Aqueous solutions of four pharmaceutical compounds, belonging to the group of emergent contaminants of water: atenolol (ATL), hydrochlorothiazide (HCT), ofloxacin (OFX) and trimethoprim (TMP), have been treated with different oxidation systems, mainly, photocatalytic oxidation, ozonation and photocatalytic ozonation. TiO2 has been used as semiconductor for photocatalytic reactions both in the presence of air, oxygen or ozone-oxygen gas mixtures. Black light lamps mainly emitting at 365 nm were the source of radiation. In all cases, the influence of some variables (concentrations of semiconductor, ozone gas and pharmaceuticals and pH) on the removal of pharmaceuticals, total polyphenol content (TPC) and total organic carbon (TOC) was investigated. A discussion on the possible routes of pharmaceutical and intermediates (as TPC and TOC) elimination has been developed. Thus, OFX TiO2/UVA degradation mechanism seems to develop through the participation of non-hydroxyl free radical species. Furthermore, the presence of OFX inhibits the formation of hydroxyl radicals in the photocatalytic process. The most effective processes were those involving ozone that lead to complete disappearance of parent compounds in less than 30 min for initial pharmaceutical concentrations lower than 2.5 mg L(-1). In the ozonation systems, regardless of the pH and the presence of TiO2, pharmaceuticals are degraded through their direct reaction with ozone. Photocatalytic ozonation was the most efficient process for TPC and TOC removals (≥ 80% and ≥60% elimination after 2 h of treatment, respectively) as well as in terms of the ozone consumption efficiency (1, 5.5 and 4 mol of ozone consumed per mol of TOC mineralized, at pH 4, 7 and 9, respectively). Weakly acid conditions (pH 4) resulted to be the most convenient ones for TPC and TOC removal by photocatalytic ozonation. This was likely due to formation of hydroxyl radicals through the ozonide generated at these conditions.
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http://dx.doi.org/10.1016/j.jenvman.2013.04.024 | DOI Listing |
J Colloid Interface Sci
December 2024
State Key Laboratory of Photocatalysis On Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, PR China. Electronic address:
The development of durable and highly efficient visible-light-driven photocatalysts is essential for the photocatalytic ozonation process towards degrading organic pollutants. This study presents CN-MA, a novel photocatalyst synthesized by grafting carbon nitride (CN) with single-atom Mn and 2-hydroxy-4,6-dimethylpyrimidine (HDMP) via one-step thermal polymerization. Experimental characterization and theoretical calculation results reveal that incorporating single-atom Mn and HDMP into CN alters the charge density distribution on the heptazine rings.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Research Group on Sustainability and Quality of Fruit and Vegetable Production. Instituto Murciano de Investigación y Desarrollo Agrario y Medioambiental. C/ Mayor s/n. La Alberca, 30150, Murcia. Spain. Electronic address:
The reuse of treated wastewater for agricultural irrigation has enlarged the risk of pharmaceutical compound accumulation in soil and their potential translocation to crops. Therefore, it is necessary to apply effective techniques to remove these pollutants from soil. This work was aimed to study the effectiveness of two advance oxidation processes (photocatalysis and ozonation) in the degradation of carbamazepine (CBZ) residues in three different soil matrices.
View Article and Find Full Text PDFSci Total Environ
December 2024
Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa. Electronic address:
Microplastics (MPs) pollution has emerged as a global environmental concern due to its detrimental impacts on ecosystems. Conventional wastewater/water treatment methods are inadequate for MPs removal due to their diminutive size ranging from micrometers to nanometers. Advanced oxidation processes (AOPs) have gained attention as a promising green strategy for the efficient and safe elimination of MPs from aqueous systems.
View Article and Find Full Text PDFSci Rep
October 2024
Institute of Functional Interfaces (IFG), Microbiology/Molecular Biology Department, Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
Antibiotics are extensively used in human medicine, aquaculture, and animal husbandry, leading to the release of antimicrobial resistance into the environment. This contributes to the rapid spread of antibiotic-resistant genes (ARGs), posing a significant threat to human health and aquatic ecosystems. Conventional wastewater treatment methods often fail to eliminate ARGs, prompting the adoption of advanced oxidation processes (AOPs) to address this growing risk.
View Article and Find Full Text PDFJ Environ Sci (China)
March 2025
Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Oxidation of organic amines (OAs) or aromatic hydrocarbons (AHs) produces carbonyls, which further react with OAs to form carbonyl-amine condensation products, threatening environmental quality and human health. However, there is still a lack of systematic understanding of the carbonyl-amine condensation reaction processes of OAs or between OAs and AHs, and subsequent environmental health impact. This work systematically investigated the carbonyl-amine condensation coupled ozonolysis kinetics, reaction mechanism, secondary organic aerosol (SOA) formation and cytotoxicity from the mixture of dipropylamine (DPA) and styrene (STY) by a combined method of product mass spectrometry identification, particle property analysis and cell exposure evaluation.
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