Comparison between MBR and MB-MBR pilot plants subject to a gradual salinity increase: analysis of biokinetic and fouling behaviour

Two pilot plants were investigated for the treatment of wastewater subject to a gradual increase of salinity. In particular, a membrane bioreactor (MBR) and a moving bed biofilm membrane bioreactor (MB-MBR) were studied. Carbon and ammonium removal, kinetic constants and membranes fouling rates have been assessed. Both plants showed very high efficiency in terms of carbon and ammonium removal and the gradual salinity increase led to a good acclimation of the biomass, as confirmed by the respirometric tests. Significant biofilm detachments from carriers were experienced, which contributed to increase the irreversible superficial cake deposition. However, this aspect prevented the pore foulin…

Analysis of Biomass Characteristics in MBR and MB-MBR Systems Fed with Synthetic Wastewater: Influence of a Gradual Salinity Increase

The paper presents the results of a field gathering campaign carried out on two different pilot scale membrane bioreactor (MBR) systems, treating synthetic wastewater subject to a gradual increase of salinity. One was a conventional MBR system, while the other was a moving bed biofilm membrane bioreactor (MB-MBR), which combines suspended biomass and biofilm. Indeed, the presence of suspended carriers inside the bioreactor seems to give benefits due to the collisions between the circulating media and the membrane. The aim of the study was the comparison of two configurations in terms of biomass activity characterization and performance (pollutants removal and hydraulic behaviour). The resul…

Natural Fiber-Reinforced Composites

Over the last decade, composites of polymers reinforced with natural fibres have received increasing attention, both from the academic world and from several industries. There is a wide range of natural fibres which can be applied as reinforcements or fillers thanks to their properties and availability; i.e. flax, hemp, jute, kenaf and sisal. Natural fibres are mainly attractive for the following reasons: specific properties, price, health advantages and recyclability. Particularly, industry is getting more and more interested in environment-friendly products and therefore the research on natural fibre based on composite materials is gaining importance. Some of the benefits linked to the us…

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 …

The role of EPS in fouling and foaming phenomena occurring in an UCT-MBR pilot plant

The aim of this study is to detect a possible relationship between EPS and fouling and EPS and foaming in a University Cape Town (UCT) membrane bioreactor (MBR) pilot plant. The UCT-MBR pilot plant was fed with 40 L/h of real wastewater and monitored for 165 days. Specifically physical/chemical features of influent, permeate and mixed liquor in different sections were analyzed. The fouling phenomenon was studied monitoring the hydraulic resistances of the membrane. The extracellular polymeric substances (EPSs) concentration inside the aerobic tank were also measured. The foaming phenomenon was monitored by performing the Foam Power and Scum Index testes. Results have shown a high correlatio…

OSSERVATORIO SUGLI IMPIANTI DI DEPURAZIONE MBR - Rapporto 2016

I reattori biologici a membrana (MBR, dall’inglese Membrane Biological Reactor) derivano dall’accoppiamento dei tradizionali processi a biomassa sospesa con i processi di filtrazione su membrane microporose o ultraporose, a seconda delle dimensioni nominali dei pori. I maggiori vantaggi legati a questa tecnologia vanno ricercati nella possibilità di eliminare, a valle della fase biologica, quella dei vincoli gestionali ed operativi a quest’ultima connessi. La sostituzione della sedimentazione con una fase di filtrazione su membrane comporta: una notevole riduzione dell’ingombro planimetrico dell’impianto di depurazione, dovuta sia alla eliminazione delle unità di sedimentazione che alla d…

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 …

L’IPOTIROIDISMO NELLE PERSONE ANZIANE: IMPORTANZA DI UNA ADEGUATA TERAPIA SOSTITUTIVA ORMONALE

La prevalenza dei disturbi della ghiandola tiroidea aumenta con l’età, soprattutto nelle donne. L’ipofunzione tiroidea conclamata in età avanzata può manifestarsi clinicamente con sintomi e segni simili alle modificazioni che normalmente accompagnano l’invecchiamento o come disturbi di altri organi. Per tale motivo, un alto indice di sospetto è essenziale per rilevare l’ipotiroidismo in anziani con comorbilità multiple, alterazioni nutrizionali e/o polifarmacoterapia. La decisione di iniziare una terapia sostitutiva ormonale nell’ipotiroidismo conclamato non è discutibile. Viceversa, esiste ancora controversia sulla decisione di trattare o non trattare l’ipotiroidismo subclinico; le raccoma…

