In this paper, copper oxide supported manganese oxide octahedral molecular sieves (CuO-OMS-2) composite was successfully synthesized and subsequently investigated for the degradation and mineralization of phenol via peroxymonosulfate (PMS) activation. It was confirmed that the incorporation of CuO significantly promoted multivalent metals transition and oxygen vacancies generation. At initial pH 5.
View Article and Find Full Text PDFNowadays, reaction mechanisms of photo-Fenton process with chelated iron are not yet clearly defined. In this study, five organic fertilizers were used as iron complexes to investigate the role of sunlight and oxygen in photo-Fenton at near neutral pH. UV absorbance and stability constant of each selected iron chelate is different, and this work demonstrates that these parameters affect the reaction mechanisms in SMX degradation.
View Article and Find Full Text PDFSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has challenged societies around the globe. Technologies based on ozone, a powerful oxidant, have been evaluated to inactivate this virus in aerosols and fomites. However, the high data diversity hinders the possibility of establishing a common ground for determining best practices for the use of these technologies.
View Article and Find Full Text PDFCombined sewer overflows (CSO), generated during the wet weather flow from the combination of the inflow and stormwater runoff in sewer system, result in an overflow of untreated wastewater from sewer system, which might ultimately contain different micropollutants (MPs). In this study, a coagulation-flocculation-sedimentation (CFS) pretreated CSO spiked with MPs was treated by catalytic ozonation using carbon, iron, and peroxide-based catalysts. The catalysts were characterized and their activity on MPs removal was studied at two different ozone (O) doses (5 and 10 mg L).
View Article and Find Full Text PDFNowadays photoactivation mechanism of titanium dioxide nanoparticles (TiO NPs) and reactive species involved in saline waters is not sufficiently established. In this study, TiO photocatalytic process under simulated solar irradiation was evaluated in synthetic seawater and compared with deionized water, using sulfamethoxazole (SMX) as model organic compound. For a TiO concentration of 100 mg L, SMX degradation resulted two times slower in seawater than in deionized water by the determination of their pseudo-first order rate constants of 0.
View Article and Find Full Text PDFOzonation combined with continuous addition of HO was studied as potential strategy for the effective abatement of ozone-resistant micropollutants from wastewater effluents. Oxidant doses within and beyond immediate ozone demand completion were tested. Through experiments involving the continuous addition of HO in a semi-continuous contactor, it was demonstrated that this new approach could lead to a 36 % reduction of the overall O needs for a constant HO/O molar ratio of 0.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
February 2019
This paper reports the degradation of 10 mg L Ametryn solution with different advanced oxidation processes and by ultraviolet (UV) irradiation alone with the main objective of reducing acute toxicity and increase biodegradability. The investigated factors included Fe and HO concentrations. The effectiveness of the UV and UV/HO processes were investigated using a low-pressure mercury UV lamp (254 nm).
View Article and Find Full Text PDFCytostatic drugs, used in chemotherapy, have emerged as new environmental contaminants due to their recurrent presence in surface waters and genotoxic effects. Yet, their degradability and environmental fate is largely unknown. The aim of this study was to determine the degradation kinetics of 16 cytostatic drugs, prioritized according to their usage and occurrence in hospital and wastewater treatment plants (WWTP) effluents, through the following laboratory scale processes: hydrolysis, aerobic biodegradation, UV-C photolysis, UV-C/HO and simulated solar radiation.
View Article and Find Full Text PDFThis study aims to determine the occurrence of 10 OPFRs (including chlorinated, nonchlorinated alkyl and aryl compounds) in influent, effluent wastewaters and partitioning into sludge of 5 wastewater treatment plants (WWTP) in Catalonia (Spain). All target OPFRs were detected in the WWTPs influents, and the total concentration ranged from 3.67 µg L(-1) to 150 µg L(-1).
View Article and Find Full Text PDFHydroponics culture greenhouses usually work in closed and semi-closed irrigation systems for nutrients and water-saving purposes. Photo-Fenton reaction has been revealed as an efficient way to depollute that kind of recycled effluents containing pesticides, even for high salinity concentrations. However, the inefficacy of organic matter chemical depletion imposes the use of a subsequent treatment.
