Publications by authors named "M Magureanu"

21 Publications

A review on non-thermal plasma treatment of water contaminated with antibiotics.

J Hazard Mater 2021 Feb 22;417:125481. Epub 2021 Feb 22.

GREMI, UMR 7344, Université d'Orléans, CNRS, Orléans, France.

Large amounts of antibiotics are produced and consumed worldwide, while wastewater treatment is still rather inefficient, leading to considerable water contamination. Concentrations of antibiotics in the environment are often sufficiently high to exert a selective pressure on bacteria of clinical importance that increases the prevalence of resistance. Since the drastic reduction in the use of antibiotics is not envisaged, efforts to reduce their input into the environment by improving treatment of contaminated wastewater is essential to limit uncontrollable spread of antibiotic resistance. This paper reviews recent progress on the use of non-thermal plasma for the degradation of antibiotics in water. The target compounds removal, the energy efficiency and the mineralization are analyzed as a function of discharge configuration and the most important experimental parameters. Various ways to improve the plasma process efficiency are addressed. Based on the identified reaction intermediates, degradation pathways are proposed for various classes of antibiotics and the degradation mechanisms of these chemicals under plasma conditions are discussed.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125481DOI Listing
February 2021

Characterization of the chemical activity of a pulsed corona discharge above water.

Chemosphere 2019 Dec 9;236:124302. Epub 2019 Jul 9.

Department of Plasma Physics and Nuclear Fusion, National Institute for Lasers, Plasma and Radiation Physics, Atomistilor Str. 409, P.O. Box MG-36, Magurele, Bucharest, 077125, Romania. Electronic address:

A pulsed corona discharge above liquid combined with ozonation has been investigated for the degradation of organic pollutants in water, as well as regarding the generation of several oxidizing species: ozone in gas phase, hydrogen peroxide and hydroxyl radicals in the liquid. A considerable improvement in the energy efficiency for organic compounds removal has been observed when reducing the width of the discharge pulses. This finding was correlated with the efficient formation of oxidizing species in case of short pulses. Recycling of the effluent gas from the plasma also enhances contaminants degradation. This was mainly attributed to an in situ peroxone process, i.e. the reaction between plasma-generated O and HO, forming highly reactive OH radicals, largely responsible for organic compounds degradation. This assumption is supported by the decline in O and HO concentrations and simultaneous increase in OH concentration detected in plasma-ozonation experiments as compared to results obtained with plasma alone.
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http://dx.doi.org/10.1016/j.chemosphere.2019.07.033DOI Listing
December 2019

Degradation of the chlorophenoxyacetic herbicide 2,4-D by plasma-ozonation system.

J Hazard Mater 2017 Aug 23;336:52-56. Epub 2017 Apr 23.

University of Bucharest, Faculty of Chemistry, Department of Organic Chemistry, Biochemistry and Catalysis, Bd. Regina Elisabeta 4-12, 030016, Bucharest, Romania.

A novel advanced oxidation process based on the combination of ozonation with non-thermal plasma generated in a pulsed corona discharge was developed for the oxidative degradation of recalcitrant organic pollutants in water. The pulsed corona discharge in contact with liquid, operated in oxygen, produced 3.5mgL ozone, which was subsequently introduced in the ozonation reactor. The solution to be treated was continuously circulated between the plasma reactor and the ozonation reactor. The system was tested for the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and considerably improved performance as compared to ozonation alone, both with respect to the removal of the target compound and to mineralization. The apparent reaction rate constant for 2,4-D removal was 0.195min, more than two times higher than the value obtained in ozonation experiments. The mineralization reached more than 90% after 60min treatment and the chlorine balance confirms the absence of quantifiable amounts of chlorinated by-products. The energy efficiency was considerably enhanced by shortening the duration of the discharge pulses, which opens the way for further optimization of the electrical circuit design.
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http://dx.doi.org/10.1016/j.jhazmat.2017.04.050DOI Listing
August 2017

Color Doppler imaging of the retrobulbar circulation in progressive glaucoma optic neuropathy.

Rom J Ophthalmol 2016 Oct-Dec;60(4):237-248

"Ghencea Medical Center" Bucharest, Romania.

It is known that elevated intraocular pressure (IOP) is the primary risk factor for glaucoma. Recently, more and more evidences have shown that the vascular deficit also plays an important role in the pathogenesis and progressions of glaucomatous optic neuropathy. This issue is backed up by glaucomatous optic neuropathy (GON) cases drug compensated in which the progression of the disease in one or both eyes is ascertained despite a normal and relatively constant IOP. The present study evaluated the hemodynamic parameters in the retrobulbar circulation in patients with progressive glaucomatous optic neuropathy in one eye, who received compensated medication. The hemodynamic parameters (PSV, EDV, IR) were measured by using color Doppler ultrasound and progression was evaluated by a repeated automated perimetry. The obtained values were statistically analyzed and compared with those obtained for the stable eye.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5711288PMC
May 2018

Survey on retrobulbar blood flow in glaucomatous optic neuropathy (normotensive and hypertensive).

Rom J Ophthalmol 2016 Oct-Dec;60(4):231-236

Ghencea Medical Center Bucharest, Romania.

The aim of this study was to analyze the possible differences between retrobulbar blood flows in normotensive glaucomatous optic neuropathy patients versus patients with hypertensive glaucomatous optic neuropathy, with intraocular pressure controlled treatment. All the patients in the study group were subjected to a color Doppler echography of retrobulbar vessels. Afterwards, systolic and diastolic blood velocities were measured in both eyes in ophthalmic artery (OA), central retinal artery (CRA) and posterior ciliary arteries (PCA). The device calculated the Resistivity index Pourcelot (RI) automatically.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5711287PMC
May 2018