Biological nutrient removal in a UCT-MBR pilot

In the last years, there has been an increasing awareness about the environment pollution protection. As a consequence, the Environmental Regulation has increased the emission limits imposing, for instance, lower concentrations at the wastewater treatment plant (WWTP) outlets. As a consequence of this fact, several WWTPs are not able to respect the emission limits and need to be upgraded. In view of such needs new technology are emerging and new WWTP solution schemes are being realized. With respects to the nutrient removal enhancing, a possible solution can be the UCT-MBR which couples the University of Cape Town scheme with a Membrane Bioreactor. In the light of such considerations, the s…

Analisi sperimentale e modellistica di formazione del fouling delle membrane nei sistemi MBR

Biological nutrient removal using intermittent aeration in a hybrid moving bed biofilm reactor

The paper presents an experimental study on a lab scale pilot plant in a Hybrid Moving Bed Biofilm Reactor. The pilot plant was fed with synthetic wastewater and was in operation considering two different operating conditions: continuous aeration and intermittent aeration. Both continuous and intermittent aeration were monitored and compared in order to seek the best conditions for carbon and nitrogen removal. At the beginning of the experimentation, an initial period of about 90 days was considered during which the pilot plant worked in bench scale configuration for allowing the formation of biofilm on the carriers. Once the biofilm growth was accomplished, the pilot plant worked for a fir…

The SND process in two granular sequencing batch reactors with different mean granule sizes: a case study.

Newspaper-reinforced biomimetic cellular biocomposites for automotive applications: experimental and numerical

Proposte metodologiche per la valutazione del potenziale di geoscambio: il Progetto VIGOR

In the framework of VIGOR Project, a national project coordinated by the Institute of Geosciences and Earth Resources (CNR-IGG) and sponsored by the Ministry of Economic Development (MiSE), dedicated to the evaluation of geothermal potential in the regions of the Convergence Objective in Italy (Puglia, Calabria, Campania and Sicily), is expected to evaluate the ability of the territory to heat exchange with the ground for air conditioning of buildings. To identify the conditions for the development of low enthalpy geothermal systems collected and organized on a regional scale geological and stratigraphic data useful for the preparation of a specific thematic mapping, able to represent in a …

Caratterizzazione di compositi a matrice epossidica rinforzati con fibre di vetro e di opuntia-ficus indica

Effect of sheep wool fibres on thermal-insulation and mechanical properties of cement matrix

The use of sheep wool as reinforcement of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, in several regions it is treated as a waste and, consequently, its employ is characterized by low cost. Aim of this paper is to evaluate the influence of wool fibres on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibres, obtained from a breed of Sicilian sheep, with three different length (i.e. 1 mm, 6 mm and 20 mm). Moreover, in order to evaluate the influence of fibre content, the samples were prepared by varying the fibres weight fraction up to maximum level. The thermal conductivity of …

TERAPIA ACUTA DEL DOLORE E CAPACITÀ FUNZIONALE IN PAZIENTI AMBULATORIALI

A new failure modes predictive tool in composite laminate mechanical joint

Use of oral anticoagulant drugs in older patients with atrial fibrillation in internal medicine wards

no abstract available

Foaming in membrane bioreactor: identification of the causes

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…

RIMOZIONE COMBINATA DI CARBONIO E NUTRIENTI IN DUE REATTORI SBR GRANULARI: EFFETTO DELLA DIMENSIONE DEI GRANULI

Sono state investigate le performance di due impianti SBR (Sequencing Batch Reactor), alimentati con refluo sintetico a base di acetato di sodio e funzionanti con due differenti tipi di fango aerobico granulare, in termini di dimensione media dei granuli. In particolare, è stato analizzato l’impatto della differente dimensione dei granuli sul processo di nitrificazione e denitrificazione simultanea (Simultaneous Nitrification Denitrification, SND) e sulla rimozione biologica del fosforo. Allo scopo di valutare l’efficienza di tale tipo di processo, sono state applicate differenti strategie di coltivazione e condizioni operative, in termini di carico organico (COD 600-1200 mg/L) e azoto (60-…

Performance of a MBR pilot plant treating high strenght wastewater: analysis of biomass activity and fouling behaviour

Nowadays, due to the increasing awareness about environmental impact of discharges, it is necessary to realize biological processes that allow complete treatment of wastewater, able to produce high quality effluents that could be used for recycling and reuse purpose. A possible solution to cope with this issue is represented by membrane bioreactors (MBRs), which are combined systems including a bioreactor and a filtration unit. However, in presence of high strenght domestic or industrial wastewater, a modification in biomass kinetics as well as in sludge characteristics may occur. This situation is of importance, since microbial community characteristics can play an important role in membra…

Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

Objectives Few studies have analyzed factors associated with delirium subtypes. In this study, we investigate factors associated with subtypes of delirium only in patients with dementia to provide insights on the possible prevention and treatments. Design This is a cross-sectional study nested in the "Delirium Day" study, a nationwide Italian point-prevalence study. Setting and participants Older patients admitted to 205 acute and 92 rehabilitation hospital wards. Measures Delirium was evaluated with the 4-AT and the motor subtypes with the Delirium Motor Subtype Scale. Dementia was defined by the presence of a documented diagnosis in the medical records and/or prescription of acetylcholine…

FRATTURE OSTEOPOROTICHE IN PAZIENTI CON DEMENZA

The Influence of MSW Landfill Height in the Perched Leachate Formation

During the last decades, the largest part of municipal solid waste (MSW) generated world wide has been disposed of in landfills without any pre-treatment. The main environmental impacts of such landfills, containing high amounts of biodegradable organic matter, are caused by emissions of liq-uid effluents and landfill gas. With no collection and treatment, leachates from landfills pollute groundwater and soils locally. Furthermore, besides the biological processes, many physical phe-nomena occur inside the landfill body which negatively affect landfill management. Indeed, the waste settlement inside the landfill body, with a consequent increase of its density, corresponds to a proportional …

Direct Measurement of Methane Emission Rates: Multiyear Application to a Municipal Landfill in Southern Italy

Municipal Solid Waste (MSW) landfills have been identified as one of the most important sources of methane (CH4) emission. MSW contains a certain amount of biodegradable organic matter which undergoes anaerobic degradation resulting in the production of the landfill gas (LFG), which main component is tipically represented by CH4. In order to minimise its negative effects on the envi-ronment, LFG recovery is a suitable tool to control CH4 emissions from a landfill site and the measurement of CH4 emissions represents a good way to evaluate the effectiveness of LFG recover-ing system in reducing biogas emission to the atmosphere. However, up to now few measurements of landfill CH4 emissions ha…

Comparison of a MBR system start-up with and without inoculum: experimental and mathematical model application

The performance of a membrane bioreactor (MBR) system and the extension and mechanisms that lead to the formation of the fouling may differ in relation to the start-up. As a consequence, the MBR start-up may constitute a crucial point that drastically influence the MBR performance in its lifespan. Indeed, the start-up influences the mechanisms of membrane fouling whose effects, in the case of irreversible cake deposition, can be modified only by a chemical membrane washing. In order to gain insights about the effect of the start-up on a MBR system, a MBR pilot plant was build-up and a mathematical model developed. The MBR system was constituted by a hollow fibre membrane module installed in…

Characterization of wastewater and biomass activity in a membrane bioreactor using respirometric techniques

Over the last two decades, Membrane Bioreactors (MBRs) emerged even more for wastewater treatment, ensuring high removal efficiencies as well as very small footprint required. Indeed, in this kind of process, a modification in biomass activity and viability can exist compared to that of a conventional activated sludge (CAS) process. In this context, respirometric analysis represents a reliable tool in order to evaluate the actual biomass kinetic parameters, to insert in mathematical models in the design phase, as well as to monitor the biomass viability, especially when these processes are operated with high sludge retention time (SRT) values. The paper presents some results of respirometri…

Wettability of flax/basalt reinforced composites during aging in salt spray conditions

Aim of this work was to investigate the wettability of natural fibres reinforced epoxy composites, subjected to aging tests performed on two different laminates. The first laminate was constituted by stacking ten layers of bidirectional flax fabrics. The second one was produced by replacing two external flax layers with two layers of basalt mat, for each side of the laminate. Both laminates were exposed to salt-fog environmental conditions, according to ASTM B 117 standard, for 60 days. The results of wettability were compared with those of the water uptake test. Moreover, an analysis of variance was performed in order to evaluate the significance of the parameters that influence the wettab…

THE INFLUENCE OF LANDFILL FEATURES AND SIDE SLOPES ON METHANE EMISSION RATES

Sanitary landfills for Municipal Solid Waste (MSW) disposal have been identified as one of the most important sources of methane (CH4) emissions; indeed, MSW contains a certain amount of biodegradable organic matter which undergoes anaerobic degradation resulting in the production of the so called landfill gas (LFG), which main component is typically represented by CH4. In general, LFG will escape through any faults in the landfill capping or in the LFG collection system. If the capping is not damaged, low quantities of LFG will be emitted through the permeable material that covers the disposed waste. On the other hand, some zones of the capping are often more permeable than others (e.g. si…

A model for wastewater organic removal and fouling development in a SMBR pilot plant.