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Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) such as paracetamol, diclofenac, and ibuprofen are frequently encountered in surface and ground water, thereby posing a significant risk to aquatic ecosystems. Our study reports the catalytic performances of nanosystems TiO2 -MexOy (Me = Ce, Sn) prepared by the sol-gel method and deposite...
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... In this case, mass transfer occurs through the chaotic contact of three phases and the problem of catalyst removal after the process arises. To address the above issues, specially designed absorption columns equipped with a catalytic packing bed represent a new class of devices for catalytic ozonation [66,67], gaining growing attention. ...
The urgent need for sustainable solutions to environmental challenges has led to significant research efforts towards innovative processes and technologies capable of addressing global issues such as carbon dioxide (CO 2 ) capture and valorisation as well as efficient water-reuse cycles. The majority of processes involved in CO2 conversion require highly active catalysts for practical implementation. Concurrently, wastewater treatment technologies, critical for achieving sustainable water reuse, often rely on complex multi-stage systems that incorporate advanced oxidation processes (AOPs). Optimising reaction conditions and exploring unconventional approaches to catalytic system design are crucial for enhancing the efficiency of these processes. Among the emerging solutions, the application of thin-film catalysts deposited by cold plasma onto various structured supports has shown promising potential for improving process performance to meet environmental goals. This paper discusses recent advancements in the development of thin-film nanocatalysts based on cost-effective transition metals. It highlights their application in gas-phase reactions, such as CO 2 hydrogenation to value-added products, as well as innovative uses in multiphase gas-liquid systems, including CO 2 capture in aqueous solvents and the ozonation of wastewater.
... Among AOPs, semiconductor-mediated photocatalysis has gained great significance due to its potential to mineralize, at ambient temperature and pressure, a wide range of recalcitrant OPs, resulting in their complete oxidation into harmless substances [17]. The materials designated to foster photocatalysis are metal oxide nanoparticles (NPs), with titanium dioxide (TiO 2 )-in particular, the anatase phase-being the material of choice [10,18,19]. The appeal of TiO 2 is emphasized by the possibility to either mold stand-alone filters or to produce thin-film nanocomposite membranes when dispersed in an adequate matrix, usually polymeric or carbon-based, resulting in an adsorbent able to purify industrial water from both inorganic pollutants (IPs) and OPs [20][21][22]. ...
This work reports the preliminary results of the development of composite self-assembling membranes obtained by the combination of reduced graphene oxide (rGO) with commercial Degussa P25 titanium dioxide (TiO2). The purpose is to demonstrate the possibility of combining, in the same self-standing material, the capability to treat wastewater containing both inorganic and organic pollutants by exploiting the established ability of rGO to capture metal ions together with that of TiO2 to degrade organic substances. Moreover, this study also investigates the potential photocatalytic properties of tionite (TIO), to demonstrate the feasibility of replacing commercial TiO2 with such waste-derived TiO2-containing material, fulfilling a circular economy approach. Thus, rGO-TiO2 and rGO-TIO composite membranes, 1:1 by weight, were prepared and characterized by SEM-EDX, XRD, thermogravimetry, as well as by Raman and UV-Vis spectroscopies to verify the effective and homogeneous integration of the two components. Then, they were tested towards 3-mg L^(−1) aqueous synthetic solutions of Fe^(3+) and Cu^(2+) ions to evaluate their metal adsorption ability, with values of the order of 0.1-0.2 mmol gmembrane^(−1), comparable or even slightly higher than those of pristine rGO. Finally, the ability of the composites to degrade a common organic pesticide, i.e., Imidacloprid®, was assessed in preliminary photocatalysis experiments, in which maximum degradation efficiencies of 25% (after 3 h) for rGO-TiO2 and of 21% (after 1 h) for rGO-TIO were found. The result of tionite-containing membranes is particularly promising and worthy of further investigation, given that the anatase content of tionite is roughly 1/6 of the one in commercial TiO2.
