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Andrei Ionut Simion

Bio: Andrei Ionut Simion is an academic researcher from University of Rennes. The author has contributed to research in topics: Medicine & Aqueous solution. The author has an hindex of 7, co-authored 15 publications receiving 99 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the photodegradation efficiency of a refractory emergent compound, named clofibric acid, under UV light in aqueous solution was evaluated and it was shown that photode degradation and mineralization efficiency are strongly dependent on the catalyst used.
Abstract: Emerging pollutants such as pharmaceutical active compounds were detected worldwide in different environmental compartments. Nowadays, multiple studies are focused on the investigation of their environmental fate, as well as to find new, efficient and sustainable removal technologies. Several studies demonstrated that heterogeneous photocatalysis is one of the most promising techniques used for water purification. Thus, the aim of our work was to evaluate the photodegradation efficiency of a refractory emergent compound, named clofibric acid, under UV light in aqueous solution. We report that photodegradation and mineralization efficiency are strongly dependent of the catalyst used. Results showed that the photodegradation was enhanced in the presence of TiO2 Aeroxide. The complete elimination was achieved for an initial pollutant concentration of 1.5 mg/L after 30 min of irradiation, the degradation rate following the pseudo-first order kinetics. It was also observed that the rate constant for the photodegradation process is affected by the concentration of catalyst. Process efficiency is enhanced by increasing the light intensity. The simultaneous reduction of pollutant concentration and dissolved organic carbon demonstrates the mineralization of the target molecule. Furthermore, it was demonstrated that the addition of nitrate to the system increases the pollutant degradation rate, while the carbonate reduces its removal, suggesting that this last ion can act as a hydroxyl scavenger. Preliminary phytotoxicity tests were also carried out and showed the capacity of the heterogeneous photocatalysis to reduce the toxicity of reaction intermediates generated during the photocatalytic reaction.

28 citations

Journal ArticleDOI
TL;DR: In this article, the primary metabolite of a lipid regulator drug, clofibrate, identified in many studies as refractory during conventional wastewater treatment, was used to demonstrate new evidence of the efficient destruction and mineralization of an emergent organic pollutant using UV-A and titanium nanosized catalysts.
Abstract: This work demonstrates new evidence of the efficient destruction and mineralization of an emergent organic pollutant using UV-A and titanium nanosized catalysts. The target compound considered in this work is the primary metabolite of a lipid regulator drug, clofibrate, identified in many studies as refractory during conventional wastewater treatment. The photocatalytic performance study was carried out in batch mode at laboratory scale, in aqueous suspension. Kinetic data showed that titanium dioxide P25 Aeroxide (R) exhibits the highest photocatalytic efficiency compared to the other investigated catalysts. Pollutant degradation and mineralization efficiencies strongly increased when decreasing the initial substrate concentration. Target molecules oxidized faster when the catalyst load increased, and the mineralization was enhanced under acidic conditions 92% of mineralization was achieved at pH 4 after 190 min of reaction. Radical quenching assays confirmed that HO center dot and (hvb(+)) were the reactive oxygen species involved in the photocatalytic oxidation of the considered pollutant. In addition, further results revealed that the removal efficiency decreased in real water matrices. Finally, data collected through a series of phytotoxicity tests demonstrated that the photocatalytic process considerably reduces the toxicity of the treated solutions, confirming the process's effectiveness in the removal of persistent and biorefractory emergent organic water pollutants.

