100,458 research outputs found
Competitive adsorption of 4-hydroxybenzaldheyde (p-HBA) and toluene (TOL) by Y and ZSM-5 high-silica zeolites
No full textEVALUATION OF MOLLUSC SHELL POWDER AS BIOSORBENT FOR THE REMOVAL OF METAL IONS FROM POLLUTED WATERS
No full textINtech4Water “INtegrated TECHnologies for pollutants in (waste) WATER services"
No full textINTECH4WATER è un progetto che ha come obiettivo la depurazione, la valorizzazione e il riciclo di acque reflue provenienti da depuratori municipali e da processi industriali, in ottica di Circular Economy.
Il progetto prevede una integrazione di tecnologie innovative, sicure e sostenibili, per l’eliminazione dei contaminanti più comuni delle acque reflue (carichi di N e P, inquinanti emergenti, microplastiche, batteri patogeni per l’uomo).
Le tecnologie previste per la sperimentazione sono: filtri ceramici, fotocatalitici e adsorbenti, processi di ossidazione avanzata, UV, ozono e microalghe. Il progetto prevede due fasi: fase 1) di laboratorio, per identificare la migliore combinazione di tecnologie; fase 2) prototipale, per uno scale up delle ricerche e per testare il sistema su scala reale.
Tutti gli step saranno guidati da analisi statistiche avanzate (machine learning e intelligenza artificiale) e corredate da analisi chimiche, biologiche e microbiologiche.
L’idea di creare un nuovo sistema di tecnologie integrate per la depurazione, la valorizzazione e il riciclo di acque reflue di depuratori municipali e processi industriali ha l’obiettivo di migliorare l’efficienza del processo di rimozione degli inquinanti più comuni, chimici e biologici.
Il progetto INTECH4WATER è rivolto specialmente a realtà aziendali con elevata variabilità, nel corso dell’anno, della composizione del refluo, per cui una sola tecnologia di depurazione non può essere in grado soddisfare appieno la depurazione delle acque in uscita dagli impianti.
La possibilità di rendere più efficiente l’intero processo depurativo garantisce una migliore qualità delle acque rilasciate in corpi idrici naturali, con conseguente maggiore tutela della salubrità dell’ambiente e con un’evidente ricaduta positiva sulla salute umana
Adsorption of L-lysine on zeolites: effect of different framework topology and different Si/Al ratio
No full textThe study of the ability of zeolites to adsorb amino acids is significant to improve the knowledge of
the interactions between these molecules and solid surfaces. This is of fundamental importance to
increase the level of understanding of much more complex systems and to select adsorbent materials
able to selectively capture amino acids from aqueous solutions.[1]
Zeolites are aluminosilicate materials characterized by regular crystalline structure with microporous
cavities which confer a high superficial area. The physico-chemical proprieties of zeolites depend on
the composition of their framework that consist of tetrahedral units of SiO4 and AlO4 and, in
particular, their ratio (SAR) characterizes the hydrophilic/hydrophobic behavior of the material.
Moreover, the different conformation and dimension of the internal channels and cages influence the
adsorption selectivity towards host molecules.[2] The ability of zeolites to adsorb biologically active
biomolecules such as amino acids is of particular interest in industrial biotechnology[3] due to the fact
that these adsorbent materials could be used as solid solvents to stabilize the different charged forms
of the amino acids.
In this study we tested the different adsorption capacity of zeolites L and ZSM-5 towards the
amino acid L-lysine. These zeolites were chosen since they present different framework, with 2D and
3D channels structures, and different pore dimensions. Moreover, for the zeolite ZSM-5, two
materials having different SAR were selected to study the effect of zeolite chemical composition on
the adsorption capacity. Kinetic and isothermal experiments were carried out at different L-lysine
initial concentrations to study the adsorption processes. The results show high capacity towards the
adsorption of L-lysine for every zeolite investigated. We found a higher capacity for zeolite L with
respect to ZSM-5. Moreover, zeolite ZSM-5 with greater SAR has shown less adsorption, probably
a cause of different surface charge. [1][4] Moreover, the results obtained by thermal analyses (TGDTG-
DTA) showed different interactions within the amino acid-zeolite adduct and different stability,
depending on the peculiarities of the zeolites studied. Further investigation of the refinements of X
ray powder diffraction patterns showed the adsorption sites, the orientation and the interactions of the
amino acid molecules within the zeolite channels.
This work allowed to improve the understanding of the formation and interactions of the adducts
that originate from the adsorption of amino acids on zeolites. The information obtained are useful for
separation of amino acids from complex mixtures.
[1] G. Beltrami, A. Martucci, L. Pasti, T. Chenet, M. Ardit, L. Gigli, M. Cescon, E. Suard,
ChemistryOpen 2020, 9(10), 978–982.
[2] A. Martucci, L. Pasti, N. Marchetti, A. Cavazzini, F. Dondi, A. Alberti, Micropor. Mesopor. Mat.
