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Adsorption properties of particles for environmental applications
Full text linkThe contaminants of emerging concerns (CECs) are defined by the United States
Geological Survey (USGS) as: “any synthetic or naturally occurring chemical or any
microorganism that is not commonly monitored in the environment but has the potential
to enter the environment and cause known or suspected adverse ecological and/or
human health effects.” In other words, CECs are any substances that can be suspected to
cause harm. Basically, they are substances used in human activities every day for all
kinds of purposes. Because they are so numerous, ubiquitous and chemically different,
they are frequently divided into categories that describe their purpose, use or other
characteristics. Some common categories are: pharmaceuticals, personal care products,
agricultural runoff (pesticides, pathogens and fertilizers), fuel-based-compounds,
chlorinated solvents, flame retardants (perfluorinatedalkyl compounds), plasticizers,
dyes and endocrine disruptors.
CECs are continuously entering water sources throughout the world because of their
widespread use. Conventional wastewater and recycled water treatments are only
partially effective in their removal or degradation, so they are discharged into the
environment with treated wastewater effluent, recycled water and wastewater plant
sludge. Other sources of CECs include industrial wastewater effluents, untreated
wastewater from manufacturing facilities, landfill leachates, effluents from poultry
farms and animal feeding facilities where veterinary drugs may be used.
Effects of CECs on human and ecosystem health are largely unknown and relatively
little is known about the ways they travel through the environment or how they may be
transformed or degraded during their residence time in the environment. Some studies
have shown that even very low exposure to certain CECs can have impacts on
biological systems. CECs are generally present at very low concentration in natural
waters.
Therefore, it is important on one hand to develop analytical methods able to detect these
molecules in accurate way to better evaluate their impact on the environment, and on
the other hand to enhance the efficiency of water remediation technologies in order to
decrease their potential adverse effects on biota. Several methods have been reported to
be suitable for both of these purposes; sorption based technologies were demonstrated
to be efficient and economical methods both for the enrichment of trace pollutants and
for their removal from water.
Among the large number of inorganic adsorbents, zeolites were proven to be efficient in
removing organic compounds from environmental matrixes. Recently, mesoporous
silica materials have also received increasing interest because their properties (high
surface area, high pore volume, controlled pore size) make them promising as
adsorbents in contaminant removal processes. Moreover, due to the thermal and
chemical stability of these siliceous adsorbents, they can be considered environmentally
compatible.
The aim of the present work is to study the adsorption properties of microporous (Beta,
ZSM-5, Y and ferrierite zeolites) and mesoporous (MCM-41 and HMS) siliceous
materials towards various organic compounds in aqueous solutions. This investigation
has the dual purpose of evaluating the application of the selected adsorbents both in
remediation technologies of natural waters and as medium for solid phase extraction
systems of pre-concentration.
For what concerns the studied contaminants, four compounds (ketoprofen,
hydrochlorothiazide, atenolol, erythromycin) have been selected as members of CECs.
These four drugs belong to different therapeutic classes and have been detected in
natural waters of several countries because they are not efficiently removed by
conventional wastewaters treatments plants. Moreover they are characterized by
different physico-chemical properties as molecular dimensions, acid/base behaviour,
hydrophobicity, ecc. Perfluorooctanoic acid (PFOA) was selected because, due to its
high water-solubility, it has been frequently found in aquatic environment; moreover it
is extremely persistent and toxic. The selected organic pollutants were toluene and
methyl-tert-butyl ether (MTBE): they were chosen as representative of BTEX (benzene,
toluene, ethylbenzene, xylene) and fuel oxygenate compounds, respectively. Because of
its high water solubility and hence high bioavailability, MTBE belongs to the class of
emerging contaminants too.
In this thesis, chromatographic, thermogravimetric and diffractometric techniques were
employed to study the adsorption process in order to: 1) investigate the adsorptive
properties of the siliceous materials; 2) characterise their structures after the adsorption
of the selected contaminants; 3) localise the organic species in the zeolites channel
systems; 4) probe the interactions between organic molecules and framework oxygen
atoms; 5) characterize the kinetic of the adsorption process.
In particular, the thermodynamics and kinetics of the adsorption process of
contaminants on hydrophobic zeolites were studied by using complementary
techniques: chromatography and thermogravimetry. Chromatography was mainly used
to measure the adsorption isotherms of the studied compounds. The adsorption isotherm
is useful for representing the capacity of a zeolite for adsorbing organics from water,
and in providing description of the functional dependence of capacity on the
concentration of pollutants. Experimental determination of the isotherm allows for
evaluating the feasibility of adsorption for treatment, in selecting a zeolite and in
estimating adsorbent dosage requirements. Moreover, from isotherm parameters it is
possible to evaluate the adsorption energy distribution of the process. The abovementioned
techniques were also employed to investigate the kinetics of the adsorption.
