Browsing by Subject "Emerging pollutants"

Now showing 1 - 4 of 4
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    Magnetic core‑modified silver nanoparticles for ibuprofen removal: an emerging pollutant in waters
    (Nature Research, 2020-10-26) Vicente Martínez, Yésica; Solana González, Ruben; Soto Meca, Antonio; Caravaca, Manuel; Química Analítica
    In this work we present a novel procedure for ibuprofen adsorption from waters employing magnetic core-modified silver nanoparticles. We demonstrate that 93% adsorption of ibuprofen is achieved in 45 min by means of a simple method, for neutral pH and room temperature, also using a low dose of adsorbent, equal to 7 mg in 500 �L of suspension. The characterization of the adsorbent, before and after adsorption, was carried out by means of field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, BET analysis, Fourier-transform infrared spectroscopy and differential scanning calorimetry. It is worth pointing out that ibuprofen can be desorbed and the adsorbent can be reused, remaining unaltered for the first three cycles, and showing 89.3% adsorption efficiency after the third regeneration. A three-parameter model and the Langmuir isotherm characterize the kinetics and isotherm of adsorption.
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    Prediction of Flux and Rejection Coefficients in the Removal of Emerging Pollutants Using a Nanofiltration Membrane
    (2023-11-01) Hidalgo, A.M.; Gómez, M.; Murcia, M.D.; Gómez, E.; León, G.; Alfaro, I.; Ingeniería Química
    The removal of three emerging pollutants: carbamazepine, ketoprofen, and bisphenol A, has been studied using the nanofiltration flat sheet membrane NF99HF. The removal efficiencies of the membrane have been evaluated by two system characteristic parameters: permeate flux and rejection coefficient. The influence of two operating variables has been analysed: operating pressure and feed concentration. Before and after the tests with emerging pollutants, the membrane has been characterized by determining its water permeability coefficient and its magnesium chloride rejection coefficient to find out if the removal of emerging pollutants causes membrane fouling. The results show that operating pressure has significant separation effects, obtaining the highest efficiencies at a pressure of 20 bar for pollutant concentrations between 5 and 25 mg/L. Moreover, rejection of ketoprofen was found to be dependent on electrostatic repulsion, while rejection of bisphenol A was significantly affected by adsorption onto the membrane. Finally, the experimental data have been fitted to the solution diffusion model and to the simplified model of Spiegler-Kedem-Katchalsky to predict the behaviour of the nanofiltration membrane in the removal of the tested pollutants. Good agreement between the experimental and predicted carbamazepine and bisphenol A data has been obtained with each model, respectively.
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    Reclamation of aqueous waste solutions polluted with pharmaceutical and pesticide residues by biological-photocatalytic (solar) coupling in situ for agricultural reuse.
    (Elsevier, 2022) Pérez-Lucas, Gabriel; El Aatik, Aldo; Aliste, Marina; Hernández, Virginia; Fenoll, José; Navarro, Simón; Química Agrícola, Geología y Edafología
    This work focuses on the detoxification of aqueous waste solutions polluted with 24 emerging pollutants (13 pharmaceuticals and 11 pesticides) using a coupled biological-photocatalytic facility under natural sunlight for use in crop irrigation. The polluted wastewater (urban, agricultural, and industrial) processed by conventional wastewater treatment plants is in some cases insufficient to reach the degree of purity required. This concern is of particular interest, especially in areas where a low rainfall pattern provides insufficient water resources to meet the demands caused by agriculture, which requires increased reuse of wastewater effluents. For this purpose, polluted water was first subjected to biological treatment followed by a photocatalytic process using the tandem TiO2/Na2S2O8. Residues of pharmaceuticals and pesticides were isolated by solid phase extraction (SPE) and analysed by HPLC-QqQ-MS2. A notorious removal of pharmaceuticals was observed after biological treatment (average removal = 78%), except for diclofenac (31%) and carbamazepine (1%). In a contrary way, biodegradation of pesticides was inconspicuous (average removal = 48%) due to their recalcitrant properties. However, all compounds were rapidly degraded during the photocatalytic treatment because the fluence (H) required to obtain 90% degradation (H90) was<470 kJ m−2 for the most persistent pollutant (terbuthylazine). Single first order kinetic model satisfactorily explained the photooxidation of all micropollutants. Therefore, solar heterogeneous photocatalysis is presented as a promising technology to be incorporated as a tertiary process in wastewater treatment plants to remove biorecalcitrant pollutants. This implementation could be interesting especially in arid and semi-arid areas characterised by water scarcity but receiving many hours of sunshine per year, where a high percentage of reclaimed water is used for crop irrigation.
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    Using pressure-driven membrane processes to remove emerging pollutants from aqueous solutions
    (2021-04-12) Hidalgo, A.M.; León, G.; Murcia, M.D.; Gómez, M.; Gómez, E.; Gómez, J.L.; Ingeniería Química
    Currently, there is great concern about global water pollution. Wastewater generally contains substances called emerging pollutants, and if the removal of these pollutants is not given sufficient attention, the pollutants can enter into the water cycle and reach the water supply for domestic use, causing adverse effects on the well-being of people. In order to avoid this menace, a multitude of techniques to reduce the high concentration levels of these substances dissolved in water are being researched and developed. One of the most-used techniques for this goal is the physical-chemical separation of contaminants in water through membrane technology. In this study, different membranes were tested with the objective of investigating the removal of three emerging pollutants: caffeine, metformin, and methyl-paraben. Initially, a nanofiltration (NF) membrane was selected, and the influence of pressure was evaluated in the rejection coefficients and permeate fluxes. Next, a screening of three new membranes to remove methyl paraben was completed. The influence of the operating variables, working pressure, and methyl paraben-feed concentration was checked. Finally, the solution-diffusion model was applied to predict the behavior of the different membranes in the removal of methyl paraben. A good correlation between experimental and calculated values of permeate flux and methyl paraben concentration was obtained.