2012, 148(1), 174-183.
[3] K. Stückenschneider, J. Merz, and G. Schembecker, J. Phys. Chem. 2014, 118, 5810-5819.
[4] T. Chenet, A. Martucci, M. Cescon, G. Vergine, G. Beltrami, L. Gigli, M. Ardit, M. Migliori, E.
Catizzone, G. Giordano, L. Pasti, Micropor. Mesopor. Mat., 2021, 323, 111183
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Multi-Omics and Genome Editing Studies on Plant Cell Walls to Improve Biomass Quality
No full textBiomass is one of the most important sources of renewable energy and plays an important role in reducing our reliance on fossil fuels. Efficient biomass production is essential to obtain large amounts of sustainable energy with minimal environmental cost. However, the biochemical and molecular processes behind the synthesis of the main components of biomass are still not fully understood. This review provides a comprehensive summary of the most relevant studies on cell wall biosynthesis and degradation mechanisms, focusing on the lignocellulosic component, in which the conversion process to fermentable sugars is expensive, due to its recalcitrant nature. A focus is placed on multi-omics research involving genomics, transcriptomics, proteomics, metabolomics, and phenomics, since multi-omics approaches offer a unique opportunity to investigate the biological pathways underlying the genotype traits characterizing cell wall energy crops. Furthermore, our study highlights the advances in genome editing approaches and proposes the modification of the genes that are involved in the complex cell wall structure as a feasible solution to an efficient biomass production. Several key points for future research activities based on these emerging technologies are also discussed, focusing on the combination of multi-omics and gene editing approaches, which offer potential for improved biomass valorization and the development of tangible bioproducts
Accumulation of trace metals in crayfish tissues: is Procambarus clarkii a vector of pollutants in Po Delta inland waters?
No full textConcentrations of trace elements (Cd, Pb, As, Cu and Zn) were determined in superficial sediments and in hepatopancreas, exoskeleton, and abdominal muscle of the red swamp crayfish Procambarus clarkii from several canals of the Po River Delta area. Sediments of the studied canals exhibited some metal pollution. The hepatopancreas of the crayfish showed a higher concentration of trace metals in comparison to the other tissues at all sites under scrutiny. Concentrations of As and Pb, either in sediment and P. clarkii tissues, were probably related to the use of fertilizers and pesticides. Moreover, the levels of certain metals accumulated in the abdominal muscle (Pb, Cu and Zn) exceeded the threshold values considered harmful to human health. The Toxic Contamination Index, depending on the bioaccumulation data of hepatopancreas and abdominal muscle, allowed us to assess the toxicity by heavy metals of sediments measuring the stress level of the detoxification organ, and resulted in >1 only at two sampling canals. We hypothesize that P. clarkii in the Po River Delta aquatic communities can act as a vector of pollutants, as crayfish can transfer their relatively high amount of heavy metals to higher trophic levels
Nanostructured carbon materials for the removal of PFAS from water matrices for environmental applications
No full textL−Lysine Amino Acid Adsorption on Zeolite L: a Combined Synchrotron, X-Ray and Neutron Diffraction Study
No full textCombined neutron and X-ray powder diffraction techniques highlighted the sorption capacity of the acidic L zeolite towards the L-lysine amino acid. The role of zeolite channels in the stabilization of the lysine absorbed and the effect of water on protein structure are elucidated at atomistic level. The stabilization of the L α-helical conformation is related to strong H-bonds between the tail aminogroups of lysine molecules and the Brønsted acid site as well as to complex intermolecular H-bond system between water molecules, zeolite and amino acid. This finding is relevant in the catalytic synthesis of polypeptide, as well as in industrial biotechnology by qualitatively predicting binding behaviour
Selective adsorption of toluene and n-hexane binary mixture from aqueous solution on zeolite ZSM-5: Evaluation of competitive behavior between aliphatic and aromatic compounds
No full textIn this study, high silica ZSM-5 was selected as an adsorbent for the removal of toluene (TOL) and n-hexane (HEX) binary mixtures from aqueous solution over a wide range of concentrations. In comparison with the single component systems, the binary mixture induced to a selective adsorption by the ZSM-5 zeolite. As a matter of fact, a selective adsorption, described by a competitive dual site Langmuir adsorption isotherm, is revealed where alkane compound is preferred to the aromatic one. Results from adsorption isotherm were related to the structural answer of the ZSM-5 framework as a function of a HEX-TOL equimolar binary mixture adsorption. Rietveld refinements provided information about the relative position of both molecules within the ZSM-5, and on the intermolecular distances between the adsorption sites of HEX and TOL. Residuals of electron density calculated by mean of delta Fourier maps indicated the presence of both guest molecules but with a clear indication of preferential towards n-hexane, and a clear differential adsorption site distribution. The occurrence of host-guest interactions in the narrow intracrystalline micropores between the solid catalyst and embedded molecules have been revealed
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