100,571 research outputs found
Development of advanced analytical methods for the determination of emerging pollutants in environmental waters
No full textThis thesis work was focused on the analytical determination of emerging
pollutants in environmental water matrix, concerning preparative step and
analysis using Gas Chromatography coupled with Mass Spectrometry (GCMS).
The emerging pollutants are so defined because they have been
recognized only recently as pollutants and regulatory and monitoring plans
are not yet implemented at Italian and European level. Pharmaceuticals
and Personal Care Products (PPCPs) are considered emerging
contaminants, they describe a large class of chemical contaminants that
can originate from human usage and excretions and veterinary
applications. There are a large number of different substances used as
medicines, during and after treatment, humans and animals excrete a
combination of intact and metabolised pharmaceuticals, many of which are
generally soluble in water and have been discharged to the aquatic
environment with little evaluation of possible risks or consequences to
humans and environment. In addition, the chemicals that are components
of personal care products (PCPs) number in the thousands, the world’s
people consume enormous quantities of skin care products, dental care
products, soaps, sunscreen agents, and hair styling products. PCPs
continuously enter the wastewater after their regular use during showering
or bathing. Recent studies indicate the potential widespread occurrence on
low-level concentrations (ng-μg/L) of PPCPs in the aquatic environment.
Therefore, there’s critical need for efficient and reliable analytical methods
to address the occurrence concentrations, and fate of the PPCPs in
environment. GC-MS has been the basic tool for environmental analyses of
various organic pollutants and it has been the approach of this study choice
because of its superior separation and identification capabilities.
The activity has been concentrated on the development of sample
preparation procedures that could be fast, cost-effective and environmentfriendly
for the analysis of PPCPs. It’s known that sample pre-treatment
causes an analysis bottleneck that typically accounts for over 60% of the total analysis time. The work was focused on evaluation and optimization of
different extraction techniques for treatment of water matrix.
There are fundamentally two kinds of approach for parameters
optimization. One Factor At Time (OFAT) method involves the testing of
factors, or causes, one at a time instead of all factors are changed at once.
Even more people, prominent text books and academic papers currently
favour design of experiments (DOE) approach; it’s a statistically
multivariate method for screening and/or optimization of different factors at
the same time (multiple factors are changed at once). It shows several
relevant advantages over OFAT approach: it requires less runs for the
same (sometimes more) precision in effect estimation, it can estimate
interactions and it provides a knowledge (and optimal settings of factors) in
the whole experimental domain, where OFAT can miss them. For these
reasons this approach was chosen for several published works, using in
particular Central Composite Design (CCD) or Box-Behnken Design (BBD).
Two different extraction procedure have been studied: Solid Phase
Extraction (SPE) and Solid Phase Micro Extraction (SPME). The first
technique was evaluated in order to optimize extraction step of 25 PCPs,
including fragrances, PAHs, antioxidants, UV-filters, plasticizers, and
pesticides, from water, using OFAT approach. The optimized parameters
were different: SPE sorbent, type and volume of eluent, elution rate, and
evaporation procedure. The better recovery yield considering the totality of
PCPs were found extracting with a Strata-X SPE cartridge, using a volume
of 15 mL of Ethyl Acetate as solvent, operating with slow flow rate, and
evaporating at 40°C of temperature. Under these con ditions the procedure
achieves a recovery higher than 70% for most PCPs investigated (with
LOD ranged from 5 to 10 pg injected on GC), this result makes the
developed method suitable for comprehensive chemical profiling of PCPs in
various aqueous matrices. It is clear that higher recovery values can be
achieved only for selected PCPs using specific target-compound methods.