Kinetics deals with changes in chemical properties in time and is concerned especially
with rates of changes: hence it plays a fundamental role in determine the proper contact
time for the removal of pollutant components from wastewater. To investigate the
adsorption mechanism, diffraction techniques were employed to localize the organic
adsorbed into the zeolite structure. The information gathered by this last investigation –
in cooperation with the Earth Science Department UNIFE - allow to define the
interactions between organic molecules and zeolite framework.
The experimental data revealed that the amount of the organic pollutant embedded
inside the framework was influenced by the lattice structure, the hydrophobicity
(SiO2/Al2O3 ratio: SAR) and the thermal treatments of the adsorbent. For mesoporous
silica materials, an important role is also played by the procedure of template removal
(thermal treatment or solvent extraction).
Both hydrophobic and electrostatic interactions were demonstrated to contribute to the
adsorption process: in fact, hydrophobicity and dissociation constant of the solute
strongly affect the adsorption.
In many cases the selected molecule was proved to be adsorbed inside the framework of
the siliceous materials. Generally, it was also proved that the adsorption process was
very fast in all the studied zeolites towards several classes of pollutants. Also the
adsorption kinetic of PFOA on mesoporous silica materials was satisfying if compared
with literature data dealing with other types of adsorbents.
To investigate the possible competition of natural organic matter towards contaminants
adsorption, the effect of two lignin-derived phenolic monomers (caffeic acid and parahydroxybenzaldheyde)
with molecular dimensions comparable to those of the pores of
the adsorbent material on the adsorption properties of zeolites was considered. This last
part of the work of thesis is a fraction of a wider project whose purpose is to study the
interaction and mobility of groundwater pollutants adsorbed in zeolite pores in order to
improve the efficiency of permeable reactive barriers. This project involves Ferrara,
Bologna and Piemonte Orientale Universities with the financial and scientific support of
ENI Research Center of San Donato Milanese.
The results revealed that zeolites are selective adsorbents for organic pollutants. In fact,
it was demonstrated that toluene is preferentially and almost exclusively adsorbed from
mixtures of toluene and humic acid monomers in aqueous solutions.
In conclusion, favourable adsorption kinetics along with the effective and selective
adsorption of contaminants into zeolites and mesoporous siliceous materials make these
cheap and environmentally-friendly materials a tool with interesting applications for the
removal or enrichment of organic pollutants from contaminated waters
Job satisfaction, work-related stress and disability
No full textIn this paper, we investigate the impact of disability on job satisfaction and work-related stress
using the European Working Conditions Survey (EWCS, sixth wave). Employees with limitations
in daily activities related to their long-term illness or health problems are found to experience
lower job satisfaction and higher work-related stress. For these employees, a multivariate analysis
shows that future adaption of the workplace or work activities can affect work-related stress and
job satisfaction and that work-life balance has a higher impact than on the overall sample. These
results confirm the need to adopt organisational changes and workplace adaptations to make the
workplace more inclusive for people with disabilities. Perceived discrimination connected to one’s
disability status is also found to increase work-related stress among employees, calling for specific
actions to contrast and prevent stereotypes and direct discrimination in the workplace
Access to work and disability: the case of Italy
No full textThis paper is an empirical study on the access to work an important factor of social inclusion for people with disability. The focus is on Italy, a country characterized by lower activity rates than other industrialized countries together with the presence of a normative setting that supports the inclusion of disabled people in paid employment though characterized by regional heterogeneity in its implementation. Labour reforms recently increased retirement age in Italy, and aged workers could be more exposed to the risk of facing disabilities limiting participation into paid work. The results of the analyses on Health status and use of health services Istat microdata show a lower probability of being employed for people with disabilities and a higher positive effect of education on their employment probability than found for not disabled. The availability of data on the type of disability allows to detect a lower employment probability for psychic disabled
Disability and life satisfaction in Italy
No full textDuring the last decades, the socio-economic policy agenda has devoted an increasing attention to the inclusion of disabled people into society. It follows that understanding the drivers of life outcomes and conditions of disabled people is essential to analyze the sources of disadvantaged positions.
This paper brings evidence on the predictors of life satisfaction of disabled people in Italy, focusing on four specific dimensions (relations with relatives and friends, economic conditions, and leisure time) and analyzing information on people with functional limitations and health problems, as provided by the 2011 ISTAT survey.
Estimation results show that household structure, health and disability status affect life satisfaction more significantly than personal and income variables. Education attainments significantly affect satisfaction with the economic conditions. In addition, support in daily activities may increase satisfaction with economic conditions and leisure time, suggesting that providing non-monetary support would be effective in increasing life satisfaction, especially in those domains requiring freedom of movement.
Finally, we find that older disabled people are, on average, more satisfied than younger disabled people, while gender is relevant when interacted with the household
Patterns of Deindustrialization: Are Countries Converging?
