traduzione teatrale

Trachinie di Sofocle, traduzione di Salvatore Nicosia, XLIII Ciclo di spettacoli classici, Siracusa 2007