Bio-strategie innovative per il “cleaning” e la “remediation” del patrimonio lapideo e metallico

Il patrimonio culturale è l'insieme di cose, dette più precisamente beni, che per particolare rilievo storico culturale ed estetico sono di interesse pubblico e costituiscono la ricchezza di un luogo e della relativa popolazione.Al fine di consentire alle prossime generazioni di massimizzare la fruizione del patrimonio storico-culturale, è necessario, oltre al controllo dei fattori responsabili del degrado, l’acquisizione di strategie di pulizia e successiva protezione dei beni innovative, efficaci, di lunga durata, ecocompatibili ed economicamente convenienti. Tecniche innovative attualmente adoperate sono la pulitura criogenica e l’utilizzo di biocidi a basso impatto ambientale Biocidi = estratti naturali di piante che a differenza dei prodotti di sintesi, risultano efficaci a basse concentrazioni nei confronti degli organismi biodeteriogeni, non interferiscono con il materiale costitutivo dell’opera , salvaguardano la salute degli operatori del settore e l’ambiente

Innovative methods for the recycling and reuse of contaminated water: the Nanowat project

Proposals for the reuse of alternative waters are of growing interest for regions stressed by scarce water availability. Collection, treatment and redistribution are some of the phases that require different purification actions, actions related to the water origin (eg. gray, rain, and/or industrial waters). It is known that wastewater contains both chemical and microbiological contaminants and for this reason, it is essential to have reliable control tools for assessing both risks (chemical and microbiological) for which, often, there is a lack of clear and comprehensive reference standards. NANOWAT project ( Diffusion of nanotechnology based devices for water treatment and recycling) has focused attention on the development and diffusion in the Mediterranean area of new technologies for efficient water treatment based on natural and modified nano-materials, using either filtration and sedimentation, photo-degradation, photocatalysis and their combination. Pilot-scale mobile equipment for the treatment of different types of wastewater like pesticides, pharmaceuticals, and organic contaminants coming from industrial enterprises was developed and realized. In detail was carried out the filtration using both nano-structured clay-micelles and clay vesicles to facilitate the immobilization of organic pollutants, microfibers and micro-plastics and successively on the recalcitrants compounds, still contained in the liquid phase after filtration treatment, were performed new photo-catalytic processes based on TiO2 in suspension and/or on immobilized on glass. Results obtained were interesting and effective, however confirming the need to customize the wastewater purification procedure in relation to the type of contamination present

Progress on the removal of contaminants on surface and wastewater: report of case-studies

Contamination of the water sector represents a global issue known since the 1960s. However, the consequences are still not adequately known as a whole. There is insufficient information on the thousands of molecules released into the environment and, above all, their properties and the quantities produced, capable of determining the global effects of potential toxic actions on living organisms and the environment. For some time, scholars and researchers from the planet have been directing their activities to identify new integrated technologies and low energy consumption tools aimed at treating and reusing wastewater. For some time, our research group has been experimenting with removing traditional contaminants and emerging contaminants using hybrid techniques (filtration and Advanced Oxidation Processes). In this communication, we report some of our case studies, which have validated the effectiveness of the treatments

PHOTOCHEMICAL BEHAVIOUR OF OXYFLUORFEN: A DIPHENYL-ETHER HERBICIDE

The photochemical behaviour in different solvents of the herbicide oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene (CAS RN 42874–03–3)] was studied. Photochemical reactions were carried out by using a high pressure mercury arc and a solar simulator. Kinetic parameters and quantum yields were determined. Identification of the photoproducts was performed by GC-MS and the main compounds were confirmed by [1H] NMR. The photochemical reactions were also carried out in the presence of either a singlet or a triplet quencher, and in the presence of either a radical initiator or a radical inhibitor. Results indicate that the first excited singlet state can undergo both homolytic and heterolytic cleavage of the ethyl-oxygen bond in the side chain of oxyfluorfen. Moreover, the presence of reduction products in the reaction mixture is supposed to occur via a monoelectron transfer process with the formation of a transient exciplex during the reaction

Multi-technique instrumental approach for the characterization of metallic archeological artifacts

The study of the grave goods has long been the subject of study by many researchers who, through the finds, try to reconstruct the habits and customs of disappeared civilizations. In particular, the characterization of metal artifacts (weapons, jewelry, everyday objects) allows to identify the source of the raw materials used for their manufacture, forging technologies, trade routes, and cultural interactions [1,2]. The aim of this preliminary study was, by using a multi-technique instrumental approach (XRD, Raman, XPS, XRF), the chemical-mineralogical characterization of archaeological metal finds (figure 1) from the necropolis of Siris - Heraclea (Basilicata region). The analyzes highlighted, in some of these objects, the presence of a superficial state of alteration confirming what was reported by [3]. We are carrying out biological analyzes in order to verify the presence of biological agents, which, if present, could have triggered the corrosion processes. REFERENCES [1] Pernicka E., (2004) Archaeometallurgy: examples of the application of scientific methods to the provenance of archaeological metal objects. Proc. International School Physics “Enrico Fermi”, Course CLIV, (Martini M., Milazzo M. and Piacentini M., Eds.), IOS Press Amsterdam, 309- 329. [2] Tykot R.H., (2004) – Scientific method and applications to archaeological provenance studies. Proc. International School Physics “Enrico Fermi”, Course CLIV, (Martini M., Milazzo M and Piacentini M., Eds.), IOS Press Amsterdam, 407-432. [3] Afonso S. F., Noto M. M. M., Mendonça M. H., Pimenta G., Proença L., Fonseca I. T. E., “Copper corrosion in soil: influence of chloride contents, aeration and humidity”, J. Solid State Electrochem, Vol. 13, pp. 1757-1765 (2009)