That it was done for method optimization for determination of two synthetic
phenolic antioxidants and their five main metabolites in water. This is the first published method dedicated solely to the determination of this
chemical class in water samples. The methodology was developed using
SPE approach with derivatization before GC-MS analysis. Extraction on 10
mg Oasis HLB cartridges provides a satisfactory enrichment factor for
environmental samples avoiding the need of solvent evaporation and
reducing SPE costs and organic solvent wastes. After extraction, polar
metabolites are derivatized with MTBSTFA to produce stable, less polar
analytes that are determined by GC-MS at low levels. The usage of two
surrogate internal standards results in a method providing good accuracy,
with relative recoveries between 80 and 110%, and limits of detection (2-44
ng/L). The application of the method to wastewater and river samples
showed BHT and BHT-Q as the compounds in higher concentrations in
wastewater (up to 800 ng/L) and the metabolites BHT-CHO and BHTCOOH
as the most resistant to water treatment, being at the 10-100 ng/L in
sewage and river samples. In this work the optimization was done with an
experimental design approach, using a Box-Behnken design (BBD). This
work was developed in collaboration with University of Santiago de
Compostela (E).
SPME technique was investigated in order to extract a mixture of several
PCPs, evaluating extraction time and temperature and desorption time and
temperature. A simple SPME method has been developed for the
simultaneous GC-MS determination of 23 PCPs (i.e. antioxidants, PAHs,
UV-filters, pesticides, fragrances, plasticizers, that display log Kow values >
3.2) at trace levels in water. An Inscribed Central Composite (CCI) design
approach was employed for investigate extraction temperature and time,
and desorption temperature and time. A direct immersion mode was used
for extraction from a fixed sample volume. The optimum SPME operating
conditions have been defined as: extraction time of 90 min at a temperature
of 80°C, desorption time of 11 min at 260°C. Under these conditions the
procedure provides low detection limits (<= ppb) and satisfactory
reproducibility (RSD%<=1%) for most of the PCPs investigated.
The analysis was then extended to more polar compounds, for a total of 21
PPCPs that display a range of log Kow between 1.2 and 6.4 (i.e. antiseptic,
antinflammatory drugs, estrogens, UV-filters) with the necessity of
derivatize the compounds before GC analysis. A on-fiber after extraction
approach was chosen for SPME derivatization, using silylation agent. The
derivatization can be performed in only 30.5 minutes with a very small
consumption of silylation reagent and without need of high temperature.
Under the optimized conditions of extraction, derivatization and desorption,
the procedure provides low detection limits (<= 1 ppb for the non polar
analytes and <=35 ppb for the derivatized ones) and satisfactory
reproducibility (RSD% <=10% or 20%) for most of the PPCPs investigated.
The PhD project, in his totality, was a logic progressive work, expanding the
study in term of kind of analytes studied, extraction techniques and
optimization approach. A preliminary and careful study was carried out in
order to properly understand the current situation and the possible research
developments of interest. The study was initially focused on less polar
analytes (PCPs), then extending to more polar ones (PPCPs). It was firstly
took in consideration the SPE technique, going to more innovative and
preferable on several points of view SPME. The expanded range (in
particular polarity range) of analytes makes necessary a derivatization step
before GC-MS analysis, for these reason the subsequent step was the
optimization of a method that includes SPME-derivatization. Also
considering the optimization approach, the work started using OFAT
optimization, this approach was left after the first work for the more
accurate and precise DOE.
These works led to development of multiresidual analytical method suitable
for the comprehensive analysis of this kind of pollutants in water matrix.
These methodologies may be the basis of water monitoring for temporal
and spatial changes
il patrimonio degli ex ospedali psichiatrici a 40 anni dalla legge "Basaglia"
No full textL’ Istat ha pubblicato recentemente il Rapporto sulla salute mentale; ciò che colpisce, alla luce del dibattito in corso sulla legge 180 nel quarantennale della sua entrata in vigore, è come in Italia esistano delle profonde differenze nei percorsi di cura della salute mentale da Regione a Regione. E' quindi interessante esplorare come mai gli ex ospedali psichiatrici a quaranta anni dalla legge Basaglia non hanno ancora un futuro
Gli ex ospedali psichiatrici a quaranta anni dalla legge Basaglia: un futuro ancora da realizzare
No full textA quaranta anni dalla legge n.180 del 13 maggio1976, meglio nota come “legge Basaglia” ritenuta tra le più avanzate dell’epoca in materia di assistenza psichiatrica, l’articolo vuole riaffermare l’interesse sul tema, sottolineando come sia stato lento (e di non semplice attuazione) il percorso che ha portato alla chiusura dei manicomi italiani e altrettanto lento (e non privo di ostacoli) il processo di riuso e valorizzazione delle strutture.
