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

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

Establishing the occurrence of major and minorglucosinolates in Brassicaceae by LC-ESI-hybrid linearion-trap and Fourier-transform ion cyclotron resonancemass spectrometry

Glucosinolates (GLSs) are sulfur-rich plant secondary metabolites which occur in a variety of cruciferous vegetables and among various classes of them, genus Brassica exhibits a rich family of these phytochemicals at high, medium and low abundances. Liquid chromatography (LC) with electrospray ionization in negative ion mode (ESI-) coupled to a hybrid quadrupole lineariontrap (LTQ) and Fouriertransformioncyclotronresonancemass spectrometer (FTICRMS) was employed for the selective and sensitive determination of intact GLSs in crude sample extracts of broccoli (Brassica oleracea L. Var. italica), cauliflower (B. oleracea L. Var. Botrytis) and rocket salad (Eruca sativa L.) with a wide range of contents. When LTQ and FTICR mass analyzers are compared, the magnitude of the limit of detection was ca. 5/6-fold lower with the FTICR MS. In addition, the separation and detection by LC–ESI-FTICR MS provides a highly selective assay platform for unambiguous identification of GLSs, which can be extended to lower abundance (minor) GLSs without significant interferences of other compounds in the sample extracts. The analysis of Brassicaceae species emphasized the presence of eight minor GLSs, viz. 1-methylpropyl-GLS, 2-methylpropyl-GLS, 2-methylbutyl-GLS, 3-methylbutyl-GLS, n-pentyl-GLS, 3-methylpentyl-GLS, 4-methylpentyl-GLS and n-hexyl-GLS. The occurrence of these GLSs belonging to the saturated aliphatic side chain families C4, C5 and C6, presumably formed by chain elongation of leucine, homoleucine and dihomoleucine as primary amino acid precursors, is described. Based on their retention behavior and tandem MS spectra, all these minor compounds occurring in plant extracts of B. oleracea L. Var. italica, B. oleracea L. Var. Botrytis and E. sativa L. were tentatively identified

Removal of Dexamethasone Sodium Phosphate (DSP) in liquid phase by Using Advanced Oxidation Processes (AOPs)

The occurrence and the fate of pharmaceuticals residues in wastewater treatment and in the environment has attracted an increasing interest during the last decade and have posed a new challenge to professionals for wastewater recovery as well as to the pharmaceutical industry. The removal of many of pharmaceutical compounds, during municipal wastewater treatment, has showed to be incomplete and unsuitable. As a result, residues of these compounds have been detected in surface waters in concentrations ranging from the ng L-1 up to the mg L-1 level. Advanced Oxidation Processes (AOP) are commonly designed to produce hydroxyl radicals (HO•) that react efficiently with most organic compounds present in the water. Photo-catalysis has emerged as viable alternative for removing micro-pollutants and other organic contaminants from surface, ground and wastewater. The catalyst used in this study was the semiconductor titanium dioxide (TiO2) chosen for its properties: high resistance to corrosion, low toxicity and low costs. The aim of this work was the application of photo-catalysis for the degradation of dexamethasone sodium phosphate (9-fluoro-11β,17-dihydroxy-16α-methyl-21-(phosphonooxy) pregna- 1,4-diene-3,20-dione disodium salt). This pharmaceutical compound is one of the most potent corticosteroids with anti- inflammatory and immunosuppressive properties. It has been widely used to treat inflammation, allergy and diseases related to adrenal cortex insufficiency. DSP is also known to reduce neointimal hyperplasia in arteries and has been used for coating drug- eluting stents for local drug delivery to prevent restenosis. Photochemical reactions were carried out by using a solar simulator and kinetic parameters were determined. Identification of the photoproducts was performed by liquid chromatography system coupled to a hybrid linear quadrupole ion trap (LTQ) – Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The standard solution used as control in the darkness did not show any significant degradation during the experimental time. Data of the DSP degradation fitted well a pseudo first order kinetic curve and the half-life was 30 min. Four photoproducts have been successfully identified

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

DİAZEPAM DEGRADATİON USİNG SOLAR PHOTOCATALYSİS

Benzodiazepine drugs are used all over the world for anxiety disorders, as anticonvulsants and anti-epileptics, and for terminally ill people as part of essential medicines list from the World Health Organisation (WHO). The WHO list includes diazepam, which is frequently found as residual pollutant in secondary effluents from wastewater treatment plants (WWTPs). Aiming at the complete removing of this substance from the aqueous environments, two experiments were carried out using Advanced Oxidation Process (AOPs) by simulated solar irradiation with or without TiO2 as catalyst. Photocatalysis was much efficient (half-life = 6 hours) than photolysis (half-life = 34 hours) giving a series of byproduct that were identified by an LC system coupled to a hybrid linear quadrupole ion trap (LTQ)-Fourier-transform ion cyclotron resonance (FT-ICR) mass spectromete

