RESUMEN
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.
RESUMEN
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 deposited onto glass slides by a dip-coating approach in the removal of paracetamol from aqueous solutions by catalytic ozonation. The effect of catalyst type and operation parameters on oxidation efficiency was assessed. In addition to improving this process, the present work simplifies it by avoiding the difficult step of catalyst separation. It was found that the thin films were capable of removing all pollutants from target compounds to the oxidation products.
RESUMEN
The purpose of this work was to determine some aspects of micromorphology of total suspended particles (TSP) and particulate matter with aerodynamic diameter ≤10 µm (PM(10)) and their major elemental components in order to highlight the main characteristics of the atmospheric particles from an urban environment, having a case study in the urban area of Bucharest. The sampling of PM(10) and TSP were conducted in the close vicinity of a high traffic road for 72 h per sample and also priority pollutants in air: Pb and Cd were quantified and correlations between their concentrations and local wind directions were also found. The parameters characterizing the micromorphology of particle-roughness of the particle surface and area of particle-were correlated with wind direction.