Dopo più di venti anni dalla chiusura degli ospedali psichiatrici (cfr. legge n.724 del 23/12/ 1996, che destinava gli ex-ospedali psichiatrici a reddito, attraverso la vendita anche parziale degli stessi (con diritto di prelazione da parte di enti pubblici) per l’attuazione degli interventi previsti dal progetto-obiettivo “Tutela della salute mentale”.
Le neo-Aziende USL si trovarono ancora oggi impreparate a gestire un processo di tale complessità anche a fronte di lacunose e frammentarie le notizie sull’entità di tale patrimonio, sull’attuale proprietà, sui vincoli, sullo stato di conservazione, sul valore e sulle potenzialità.
L’articolo, nell’alternarsi di “luci” ed “ombre”, riferisce alcune esperienze virtuose condotte in Italia applicazione della legge 180 sulla valorizzazione delle ex strutture manicomiali
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Organic fraction of municipal solid waste (OFMSW) utilization for bio-hydrogen production
No full text
Valorization of Wine Lees to Polyhydroxyalkanoates
No full textIn the last years, research focused on the conversion of waste biomasses, and several other residues into value-added products such as new materials and chemicals [1]. In particular, the valorization of winery waste has received significant attention. The International Organization of Vine and Wine’s report shows that, in 2020, about 5 million of tonnes of wine was produced only in Italy.
Wine lees, one of the main by-products of the wine industry, are a polluting substrate, and massive volumes (up to 0.3 million t) are indeed yearly produced in Italy. [2].
This work aims to exploit wine lees to obtain high-added value products. Although these residues have been already proposed for the recovery of compounds such as tartaric acid, ethanol, and antioxidants to reduce disposal costs [3], this is the first time that wine lees were explored as a substrate for the proficient microbial production of polyhydroxyalkanoates (PHAs), a completely biodegradable and biocompatible bioplastic.
With this purpose, the PHAs accumulation by Cupriavidus necator DSM 545, Hydrogenoflava pseudoflava DSM 1034, and Pseudomonas oleovorans DSM 1045, was studied in different growth conditions on Prosecco wine lees and PHAs were determined in bacterial biomass. C. necator DSM 545 displayed the highest performances with a CDW (cell dry weight) and PHAs content of 4.90 ± 0.41 g/L and 60.30 ± 3.97%, respectively.
Although fine-tuning fermentation parameters is needed to improve PHAs yields, these preliminary results pave the way for the future industrial exploitation of wine lees into bioplastics.
References
[1] A. P Gupte, M. Basaglia, S. Casella, & L. Favaro. Renewable and Sustainable Energy Reviews 167 (2022) 112673.
[2] M. Lucarini, A. Durazzo, G. Lombardi-Boccia, A. Romani, G. Sagratini, N. Bevilacqua, F. Ieri, P. Vignolini, M. Campo, & F. Cecchini, in Biorefinery Production Technologies for Chemicals and Energy A. Kuila and M. Mukhopadhyay (Eds.), 2020 p. 91
[3] A. De Iseppi, M. Marangon, S. Vincenzi, G. Lomolino, A. Curioni, & B. Divol. Lwt 136 (2021) 110274.
Acknowledgment
This work was partially supported by the University of Padova with the following research projects BIRD234877/23, DOR2352129, DOR2251254/22; DOR2107797/21, DOR2084579/20, DOR1928058/19, BIRD21070
BIOTECHNOLOGICAL APPROACH TO BIOETHANOL: SUBSTRATES, MICROBES AND PROCESSES.
