L'inquinamento ambientale è cresciuto fino a diventare un problema che colpisce l'aria, l'acqua, il suolo e gli ecosistemi, principalmente a causa della crescita della popolazione mondiale in combinazione con un rapido sviluppo economico, che ha portato a un massiccio aumento della produzione globale. In effetti, è legato all'aumento dell'utilizzo e della complessità delle sostanze chimiche in molte attività umane. In particolare, l'ambiente acquatico globale è stato influenzato da sostanze chimiche antropogeniche ampiamente diffuse e, tra queste, i contaminanti di interesse emergente (CEC), compresi i prodotti farmaceutici e i prodotti per la cura personale, sono di particolare rilevanza poiché possono avere un impatto sulla vita acquatica e salute umana. CEC è un termine usato per descrivere sostanze chimiche sintetiche o presenti in natura o qualsiasi microorganismo che non è comunemente monitorato nell'ambiente ma ha il potenziale di entrare nell'ambiente e causare effetti negativi noti o sospetti. I principali gruppi di CEC sono prodotti farmaceutici, prodotti per la cura personale, interferenti endocrini, tensioattivi, contaminanti organici persistenti, additivi industriali e dolcificanti artificiali. Questi contaminanti sono difficili da rintracciare a causa della necessità di metodi di rilevamento specifici, sollevando la domanda su quanto tempo questi contaminanti siano prevalenti ell'ecosistema e come il processo di contaminazione possa essere invertito o ridotto. Inoltre, è improbabile che diversi CEC vengano rimossi dai processi convenzionali di trattamento delle acque reflue (WWT). Le tecnologie avanzate di trattamento delle acque reflue sono state identificate per essere efficaci nel trattamento delle acque contaminate, come la nanofiltrazione, l'osmosi inversa,l'ozonizzazione e l'ossidazione chimica. Tra le diverse soluzioni, l'adsorbimento, una tecnologia consolidata, è ancora considerata un metodo affidabile e robusto per purificare soluzioni acquose a basso costo e con alta efficienza. Uno dei principali vantaggi delle tecnologie basate sull'adsorbimento è che sono in grado di rimuovere i contaminanti in intervalli di concentrazione molto bassi, una condizione operativa in cui la maggior parte delle altre tecniche di separazione sono scarsamente efficienti a causa dei piccoli gradienti di concentrazione coinvolti. Inoltre, l'adsorbimento è un metodo versatile che può rimuovere contemporaneamente molti diversi composti organici e inorganici, a condizione che venga impiegata una miscela adatta di materiali adsorbenti.Questa tesi si è concentrata sulla valutazione di diverse strategie per rimuovere gli inquinanti dalla matrice acquosa. In particolare, abbiamo studiato metodi basati sull'adsorbimento, e in questo caso sono stati selezionati materiali adsorbenti diversi tra loro per struttura, composizione chimica e condizioni operative, che possono essere suddivisi in due classi: (i) adsorbente microporoso silico alluminato (zeoliti) e (ii) membrane a matrice mista a base di carbonio (MMM). In questa tesi sono state studiate le proprietà adsorbenti delle zeoliti verso diverse classi di CEC (farmaci, PFAS e contaminanti organici) in soluzioni acquose al fine di studiare l'efficienza di questi materiali silicei in due applicazioni, ovvero: (1) la rimozione di contaminanti da matrice acquosa, (2) la fase di pre-concentrazione per l'analisi dei microinquinanti. Inoltre, sono state studiate anche le proprietà di adsorbimento MMM verso i composti perfluorurati. Le MMM sono composti da una fase polimerica continua e da una carica inorganica dispersa. Questa tesi include uno studio sui processi di ossidazione avanzati per la degradazione di prodotti farmaceutici in ambiente acquoso. In particolare sono stati studiati due diversi fotocatalizzatori: (i) decatungstato di sodio e (ii) triossido di tungsteno, questi semiconduttori hanno la capacità comune di fotoprodurre radicali .OH in soluzioni acquose.

