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    Development of integrated membrane systems for the treatment of olive mill wastewater and valorization of highadded value bioproducts
    (2017-07-21) Bazzarelli, Fabio; Carbone, Vincenzo; Giorno, Lidietta; Piacentini, Emma
    Nowadays, it is well recognized that advanced clean technologies, able to work in mild conditions and with low energy input are necessary to face challenges in environment protection, ratio nal use of water, production of naturally derived stable bioactive compounds. Membrane technologies fulfill these requirements. Studies are necessary to tune materials and processes for specific applications. The treatment of wastewaters coming from olive oil production is among the critical issues in agro food industry. The present work promoted advances in the development of novel membrane systems for the treatment of olive mill wastewater (OM WW). Th e se waters represent a severe environmental problem due to their high organic load and phytotoxic and antibacterial phenolic compounds, which resist to biological degradation . Additionally, the large volume of OMWW produced in combination with the short discarding time, increases the importance for disposal of this waste. On the other hand, OMWW represents a significant source of polyphenols for health benefits , which can be revalorized and used for medical or agro alimentary purposes. They also represent novel environmentally friendly formulation for chemical m anufacturing. The development of new strategies for the disposal of these by products appears to be extremely useful from an environmental and economic point of view. An advantageous solution is to transform what until now was considered junk to be dispos ed of in resource to be exploited and from which to draw profi t, through the recovery of high added value natural products (bioproducts) and water. In this context, integrated membrane systems can permit the selective recovery of bioactive compounds, such as polyphenols as well as water recovering and purification Moreover, membrane technology is considered a powerful tool for the sustainable industrial development, being able to well respond to the goal of the process intensification strategy” in terms of reduction of the plant size, increase of the plant efficiency, reduction of energy consumption and environmental impact. Nevertheless, one drawback of m embrane filtration of OMWW is the membrane fouling that drastically reduces the process performance. Therefore, OMWW pretreatment upstream of membrane process is necessary to limit fouling phenomena and to increase filtration efficiency. In this thesis, a co mprehensive study from OMWW treatment to biophenols recovery and valorization and water purification by means of integrated membrane process was carried out. Initially, studies focused on the decrease the fouling phenomena. For this purpose, a novel strate gy for a suitable pretreatment of OMWW was identified that permitted to obtain the total removal of suspended solids, through the aggregation and flocculation of particles by maintaining the pH of OMWW at isoelectric point. Secondly, the research focused o n the assessment of the potentiality of OMWW treatment by microfiltration and ultrafiltration process at the laboratory scale. Different organic and inorganic membrane materials were investigated, evaluating the permeation flux and the performance in terms of TOC (Total organic carbon) and polyphenols rejection . Afterwards, processes for OMWW purification aimed at obtaining of biologically active fractions at high concentration as well as their encapsulation were developed. For this purpose pressure-driven membrane processes such as microfiltration (MF) and nanofiltration (NF) and a relatively new membrane operation such as osmotic distillation (OD) were developed on lab scale prototype to obtain and concentrate fractions; membrane emulsification (ME) was st udied for the encapsulation of concentrated fractions. For MF operation, the efficiency of an air back flushing cycle was evaluated to keep constant the permeate flux during the OMWW processing processing. The overall integrated membrane system produced an enriched fraction of polyphenols, as well as a water stream that can be reused for irrigation or membrane cleaning. The highly concentrated polyphenols produced by osmotic distillation, is used as functional ingredients for formulation of water in oil (W/O) emulsions by membrane emulsification. The pulsed back and forward ME has been selected as low shear encapsulation method because it is particularly attractive for the production highly concentrated microemulsions without causing coalescence. The best operative cond itions (transmembrane pressure, wall shear stress) to control particle size and size distribution and obtain high productivity (dispersed phase flux) have been investigated . Water in oil emulsions with a narrow size distribution and high encapsulation effi ciency were obtained. Furthermore, in the present work a n ovel procedure for encapsulation of olive polyphenols with high load into solid lipid particles using traditional method (rotor stator homogenizer) and membrane emulsification was studied. Finally, a productive scale plant of the integrated membrane system was developed and installed at olive mill. The plant included the pre filtration unit, microfiltration, nanofiltration and a further step represented by reverse osmosis. The reverse osmosis has bee n used at large scale instead of membrane distillation due to its higher technology readiness level. Overall, this productive scale plant system proved efficient for fully recovery of biophenols in the retentate stream as well as reclamation of purified wa ter.