No full textLa conversione di biomasse in etanolo rappresenta, almeno in parte, alternativa valida ed environmentally friendly ai combustibili fossili. L’impiego di mais o canna da zucchero si è rivelato di efficace applicazione, ma la loro coltivazione entra necessariamente in competizione con le aree destinate all’agricoltura convenzionale. In tale ottica i residui delle produzioni e delle trasformazioni agro-alimentari, così come l’enorme disponibilità di materiale ligno-cellulosico (almeno 20 miliardi di t/anno), costituiscono una risorsa importante sia in termini ecologici che economici.
Al fine di ottenere un processo industrialmente valido per la conversione di biomasse in etanolo occorre individuare microbi efficienti nel degradare i polisaccaridi e fermentare gli zuccheri semplici che ne derivano. Il miglioramento genetico e/o la costruzione di microrganismi ricombinanti capaci di elevate efficienze di conversione rappresenta dunque una linea strategica oggi seguita da numerosi gruppi di ricerca
Engineering Cupriavidus necator DSM 545 for the one-step conversion of starchy waste into polyhydroxyalkanoates
No full textStarch-rich by-products could be efficiently exploited for polyhydroxyalkanoates (PHAs) production. Unfortunately, Cupriavidus necator DSM 545, one of the most efficient PHAs producers, is not able to grow on starch. In this study, a recombinant amylolytic strain of C. necator DSM 545 was developed for the one-step PHAs production from starchy residues, such as broken rice and purple sweet potato waste. The glucodextranase G1d from Arthrobacter globiformis I42 and the α-amylase amyZ from Zunongwangia profunda SM-A87 were co-expressed into C. necator DSM 545. The recombinant C. necator DSM 545 #11, selected for its promising hydrolytic activity, produced high biomass levels with noteworthy PHAs titers: 5.78 and 3.65 g/L from broken rice and purple sweet potato waste, respectively. This is the first report on the engineering of C. necator DSM 545 for efficient amylase production and paves the way to the one-step conversion of starchy waste into PHAs
BIOCARBURANTI: CRITICITÀ E PROSPETTIVE
No full textI residui delle produzioni e delle trasformazioni agro-alimentari, così come l’enorme disponibilità di materiale ligno-cellulosico (almeno 20 miliardi di t/anno), costituiscono una risorsa importante sia in termini ecologici che economici. L’energia contenuta in tali biomasse può verosimilmente essere recuperata, consentendo nel contempo di risolvere anche problemi di smaltimento. In tale contesto la produzione di biocarburanti potrebbe rappresentare una valida opportunità, tant’è vero che la ricerca negli ultimi anni si è fortemente orientata verso lo sviluppo di sistemi virtuosi che includono la generazione di biogas e bioetanolo. A differenza del biodiesel e del bioetanolo di prima generazione per i quali le colture di piante oleaginose, di mais o di canna da zucchero rischiano di entrare in competizione con aree agricole destinate alla filiera alimentare, la produzione di biogas e di bioetanolo di seconda generazione rappresentano, almeno potenzialmente, una valida alternativa ai combustibili di origine fossile.
Al fine di ottenere un processo industrialmente valido per la conversione di substrati amilacei o lignocellulosici disponibili a costo basso o nullo, occorre individuare microbi efficienti nel degradare i polisaccaridi in essi contenuti e fermentare gli zuccheri semplici che ne derivano. Il miglioramento genetico e/o la costruzione di microrganismi ricombinanti capaci di elevate efficienze di conversione rappresenta dunque una linea strategica oggi seguita da numerosi gruppi di ricerca in tutto il mondo. L’impiego di microrganismi adeguati associato a tecnologie efficienti di pretrattamento del materiale originale potranno dunque consentire di passare dalla fase di sperimentazione a quella di scale-up, fino al definitivo sviluppo di un efficiente sistema industriale
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