... With the increase in the consumption of pharmaceuticals and personal care products (PPCPs), the presence of these emerging contaminants in water, which causes irreversible damage to human health and the ecological environment, has now become a serious environmental burden [5,6]. Owing to their bioactive activity and hazardous toxic metabolites, PPCPs are considered to have a more negative impact on the environment and water quality than any other pollutants, and appear in surface waters, groundwater, sewage water treatment plants, and industrial wastewater, at concentrations ranging from the µgL −1 to ngL −1 [5][6][7][8]. ...
Catalytic ozonation is an important water treatment method among advanced oxidation
processes (AOPs). Since the first development, catalytic ozonation has been consistently improved in terms of catalysts used and the optimization of operational parameters. The aim of this work is to compare the catalytic activity of polyaniline (PANI) and thermally treated polyaniline (PANI 900) in the catalytic ozonation of ibuprofen solutions at different pH values (4, 7, and 10). Catalysts were thoroughly characterized through multiple techniques (SEM, Raman spectroscopy, XPS, pHPZC, and so on), while the oxidation process of ibuprofen solutions (100 mgL−1) was assessed by several
analytical methods (HPLC, UV254, TOC, COD, and BOD5). The experimental data demonstrate a significant improvement in ibuprofen removal in the presence of prepared solids (20 min for PANI 900 at pH10) compared with non–catalytic processes (56 min at pH 10). Moreover, the influence of solution pH was emphasized, showing that, in the basic region, the removal rate of organic substrate is higher than in acidic or neutral range. Ozone consumption mgO3/mg ibuprofen was considerably reduced for catalytic processes (17.55—PANI, 11.18—PANI 900) compared with the absence of catalysts (29.64). Hence, beside the ibuprofen degradation, the catalysts used are very active in the
mineralization of organic substrate and/or formation of biodegradable compounds. The best removal rate of target pollutants and oxidation by–products was achieved by PANI 900, although raw polyaniline also presents important activity in the oxidation process. Therefore, it can be stated that polyaniline–based catalysts are effective in the oxidation processes.
... It enters the environment through unchanged excretion in urine and feces or after undergoing transformations producing toxic metabolites (like N-Acetyl-p-benzoquinone imine, NAPQ). These metabolites pass into the food chain through the aqueous medium [5]. Several studies have shown chronic effects in aquatic organisms due to exposure to paracetamol for long periods of time, affecting their growth rate or reproduction rates [6,7]. ...
Two titania photocatalysts have been prepared using the sol-gel method using TiCl4 as a precursor, and two different alcohols, namely, ethanol or propanol (Et or Pr). The main aim of this work was to study the effect of the nature of the alcohol on the chemical, structural and photocatalytic properties for paracetamol photodegradation of the final solids. The TiCl4/alcohol molar ratio to obtain the corresponding alkoxides (TiEt and TiPr) was 1/10. These alkoxides were calcined at 400 °C to prepare the oxide catalysts (named as TiEt400 and TiPr400). Powder X-ray diffraction (PXRD) of the original samples showed the presence of anatase diffraction peaks in sample TiPr, while TiEt is a completely amorphous material. Contrary to commercial TiO2-P25, the PXRD diagrams of the calcined samples showed anatase as the exclusive crystalline phase in both solids. The specific surface area (SBET) of sample TiPr400 was larger than that of sample TiEt400, and both larger than that of TiO2-P25. The three solids have been tested in the photodegradation of paracetamol in aqueous solution. It has been established that the alcohol used influences the properties and catalytic activity of the final oxides. The synthesized solids exhibit a higher activity than commercial TiO2-P25, because of their structural characteristics and larger SBET.
Here we report on a large-scale fabrication and application of triphenylphosphine oxide (Ph3PO) thin films for catalytic nucleophilic substitution of alcohols under modified Appel conditions. We found a relationship between the fabrication conditions and the optical and catalytic properties of the resulting films. An increase in the fabrication temperature along with a decrease in the film thickness makes it possible to obtain both an optically high-quality surface and the most efficient structure for catalysis allowing to achieve 93% yield. The key features of the fabrication method proposed are an operationally simplicity, low catalyst loading up to 10 mol %, medium reaction times, mild conditions, and large-scale application.