Full text linkDuring the last decades, the share of manufacturing in aggregate output (and employment) has declined in almost all advanced and emerging economies. In this paper, we investigated the patterns of deindustrialization in a sample of 117 (low-, middle-, and high-income) countries from 1995 to 2018. To this aim, we applied the
nonlinear time-varying factor model, initially proposed by Phillips and Sul, to identify potential clubs wherein groups of countries converge toward a similar manufacturing share of GDP. Furthermore, we estimated an ordered logit model to assess the impact of economic globalization and technological revolution on the probability of falling into a particular club. Our results did not provide any support for the hypothesis of global
convergence. However, the clustering algorithm successfully identified four strong final clubs, where the share of manufacturing on GDP ranges, on average, from 6% to 18%. Finally, the logit model indicated that as the R&D expenditures and the technological content of manufactured goods increased, so did the likelihood of belonging to a club with a high share of manufacturing value-added on GD
Testing Club Convergence in Female Smoking Prevalence
Full text linkIn this paper, we applied the concept of convergence to examine the evolution of smoking prevalence among women in 191 countries worldwide from 1990 to 2019. First, the non-linear time-varying factor model proposed by Phillips and Sul was adopted to identify potential clusters (clubs), wherein groups of countries converge to similar female smoking rates. Second, an ordered logit regression model was used to assess the impact of cigarette affordability on the probability of falling within a given cluster. The hypothesis of global convergence was rejected. However, the clustering algorithm successfully identified five and nine clubs, within countries with increasing and decreasing smoking prevalence, respectively. A higher relative income-price ratio (i.e., lower cigarette affordability) increased the likelihood of belonging to a club of countries with a low prevalence of female tobacco smoking
Healthy life, social interaction and disability
Full text linkThis paper aims at analysing two relevant dimensions of well-being: living a healthy life and social interaction. A link between the two dimensions of well-being has been highlighted in the literature. The model assumes that both these concepts, i.e. social interaction and healthy life, are latent and manifest themselves through a number of indicators. The indicators adopted are those available in the 2011 ISTAT survey on social inclusion of people with disability in Italy by comparing the well-being attainments with respect to the different levels of functional limitations. In this paper the available indicators are used simultaneously to study the level of social interaction and health through a multiple indicators multiple causes model. This allows us to deal directly with endogeneity issues. Results show that women have a lower achievement in social interaction and in health. Moreover, differences occur in the effect of the observable exogenous variables included in the model with a larger negative effect of ageing for women on their health status and a higher negative effect of ageing for men on social interaction. Education plays a significant role only for women for the healthy life dimension. Finally, the latent variable on social interaction has been found to positively affect, consistently with the literature, the health dimension
Il costo della crisi in termini di salute mentale: il caso di Modena
No full textLa grande recessione ha causato costi tangibili in termini di tagli nell’occupazione e nella riduzione del reddito nei Paesi Europei. L’incertezza derivante dalla perdita del lavoro e l’espandersi di condizioni lavorative precarie sono state individuate in letteratura come possibili determinanti di una precaria salute mentale. La letteratura esistente sulla disoccupazione e la salute mentale mostra chiaramente una riduzione del benessere individuale durante il periodo di disoccupazione e un miglioramento dello stesso una volta ritrovato il lavoro. Questo studio mira ad identificare la relazione esistente tra lo stato di occupato e la salute mentale nella provincia di Modena che è stata colpita, oltre che dalla crisi economica, anche dal terremoto nell’anno 2012. I risultati, basati sull’analisi di due indagini sulle condizioni socio-economiche delle famiglie di Modena (ICESmo2 riferita all’anno 2006 e ICESmo3 riferita all’anno 2012), indicano un effetto negativo sulla salute mentale provocato dalla crisi, con una dimensione più grande di quella osservata nella media italiana. Inoltre, si osserva una riduzione dell’indice di salute mentale più accentuata per le donne e si registra un effetto negativo della disoccupazione sulla salute mentale e la residenza in un’area colpita dal terremoto
Determinazione mediante SPNE-MEKC di nucleosidi
No full textL'impiego di nanoparticelle d’oro (AuNPs) come mezzo adsorbente è una applicazione in rapida espansione a causa delle loro proprietà intrinseche che le rendono uno strumento molto promettente. A tal proposito, tali nanomateriali possono essere sintetizzati in una vasta gamma dimensionale (1-150 nm) con una limitata dispersione dimensionale, sulla loro superficie possono essere adsorbiti più agenti di targeting e/o terapeutici, infine il nucleo è atossico, biocompatibile e inerte [3].
Lo scopo del presente lavoro è stato quello di valutare l'interazione tra alcune molecole ad attività farmacologica, il cui interesse è dovuto alla loro attività farmacologica come farmaci antibiotici, antivirali e/o antitumorali, e le nanoparticelle d’oro (AuNPs) e di indagare l'applicabilità di queste NPs in sistemi di nano-estrazione in fase solida (Solid Phase Nano Extraction SPNE)
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