19 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of some fundamental operating parameters in heterogeneous photocatalysis were investigated in order to determine the main ones affecting the degradation kinetics of carbamazepine (CBZ).
Abstract: The present work systematically investigates the photocatalytic degradation of carbamazepine (CBZ), an organic compound, known as refractory to the conventional wastewater treatment by the titanium dioxide PC 500 catalyst. The effects of some fundamental operating parameters in heterogeneous photocatalysis were investigated in this work in order to determine the main ones affecting the degradation kinetics. The obtained results clearly showed that the removal rate of the target compound is strongly influenced by the initial concentration of the pollutant. The degradation reaction rate increases when the concentration of CBZ decreases due to a lower OH/CBZ ratio. On the other hand, it was shown that during the first 30 minutes the reaction of photocatalytic degradation follows a first order kinetic and also that when the incident light flux increases, the photocatalytic degradation process is accelerated due to the increases of the catalyst excitation probability with sufficient photon energy. A relatively high CBZ removal yield (of about 87%) was obtained for an initial pollutant concentration of 2 mg/L and an irradiation time of 150 min. A total organic carbon (TOC) reduction of about 74% was observed confirming the mineralization of the parent compound under UV light conditions. As expected, it was observed that the effect of TiO2 concentration on the degradation kinetics was significant confirming the positive influence of the increased number of TiO2 active sites on the process. Finally, the Langmuir-Hinshelwood (L-H) model was successfully used to fit the experimental results and the L-H model constants were also calculated.

18 citations

Journal Article
TL;DR: In this paper, the photocatalytic degradation of a chlorinated phenol in aqueous solution using TiO2 as a catalyst was investigated and the results showed that, under optimum degradation conditions, an irradiation time of 90 min was sufficient to completely remove the 2,4,6-trichlorophenol.
Abstract: In recent years the occurrence of chlorophenols in the aquatic environment has raised an increasing interest because of their high toxicity and low biodegradability As a result, is an increasing interest in the development of efficient techniques for their removal or inactivation Advanced oxidation processes have appeared as promising technologies for the treatment of wastewaters or effluents containing refractory organic pollutants Among such techniques, semiconductor photo catalysis is nowadays recognised as an effective strategy for the removal a high number of organic or inorganic water pollutants This paper deals with the photocatalytic degradation of a chlorinated phenol in aqueous solution using TiO2 as catalyst For this study, 2,4,6-trichlorophenol (2,4,6-TCP) was selected as model molecule The effects of some fundamental operating parameters in heterogeneous photocatalysis such as the initial pollutant concentration, catalyst load and the intensity of UV light were investigated in detail in order to fully characterize the photocatalytic process Results showed that, under optimum degradation conditions an irradiation time of 90 min was sufficient to completely remove the 2,4,6-TCP Under these experimental conditions, 94% of TOC reduction was achieved, confirming the higher mineralisation of reaction intermediates Tthe results obtained in this work are very promising, given the refractory nature of this compound

17 citations

Journal ArticleDOI
TL;DR: In this paper, the photocatalytic removal of 2,4-dichlorophenol in water solution was investigated at laboratory scale in a batch photoreactor using a commercial titanium dioxide as catalyst.
Abstract: Recently, environmental scientists have been focused their attention on the occurrence and the elimination of specific organic compounds in water. Among them, chlorophenols are considered to be a public health problem due to their carcinogenic properties. Thus, there is an important need to find new strategies to efficiently transform these compounds to no toxic or inactive by-products. In this work the photocatalytic removal of 2,4-dichlorophenol in water solution was investigated at laboratory scale in a batch photoreactor using a commercial titanium dioxide as catalyst. Effects of different operating parameters such as initial pollutant concentration, catalyst load and UV-light intensities on the photocatalytic elimination efficiency were evaluated in detail for future practical application purposes. Obtained data clearly showed an optimum degradation of the target compound under an initial pollutant concentration of 1.5 mg/L, a titanium dioxide concentration of 1 g/L and for UV-light intensity of 59.6 W/m2. The total organic carbon removal was also calculated in order to confirm the mineralization of 2,4-dichlorophenol. The obtained data showed a higher mineralization yield under the optimized photocatalytic reaction conditions demonstrating the performance of the photocatalytic oxidation to remove the target molecule at low concentrations from aqueous medium.

