Tesi di Dottorato
https://hdl.handle.net/10955/10
2024-03-29T13:00:13ZAnalisi sismica non lineare di edifici con struttura in C.A. base fissa ed isolata in presenza di fenomeni di martellamento interno ed esterno
https://hdl.handle.net/10955/5465
Analisi sismica non lineare di edifici con struttura in C.A. base fissa ed isolata in presenza di fenomeni di martellamento interno ed esterno
Labernarda, Rodolfo; Conte, Enrico; Mazza, Fabio
Dottorato di Ricerca in
Scienze e Ingegneria dell’Ambiente, delle Costruzioni e dell’energia – SIACE. Ciclo XXXIII
2021-06-09T00:00:00ZExperimental investigation of system performance for combined desalination processes with membrane capacitive deionisation (MCDI)
https://hdl.handle.net/10955/5464
Experimental investigation of system performance for combined desalination processes with membrane capacitive deionisation (MCDI)
Cañas Kurz, Edgardo E.; Critelli, Salvatore; Gabriele, Bartolo; Figoli, Alberto; Hoinkis, Jan
The water supply in many coastal regions worldwide is affected by progressive salinization. Here,
the use of desalination technologies is a viable solution for obtaining freshwater. In this thesis,
two modular concepts for brackish water (BW) desalination by the use of membrane capacitive
deionization (MCDI) and low-pressure reverse osmosis (LPRO) were developed and tested at
laboratory and pilot-scales with two pilot plants installed in Vietnam. The two concepts were
developed by using computer-based calculations (software: WAVE) and evaluated in a
socioeconomic and environmental multi-criteria analysis.
The first plant consisting of subsurface arsenic removal (SAR) as pre-treatment and MCDI for
desalination was installed in Tra Vinh, in the Mekong Delta for the treatment of arseniccontaminated
groundwater with a concentration of total dissolved solids (TDS) of 1.65 g/L.
Results showed the feasibility of the modular concept for producing drinking water
(TDS<0.45 g/L) with a specific energy consumption (SEC) of <3 kWh/m³. The relationship
between feed salinity and specific ion removal of the MCDI was evaluated in real environment and
compared with laboratory experiments. The use of renewable energies such as solar and wind for
autonomous supply was proven feasible for these technologies.
The second pilot plant was installed in a riverine estuary in the region of Cần Giờ, where no access
to freshwater is available due to the progressive salinization of river water and groundwater.
Here, river water showed TDS concentrations of up to 25 g/L. The combined system consisted of
UF pre-treatment, LPRO and MCDI to produce drinking water and product water with TDS of
<0.45 g/L and <1.5 g/L, respectively with a total SEC of 5.8 kWh/m³. Additionally, the
performance of the LPRO was compared to seawater-RO (SWRO) in pilot trials, which showed a
SEC of 5.5 kWh/m³. Although the SEC of single-stage SWRO was lower, the separate production of
drinking and product water by LPRO+MCDI showed different advantages including a reduced SEC
of 5.2 kWh/m³ for product water and additional 0.6 kWh/m³ for drinking water. Finally, an
optimization of the LPRO+MCDI can be possible by increasing the desalination efficiency of the
MCDI, increasing the efficiency of LPRO-pump and the MCDI power supply, and by aiming at feed
water qualities with lower salinity.
Dottorato di Ricerca in
Scienze e Ingegneria dell’Ambiente, delle contruzioni e dell’energia – SIACE.
Ciclo XXXIII
2021-10-31T00:00:00ZIn search of genetic and epigenetic markers of human aging and longevity: a study in the Calabrian population
https://hdl.handle.net/10955/5463
In search of genetic and epigenetic markers of human aging and longevity: a study in the Calabrian population
Iannone, Francesca; Cerra, Maria Carmela; Rose, Giuseppina
Dottorato di Ricerca in Scienze della Vita.
CICLO XXXIII
2021-02-01T00:00:00ZTheoretical Models for Membrane Capacitive Deionization for the design of Modular Desalination Processes
https://hdl.handle.net/10955/5462
Theoretical Models for Membrane Capacitive Deionization for the design of Modular Desalination Processes
Hellriegel, Ulrich; Critelli, Salvatore; Gabriele, Bartolo; Figoli, Alberto; Hoinkis, Jan
Due to climate change, water scarcity will be exacerbated around the globe. To increase
the water availability in regions at risk, water desalination plants can be a solution. Especially
in rural areas, energy e cient technologies are needed so that an operation with
renewable energy as photovoltaic modules can be feasible.
Recent publications showed that the novel technology membrane capacitive deionization
(MCDI) can achieve a lower speci c energy consumption (SEC) than reverse osmosis
(RO), for brackish water desalination with salt concentrations below 2.5 g L-1.
There is still a gap in research between laboratory operation and applied commercial
scaled desalination, regarding experimental but also theoretical model studies. Therefore
the latter is elaborated in the present PhD thesis. Hereby, existing models are
reviewed, adapted and further developed to t to applied MCDI operation for drinking
water production.
Two dimensional nite element methods (FEM) modelling of ion transport, according to
the Gouy-Chapman-Stern theory for electrical double layers (EDL) as well as computational
uid dynamics (CFD) is combined with an adjusted semi-analytical modi ed
Donnan (mD) model, with a constant excess chemical potential att = 2:33 kT, for
the electrosorption of ions into porous active carbon electrodes. It predicts the e uent
salt concentration time-dependently for di erent inputs of applied electrical currents
Icell and voltages as well as inlet concentrations and volume ows. Applied MCDI operation
was optimized for drinking water production with practical experiments, which
support the evaluation of the theoretical ndings. The model ts to experimental data
for Icell = 20 A, however the equations for the voltage over the electrodes need to be
re-assessed so that the model ts for further input parameters.
A CFD model of the water ow through large scaled MCDI modules (> 50 pairs of
electodes) shows the need of constructing spacer thicknesses Sp small enough, to ensure
equal retention times of the water between the electrodes in the module, which is
important for stable diluate concentrations.
Furthermore, an analytical calculation tool is developed, by adjusting the mD model
and introducing an e ective salt adsorption capacity salt; , to predict the maximum
e cient charging time tmax,ch, removal- and recovery rate as well as SEC values for optimized
operation of applied MCDI processes. The model reaches an accuracy of 87% for
the prediction of salt removal, 86% for tmax,ch and 75% for SEC values, compared with
an experimental study and thus can be used to optimize the process design of applied
MCDI desalination plants.
Dottorato di ricerca in Scienze e ingegneria dell'ambiente delle costruzioni e dell'energia - SIACE
Ciclo XXXIII
2021-12-08T00:00:00Z