View Article and Find Full Text PDFCalcium channel blockers (CCBs) are a group of pharmaceuticals widely prescribed to lower blood pressure and treat heart diseases. They have been frequently detected in wastewater treatment plant (WWTP) effluents and downstream river waters, thus inducing a potential risk to aquatic ecosystems. However, little is known about the behavior and fate of CCBs under UV irradiation, which has been adopted as a primary disinfection method for WWTP effluents.
View Article and Find Full Text PDFInterferences from many sources can affect photo-Fenton reaction performance. Among them, catalyst inhibition can be caused by the complexation and/or precipitation of iron species by the organic matter and salts present in the reaction media. This is the case of the oxidation of effluents containing organophosphorous fosetyl-Al.
View Article and Find Full Text PDFAntibiotics are pharmaceutical compounds widely used to treat a broad range of infections. These chemicals appear to be recalcitrant compounds when released to water systems, and their presence at the effluent of wastewater treatment plants and surface waters has been widely documented. Sulfamethoxazole (SMX), a sulfonamide commonly used to treat urinary infections, is one of them.
View Article and Find Full Text PDFWater Sci Technol
December 2010
This work is focused on the study of the suitability of the photo-Fenton process as a pretreatment for water highly contaminated with a methomyl commercial formulation in Advanced Greenhouses devices. Initial concentrations of reagents and pesticide were evaluated according to a central composite experimental design, with methomyl depletion and biocompatibility of the final effluent as response functions. A triad of optimal operation conditions could be determined, [Met.
View Article and Find Full Text PDFAqueous solutions of two important quaternary ammonium compounds--16-BAC (benzyl-dimethyl-hexadecylammonium-chloride) and 18-BAC (benzyl-dimethyl-stearylammonium-chloride)--were treated by the ozonation and photo-Fenton processes at different ozone doses and hydrogen peroxide concentrations, respectively. During the photo-Fenton experiments, two different types of lamps were used--a UV mercury vapor medium pressure lamp and a xenon lamp, which simulates solar radiation. The total organic carbon removal was monitored to follow the mineralization of the surfactants.
View Article and Find Full Text PDFA combined strategy of a photo-Fenton pretreatment followed by a Sequencing Batch Biofilm Reactor (SBBR) was evaluated for total C and N removal from a synthetic wastewater containing exclusively 200 mg L(-1) of the antibiotic Sulfamethoxazole (SMX). Photo-Fenton reaction was optimized at the minimum reagent doses in order to improve the biocompatibility of effluents with the subsequent biological reactor. Consequently, the pretreatment was performed with two different initial H(2)O(2) concentrations (300 and 400 mg L(-1)) and 10 mg L(-1) of Fe(2+).
View Article and Find Full Text PDFSulfamethoxazole (SMX) is a bacteriostatic antibiotic largely used for diverse types of illness. Its widely use in humans and even in animals releases unmetabolized and active metabolites that have a strong potential in terms of effect in organisms. In this work, 200 mg L(-1) solution of sulfamethoxazole was treated by ozonation at different pH.
View Article and Find Full Text PDFThe objective of this work was to study the abatement of 200mgL(-1) sulfamethoxazole (SMX) solution by means of photo-Fenton process. Biodegradability of the treated solutions was followed by the ratio biochemical oxygen demand at five days/chemical oxygen demand (BOD(5)/COD) and toxicity by Microtox and inhibition tests. Experiments with different initial concentration of H(2)O(2) were carried out.
View Article and Find Full Text PDFBezafibrate (BZF) is a lipid regulator largely used for the treatment of hyperlipidaemia. As a result of its wide use, unmetabolized BZF is released in the environment with potential toxic effects for aquatic living organisms. The results obtained in this work show that ozonation is an efficient method to degrade BZF: after 10 min of treatment (corresponding to a dose of 0.
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