15 citations


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01 Jan 2011
TL;DR: In this article, the effects of various operating parameters on the photocatalytic degradation of phenols and dyes are presented, such as type of photocatalyst and composition, light intensity, initial substrate concentration, amount of catalyst, pH of the reaction medium, ionic components in water, solvent types, oxidizing agents/electron acceptors, mode of catalyst application, and calcinations temperature.
Abstract: The heterogeneous photocatalytic water purification process has gained wide attention due to its effectiveness in degrading and mineralizing the recalcitrant organic compounds as well as the possibility of utilizing the solar UV and visible light spectrum. This paper aims to review and summarize the recently published works in the field of photocatalytic oxidation of toxic organic compounds such as phenols and dyes, predominant in waste water effluent. In this review, the effects of various operating parameters on the photocatalytic degradation of phenols and dyes are presented. Recent findings suggested that different parameters, such as type of photocatalyst and composition, light intensity, initial substrate concentration, amount of catalyst, pH of the reaction medium, ionic components in water, solvent types, oxidizing agents/electron acceptors, mode of catalyst application, and calcinations temperature can play an important role on the photocatlytic degradation of organic compounds in water environment. Extensive research has focused on the enhancement of photocatalysis by modification of TiO2 employing metal, non-metal and ion doping. Recent advances in TiO2 photocatalysis for the degradation of various phenols and dyes are also highlighted in this review.

283 citations

Posted Content
TL;DR: EDC exposures in Europe contribute substantially to neurobehavioral deficits and disease, with a high probability of >€150 billion costs/year, and the results emphasize the advantages of controlling EDC exposure.
Abstract: Context: Epidemiological studies and animal models demonstrate that endocrine-disrupting chemicals (EDCs) contribute to cognitive deficits and neurodevelopmental disabilities. Objective: The objective was to estimate neurodevelopmental disability and associated costs that can be reasonably attributed to EDC exposure in the European Union. Design: An expert panel applied a weight-of-evidence characterization adapted from the Intergovernmental Panel on Climate Change. Exposure-response relationships and reference levels were evaluated for relevant EDCs, and biomarker data were organized from peer-reviewed studies to represent European exposure and approximate burden of disease. Cost estimation as of 2010 utilized lifetime economic productivity estimates, lifetime cost estimates for autism spectrum disorder, and annual costs for attention-deficit hyperactivity disorder. Setting, Patients and Participants, and Intervention: Cost estimation was carried out from a societal perspective, ie, including direct costs (eg, treatment costs) and indirect costs such as productivity loss. Results: The panel identified a 70–100% probability that polybrominated diphenyl ether and organophosphate exposures contribute to IQ loss in the European population. Polybrominated diphenyl ether exposures were associated with 873 000 (sensitivity analysis, 148 000 to 2.02 million) lost IQ points and 3290 (sensitivity analysis, 3290 to 8080) cases of intellectual disability, at costs of €9.59 billion (sensitivity analysis, €1.58 billion to €22.4 billion). Organophosphate exposures were associated with 13.0 million (sensitivity analysis, 4.24 million to 17.1 million) lost IQ points and 59 300 (sensitivity analysis, 16 500 to 84 400) cases of intellectual disability, at costs of €146 billion (sensitivity analysis, €46.8 billion to €194 billion). Autism spectrum disorder causation by multiple EDCs was assigned a 20–39% probability, with 316 (sensitivity analysis, 126–631) attributable cases at a cost of €199 million (sensitivity analysis, €79.7 million to €399 million). Attention-deficit hyperactivity disorder causation by multiple EDCs was assigned a 20–69% probability, with 19 300 to 31 200 attributable cases at a cost of €1.21 billion to €2.86 billion. Conclusions: EDC exposures in Europe contribute substantially to neurobehavioral deficits and disease, with a high probability of >€150 billion costs/year. These results emphasize the advantages of controlling EDC exposure.

116 citations

Journal ArticleDOI
TL;DR: 3D printed chitosan scaffolds may be used as reusable substrate for the TiO2 photocatalytic degradation of antibiotic pollutants in wastewater and shows a high photodegradation efficiency, compared to the direct AMX photolysis.

88 citations

Journal ArticleDOI
TL;DR: It is evident from this study that the BaTiO3/GO composite is promising for MB photodegradation through ·OH, which has the highest MB degradation rate after 3 h of UV vis irradiation.

87 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the sources, levels and health risks of volatile organic compounds emitted from the entire furniture manufacturing process in workshops and established a probabilistic health assessment model to estimate the health risks caused by VOCs (volatile organic compounds) based on the inhalation risk model and the Monte Carlo method.

72 citations