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    Development of integrated membrane systems for the treatment of olive mill wastewater and valorization of highadded value bioproducts
    (2017-07-21) Bazzarelli, Fabio; Carbone, Vincenzo; Giorno, Lidietta; Piacentini, Emma
    Nowadays, it is well recognized that advanced clean technologies, able to work in mild conditions and with low energy input are necessary to face challenges in environment protection, ratio nal use of water, production of naturally derived stable bioactive compounds. Membrane technologies fulfill these requirements. Studies are necessary to tune materials and processes for specific applications. The treatment of wastewaters coming from olive oil production is among the critical issues in agro food industry. The present work promoted advances in the development of novel membrane systems for the treatment of olive mill wastewater (OM WW). Th e se waters represent a severe environmental problem due to their high organic load and phytotoxic and antibacterial phenolic compounds, which resist to biological degradation . Additionally, the large volume of OMWW produced in combination with the short discarding time, increases the importance for disposal of this waste. On the other hand, OMWW represents a significant source of polyphenols for health benefits , which can be revalorized and used for medical or agro alimentary purposes. They also represent novel environmentally friendly formulation for chemical m anufacturing. The development of new strategies for the disposal of these by products appears to be extremely useful from an environmental and economic point of view. An advantageous solution is to transform what until now was considered junk to be dispos ed of in resource to be exploited and from which to draw profi t, through the recovery of high added value natural products (bioproducts) and water. In this context, integrated membrane systems can permit the selective recovery of bioactive compounds, such as polyphenols as well as water recovering and purification Moreover, membrane technology is considered a powerful tool for the sustainable industrial development, being able to well respond to the goal of the process intensification strategy” in terms of reduction of the plant size, increase of the plant efficiency, reduction of energy consumption and environmental impact. Nevertheless, one drawback of m embrane filtration of OMWW is the membrane fouling that drastically reduces the process performance. Therefore, OMWW pretreatment upstream of membrane process is necessary to limit fouling phenomena and to increase filtration efficiency. In this thesis, a co mprehensive study from OMWW treatment to biophenols recovery and valorization and water purification by means of integrated membrane process was carried out. Initially, studies focused on the decrease the fouling phenomena. For this purpose, a novel strate gy for a suitable pretreatment of OMWW was identified that permitted to obtain the total removal of suspended solids, through the aggregation and flocculation of particles by maintaining the pH of OMWW at isoelectric point. Secondly, the research focused o n the assessment of the potentiality of OMWW treatment by microfiltration and ultrafiltration process at the laboratory scale. Different organic and inorganic membrane materials were investigated, evaluating the permeation flux and the performance in terms of TOC (Total organic carbon) and polyphenols rejection . Afterwards, processes for OMWW purification aimed at obtaining of biologically active fractions at high concentration as well as their encapsulation were developed. For this purpose pressure-driven membrane processes such as microfiltration (MF) and nanofiltration (NF) and a relatively new membrane operation such as osmotic distillation (OD) were developed on lab scale prototype to obtain and concentrate fractions; membrane emulsification (ME) was st udied for the encapsulation of concentrated fractions. For MF operation, the efficiency of an air back flushing cycle was evaluated to keep constant the permeate flux during the OMWW processing processing. The overall integrated membrane system produced an enriched fraction of polyphenols, as well as a water stream that can be reused for irrigation or membrane cleaning. The highly concentrated polyphenols produced by osmotic distillation, is used as functional ingredients for formulation of water in oil (W/O) emulsions by membrane emulsification. The pulsed back and forward ME has been selected as low shear encapsulation method because it is particularly attractive for the production highly concentrated microemulsions without causing coalescence. The best operative cond itions (transmembrane pressure, wall shear stress) to control particle size and size distribution and obtain high productivity (dispersed phase flux) have been investigated . Water in oil emulsions with a narrow size distribution and high encapsulation effi ciency were obtained. Furthermore, in the present work a n ovel procedure for encapsulation of olive polyphenols with high load into solid lipid particles using traditional method (rotor stator homogenizer) and membrane emulsification was studied. Finally, a productive scale plant of the integrated membrane system was developed and installed at olive mill. The plant included the pre filtration unit, microfiltration, nanofiltration and a further step represented by reverse osmosis. The reverse osmosis has bee n used at large scale instead of membrane distillation due to its higher technology readiness level. Overall, this productive scale plant system proved efficient for fully recovery of biophenols in the retentate stream as well as reclamation of purified wa ter.