TiO2 and Active Coated Glass Photodegradation of Ibuprofen

Commercial non-steroidal anti-inflammatory drugs (NSAIDs) are considered as toxic to the environment since they induce side effects when consumed by humans or aquatic life. Ibuprofen is a member of the NSAID family and is widely used as an anti-inflammatory and painkiller agent. Photolysis is a potentially important method of degradation for several emerging contaminants, and individual compounds can undergo photolysis to various degrees, depending on their chemical structure. The efficiency oftitanium dioxide (TiO2) and photocatalysis was investigated for the removal of ibuprofen from the aquatic environment, and the performance of these different processes was evaluated. In heterogeneous photocatalysis, two experiments were carried out using TiO2 as (i) dispersed powder, and (ii) TiO2 immobilized on the active surface of commercial coated glass. The kinetics of each photoreaction was determined, and the identification of the photoproducts was carried out by liquid chromatography coupled with Fourier-transform ion cyclotron resonance mass spectrometry (LC-FTICR MS). The overall results suggest that the TiO2 active thin layer immobilized on the glass substrate can avoid recovery problems related to the use of TiO2 powder in heterogeneous photocatalysis and may be a promising tool toward protecting the environment from emerging contaminants such as ibuprofen and its derivativ

GRAPHICAL RESOLUTION OF HUMIC STRUCTURES

Advanced techniques have been recently used to obtain information on Natural Organic Matter (NOM). However, the current knowledge of the chemical structure of humic substances (HS) is still incomplete. These substances appear to be too complex mixtures of charged organic molecules, and their characterization remains one of the most stimulating challenges in modern environmental science. Knowledge of the chemical composition of NOM is of great importance for the definition of soil and water properties because it has a significant impact on the understanding of numerous molecular and global-scale processes. This study aims to apply two-dimensional graphical methods to resolve homologous series in mass spectra of humic extracts (Suwannee River, Nordic Aquatic, and Soil) obtained using FT-ICR / MS (Thermo LTQ FT, 7 Tesla) in negative ionization mode. Electrospray ionization (ESI) coupled with ultra-high resolution mass spectrometry offered by Fourier transformed ion cyclotron resonance (FT-ICR / MS) has emerged with great promise as it can provide an overview of the NOM composition and details on a molecular scale. NOM's very high-resolution FT-ICR spectra can be extremely complicated. These spectra usually contain many peaks at each nominal mass and thousands of peaks across the entire spectrum. Each peak can represent a chemically distinct compound. This complexity poses an analytical challenge to the study of spectra for structural interpretation. Two-dimensional graphing methods, such as Kendrick and van Krevelen graphs, have been successfully applied to very high-resolution mass spectra, allowing peaks to be sorted into complicated spectra from their homologous relatives across the mass range. In van Krevelen plots, ionic signals corresponding to structural similarities between homologous series of compounds involved in the loss or gain of functional groups are found on straight lines. We identified many interesting homologous regions and compared the three humic standards with each other. Finally, we recognized the structural relationships of the homologous series obtained through Kendrick graphs. The results showed homologous series in the Suwannee River and Nordic Aquatic samples compared to the soil-extracted samples (soil-FA and soil-HA). In particular, homologous series signals related to methylation/demethylation, hydrogenation/dehydrogenation, hydration/dehydration and oxidation/reduction processes were lower in the soil-FA van Krevelen diagrams. On the contrary, the differences were not so evident in all the homologous series for the soil-HA samples

Fatty acid neutral losses observed in tandem mass spectrometry with collision-induced dissociation allows regiochemical assignment of sulfoquinovosyl-diacylglycerols

A full characterization of sulfoquinovosyldiacylglycerols (SQDGs) in the lipid extract of spinach leaves has been achieved using liquid chromatography/electrospray ionization-linear quadrupole ion trap mass spectrometry (MS). Low-energy collision-induced dissociation tandem MS (MS/MS) of the deprotonated species [M - H]- was exploited for a detailed study of sulfolipid fragmentation. Losses of neutral fatty acids from the acyl side chains (i.e. [M - H - RCOOH]-) were found to prevail over ketene losses ([M - H - R'CHCO]-) or carboxylates of long-chain fatty acids ([RCOO]-), as expected for gas-phase acidity of SQDG ions. A new concerted mechanism for RCOOH elimination, based on a charge-remote fragmentation, is proposed. The preferential loss of a fatty acids molecule from the sn-1 position (i.e. [M - H - R1COOH]-) of the glycerol backbone, most likely due to kinetic control of the gas-phase fragmentation process, was exploited for the regiochemical assignment of the investigated sulfolipids. As a result, 24 SQDGs were detected and identified in the lipid extract of spinach leaves, their number and variety being unprecedented in the field of plant sulfolipids. Moreover, the prevailing presence of a palmitic acyl chain (16:0) on the glycerol sn-2 position of spinach SQDGs suggests a prokaryotic or chloroplastic path as the main route for their biosynthesis