The mechanism of the amine-catalysed isomerizationof dialkyl maleate: A computational study

DFT at B3LYP/6-31G (d,p) level calculation results for the amine-catalysed isomerization of dimethyl maleate revealed that the mechanism proceeds via foursteps: (1) a concerted proton transfer from one amine molecule to another which subsequently enhances the addition of the adduct thus formed to the C-C double bond to yield INT1. (2) Abstraction of a proton from the -carbon of INT1 by a second amine molecule to give intermediate INT2. (3) Rotation about the C-C single bond followed by proton abstraction by an amine molecule to yield unstable INT3, and (4) an elimination of an amine molecule to yield the trans isomer, dimethyl fumarate. Furthermore, it was found that step 1 is the rate limiting step. However, the activation energy difference between steps 1 and 2 was significantly low and its value depends on the amine catalyst used. The activation energy was found to be lower in water when compared to that calculated in the gas phase. In addition, linear correlation was found between the amine-catalysed isomerization experimental rate and the pKa of the amine catalyst on one hand and the enthalpic and free activation energies on the other hand. The calculations also confirmed that the reaction is first order in dimethyl maleate, second order in the amine catalyst and overall third order. This study disproves three of the four different intermediates that were previously suggested to explain the amine catalysed isomerization of dialkyl maleates. The study verifies the intermediate suggested by Rappopor

ADSORPTION OF TRIBENURON-METHYL BY NATURAL AND MODIFIED CLAYS

This work deals with the purification of water containing residues of the herbicide tribenuron-methyl by means of a cleaning system based on a composite organo-clay mineral. Tribenuron-methyl suffers hydrolysis, for this reason it is important to clean the water not only from the mother molecule, but also from the products of its degradation. Experiments on adsorption/desorption of tribenuron-methyl and its metabolites by using natural and organo-micellar montmorillonite were performed. Desorption of the herbicide from the micelle clay-composite was done using acetonitrile

Assay of riboflavin in sample wines by capillary zone electrophoresis and laser-induced fluorescence detection

To routinely assay the concentration of riboflavin (RF) in wines, a rapid and sensitive method was developed and evaluated. The method is based on a simple sample preparation, capillary zone electrophoretic separation and laser-induced fluorescence detection (CZE-LIF). Sample-preparation required only dilution and filtration. Under optimized conditions, the limit of detection of riboflavin was 0.5 mug/L, using a hydrodynamic sample introduction of 10 s at 54 mbar. The method was fully validated: the recovery of RF in wines was >95%. The concentrations of RF within the three sample types of Italian wines investigated here ranged from 69 to 151 mug/L with a mean value(+/-SD) of 112 +/- 25 mug/L, from 74 to 193 mug/L with a mean value of 115 +/- 45,ug/L, and from 156 to 292 mug/L with a mean value of 226 +/- 40 mug/L, for white, rose and red wines, respectively. Such an accurate and highly sensitive CZE-LIF method represents a powerful improvement over previous methods in terms of sensitivity, simplicity, and efficiency. It is well suited to satisfy the demands for accurate and sensitive detection with minimal sample preparation and cleanup

Artificial Aging of Crude Oil and Water Remediation by AOPs

Crude oil in the environment is exposed to a series of weather-climatic factors (water, oxygen, solar irradiation) and microorganisms’ action that triggers chemical-physical processes of degradation (known as weathering). In a short time, the original composition of exposed oil can change significantly. In this work, our research team experimented with an Italian crude oil simulating solar irradiation to understand the modifications induced on its composition by artificial aging. Moreover, we studied the transformations deriving from different advanced oxidation processes (AOP) applied as remediation methods on liquid matrices contaminated by petroleum. For the last objective, we adopted different AOPs (photocatalysis, sonolysis, and sonophotocatalysis). as a photocatalyst, we used TiO2 immobilized on a non-woven fabric sheet. Crude oil and its water-soluble fractions were analyzed using GC-MS, 1H-NMR in a liquid state, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and fluorescence. The artificial oil aging induced significant modifications of oil composition with the formation of more oxidized species. All treatments used for the detoxification of polluted water samples, except sonolysis, showed a consistent reduction of organic content with the appearance of potentially toxic substances, confirming that the remediation processes experimented with cannot be applied in natural environments without a careful and repeated experimentation in controlled laboratory conditions

Artificial Aging of Crude Oil and Water Remediation by AOPs

Crude oil in the environment is exposed to a series of weather-climatic factors (water, oxygen, solar irradiation) and microorganisms’ action that triggers chemical-physical processes of degradation (known as weathering). In a short time, the original composition of exposed oil can change significantly. In this work, our research team experimented with an Italian crude oil simulating solar irradiation to understand the modifications induced on its composition by artificial aging. Moreover, we studied the transformations deriving from different advanced oxidation processes (AOP) applied as remediation methods on liquid matrices contaminated by petroleum. For the last objective, we adopted different AOPs (photocatalysis, sonolysis, and sonophotocatalysis). as a photocatalyst, we used TiO2 immobilized on a non-woven fabric sheet. Crude oil and its water-soluble fractions were analyzed using GC-MS, 1H-NMR in a liquid state, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and fluorescence. The artificial oil aging induced significant modifications of oil composition with the formation of more oxidized species. All treatments used for the detoxification of polluted water samples, except sonolysis, showed a consistent reduction of organic content with the appearance of potentially toxic substances, confirming that the remediation processes experimented with cannot be applied in natural environments without a careful and repeated experimentation in controlled laboratory conditions