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    Development of Tailored Hydrogel Composite Membranes for Application in Membrane Contactors
    (2017-07-11) Majidi Salehi, Shabnam; Pantano, Pietro; Curcio, Efrem; Di Profio, Gianluca; Fontananova, Enrica
    This work was performed during the period from November 2013 to May 2015 in the Institute on Membrane Technology (ITM-CNR) at the University of Calabria (UNICAL), under supervision of Prof. Efrem Curcio, Dr. Gianluca Di Profio and Dr. Enrica Fontananova, from May 2015 to December 2015 at Universidade Nova de Lisboa (UNL), under supervision of Prof. Joao Crespo and from March 2016 to September 2016 at the University of Chemistry and Technology (ICT) Prague, under supervision of Dr. Eng. Vlastmil Fila. The main objective of this study was to design and develop tailored hydrogel composite membranes for application in membrane contactors, in particular, membrane distillation and membrane crystallization. Among various methods for membrane surface functionalization, surface photo-initiated graft polymerization technique (at UNICAL) and surface coating by incorporating nanoparticles (at UNL) were investigated to fabricate tailored hydrogel composite membranes In the first year at the University of Calabria, various hydrogel composite membranes were prepared by using photo-initiated polymerization method. The possibility of fine tuning the porosity and the chemical nature of hydrogels, were implemented with the preparation of composites containing diverse hydrogel components (monomer and cross-linker) and ratio among them. The selection of hydrogel components was based on the possibility to obtain homogeneous and stable composites by using specific polymeric porous membranes as supports. The resulting composite membranes were characterized by electron scanning microscopy, surface chemistry analysis, swelling degree, ion exchange capacity and water contact angle measurements Furthermore, virgin and hydrogel composite membranes were used in membrane distillation and crystallization experiments and the performance improvement was evaluated. As a result, higher water-transfer flux and enhanced ion rejection than traditional MD membranes was observed in MD treatment of saline solutions. When such HCMs used in membrane assisted crystallization of carbonate calcium (biomineralization), a wide range of crystal morphologies, most of them displaying a polycrystalline or mesocrystalline structure, was obtained in a great variety of experimental conditions. We demonstrated that this composite provides the opportunity to fine control the delivery of additives to the gel network through the porous structure of both support membrane and hydrogel layer, thus affecting crystallization kinetics, and crystal morphologies In the second year of the study at Universidade Nova de Lisboa, hydrogel composite membranes with tailored surface roughness and patterning were designed to examine the influence of the topography of such composite membranes on the growth of protein crystals. Iron oxide nanoparticles (NPs) were used as topographical designers providing a good control of membrane surface roughness and patterning. Surface morphology and topography of the prepared membranes were characterized using electron scanning microscopy, profilometry analysis and contact angle measurements. Finally, their performance was evaluated in the crystallization of Lysozyme used as a model protein and the effect of surface chemistry and topography on the heterogeneous nucleation of lysozyme crystals was investigated. We demonstrated that roughness influences crystallization, but we also show that excessive roughness may be deleterious, since it increases the number of crystals formed at the expenses of crystal size. Therefore, there is an optimum value of roughness for the formation of a low number of well-faced crystals with a larger size In the third year at the University of Chemistry and Technology Prague, the modeling of membrane crystallization was studied. The main goal of this work was to develop general model of membrane crystallization process. The development of this model involved the fundamental theories and models in membrane process and crystallization engineering, especially the models described the mass and heat transfers in membrane module and the crystal size distribution (CSD) determined by both nucleation and crystal growth processes based on the concept of the population balance equation. The experimental results of this study, allows to achieve new insight to fabricate and develop the novel hydrogel composite membranes with proper properties and novel functionality for application in membrane distillation and membrane crystallization processes