Environmental pollution has grown to become a problem affecting air, water, soil and ecosystems, mainly due to the growth of the world population in combination with rapid economic development, which has led to a massive increase of global production. Indeed, it is linked to the increased use and complexity of chemicals in many human activities. In particular, the global aquatic environment has been affected by widely spread anthropogenic chemicals and, among these, contaminants of emerging interest (CEC), including pharmaceuticals and personal care products, are of particular relevance as they can have a impact on aquatic life and human health. CEC is a term used to describe synthetic or naturally occurring chemicals or any microorganisms that are not commonly monitored in the environment but have the potential to enter the environment and cause known or suspected adverse effects. The main groups of CEC are pharmaceuticals, personal care products, endocrine disruptors, surfactants, persistent organic contaminants, industrial additives and artificial sweeteners. These contaminants are difficult to trace due to the need for specific detection methods, raising the question of how long these contaminants are prevalent in the ecosystem and how the contamination process can be reversed or reduced. Furthermore, several CECs are unlikely to be removed from conventional wastewater treatment (WWT) processes. Advanced wastewater treatment technologies have been identified to be effective in treating contaminated water, such as nanofiltration, reverse osmosis, ozonation and chemical oxidation. Among the different solutions, adsorption, an established technology, is still considered a reliable and robust method to purify aqueous solutions at low cost and with high efficiency. One of the main advantages of adsorption-based technologies is that they are capable of removing contaminants in very low concentration ranges, an operating condition in which most other separation techniques are poorly efficient due to the small concentration gradients involved. . Furthermore, adsorption is a versatile method that can remove many different organic and inorganic compounds at the same time, provided a suitable blend of adsorbent materials is employed.This thesis focused on evaluating different strategies for removing pollutants from the aqueous matrix. In particular, we have studied methods based on adsorption, and in this case we have selected adsorbent materials different from each other in terms of structure, chemical composition and operating conditions, which can be divided into two classes: (i) microporous silica aluminate adsorbent (zeolites) and (ii) carbon-based mixed matrix (MMM) membranes. In this thesis the adsorbing properties of zeolites towards different classes of CEC (drugs, PFAS and organic contaminants) in aqueous solutions were studied in order to study the efficiency of these siliceous materials in two applications, namely: (1) the removal of contaminants from aqueous matrix, (2) the pre-concentration phase for the analysis of micropollutants. Furthermore, the properties of MMM adsorption towards perfluorinated compounds were also investigated. MMMs are composed of a continuous polymeric phase and a dispersed inorganic filler. This thesis includes a study on advanced oxidation processes for the degradation of pharmaceutical products in an aqueous environment. In particular, two different photocatalysts have been studied: (i) sodium decatungstate and (ii) tungsten trioxide, these semiconductors have the common ability to photoproduce .OH radicals in aqueous solutions.

CHARACTERIZATION OF NANOSTRUCTURED ADSORBENT MATERIALS FOR ENVIRONMENTAL APPLICATIONS

STEVANIN, Claudia
2022-02-25T00:00:00+01:00

Abstract

Environmental pollution has grown to become a problem affecting air, water, soil and ecosystems, mainly due to the growth of the world population in combination with rapid economic development, which has led to a massive increase of global production. Indeed, it is linked to the increased use and complexity of chemicals in many human activities. In particular, the global aquatic environment has been affected by widely spread anthropogenic chemicals and, among these, contaminants of emerging interest (CEC), including pharmaceuticals and personal care products, are of particular relevance as they can have a impact on aquatic life and human health. CEC is a term used to describe synthetic or naturally occurring chemicals or any microorganisms that are not commonly monitored in the environment but have the potential to enter the environment and cause known or suspected adverse effects. The main groups of CEC are pharmaceuticals, personal care products, endocrine disruptors, surfactants, persistent organic contaminants, industrial additives and artificial sweeteners. These contaminants are difficult to trace due to the need for specific detection methods, raising the question of how long these contaminants are prevalent in the ecosystem and how the contamination process can be reversed or reduced. Furthermore, several CECs are unlikely to be removed from conventional wastewater treatment (WWT) processes. Advanced wastewater treatment technologies have been identified to be effective in treating contaminated water, such as nanofiltration, reverse osmosis, ozonation and chemical oxidation. Among the different solutions, adsorption, an established technology, is still considered a reliable and robust method to purify aqueous solutions at low cost and with high efficiency. One of the main advantages of adsorption-based technologies is that they are capable of removing contaminants in very low concentration ranges, an operating condition in which most other separation techniques are poorly efficient due to the small concentration gradients involved. . Furthermore, adsorption is a versatile method that can remove many different organic and inorganic compounds at the same time, provided a suitable blend of adsorbent materials is employed.This thesis focused on evaluating different strategies for removing pollutants from the aqueous matrix. In particular, we have studied methods based on adsorption, and in this case we have selected adsorbent materials different from each other in terms of structure, chemical composition and operating conditions, which can be divided into two classes: (i) microporous silica aluminate adsorbent (zeolites) and (ii) carbon-based mixed matrix (MMM) membranes. In this thesis the adsorbing properties of zeolites towards different classes of CEC (drugs, PFAS and organic contaminants) in aqueous solutions were studied in order to study the efficiency of these siliceous materials in two applications, namely: (1) the removal of contaminants from aqueous matrix, (2) the pre-concentration phase for the analysis of micropollutants. Furthermore, the properties of MMM adsorption towards perfluorinated compounds were also investigated. MMMs are composed of a continuous polymeric phase and a dispersed inorganic filler. This thesis includes a study on advanced oxidation processes for the degradation of pharmaceutical products in an aqueous environment. In particular, two different photocatalysts have been studied: (i) sodium decatungstate and (ii) tungsten trioxide, these semiconductors have the common ability to photoproduce .OH radicals in aqueous solutions.
CAVAZZINI, Alberto
PASTI, Luisa
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11392/2488253
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