Macrolide antibiotics removal using a circulating TiO2-coated paper photoreactor: parametric study and hydrodynamic flow characterization

International audienceThe present work investigates the photocatalytic degradation efficiency of biorecalcitrant macrolide antibiotics in a circulating tubular photoreactor. As target pollutants, spiramycin (SPM) and tylosin (TYL) were considered in this study. The photoreactor leads to the use of an immobilized titanium dioxide on non-woven paper under artificial UV-lamp irradiation. Maximum removal efficiency was achieved at the optimum conditions of natural pH, low pollutant concentration and a 0.35 L min(-1) flow rate. A Langmuir-Hinshelwood model was used to fit experimental results and the model constants were determined. Moreover, the total organic carbon analysis reveals that SPM and TYL mineralization is not complete. In addition, the study of the residence time distribution allowed us to investigate the flow regime of the reactor. Electrical energy consumption for photocatalytic degradation of macrolides using circulating TiO2-coated paper photoreactor was lower compared with some reported photoreactors used for the elimination of pharmaceutic compounds. A repetitive reuse of the immobilized catalyst was also studied in order to check its photoactivity performanc

Bioremediation: an overview on current practices, advances, and new perspectives in environmental pollution treatment

[Excerpt] Environmental pollution generated the need to search for new environmentally friendly, low-cost, and more efficient environmental clean-up techniques for its removal or reduction. Bioremediation, a branch of environmental biotechnology, is nowadays considered as one of the most promising alternatives. This technology uses the amazing ability of microorganisms or plants to accumulate, detoxify, degrade, or remove environmental contaminants. Bioremediation provides the transformation and/or even removal of organic and inorganic pollutants, even when they are present at low concentration. Continuous efforts are still made to understand the mechanisms by which microorganisms and plants remove or transform environmental pollutants. Thus, the purpose of this special issue was to explore different visions on bioremediation, while addressing recent advances and new ideas in the perspective of efficient process scale-up in view of application at larger scales. Authors’ contributions cover various topics with a range of papers including original research and review articles spanning studies in remediation of different environments which outline new findings in the biotechnology field. This special issue contains five papers including one review article and four original research articles. A brief description of these five manuscripts is detailed below. [...]We would like to extend our gratitude to all the authors who submitted their work for consideration in our special issue and to reviewers for their critical feedback. Contributions of Raluca Maria Hlihor and Maria Gavrilescu to this special issue were supported by a grant of the Romanian National Authority for Scientific Research,CNCS-UEFISCDI (Project no. PN-III-P4-ID-PCE-2016-0683, Contract no. 65/2017). Teresa Tavares’ contribution is supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the research project PTDC/AAG-TEC/5269/2014, the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of NORTE 2020 (Programa Operacional Regional do Norte).info:eu-repo/semantics/publishedVersio

Excellent ambient oxidation and mineralization of an emerging water pollutant using Pd-doped TiO2_{{2}} photocatalyst and UV-A irradiation

International audienceTiO2_Pd prepared by the incipient wet impregnation (IWI) method was successfully used as a photocatalyst for the degradation of an emerging water pollutant, clofibric acid (CA). It exhibits an improved photoactivity in comparison with different commercial titania in the degradation of CA (25 ppm). The irradiation intensity, photocatalyst dose, CA concentration and influence of water quality and of some salts in the reaction medium were systematically examined to understand their effects on the process efficiency. A total pollutant decomposition and a high mineralization yield (78%) were achieved in 50 and 190 min, respectively, in the optimal conditions, which is very promising for practical applications

Detection and survival of Yersinia enterocolitica in goat cheese produced in San Luis, Argentina

Detection limits and the survival of Yersinia enterocolitica in goat cheese were determined by culture and by nested polymerase chain reaction (PCR). Thirty goat cheese samples inoculated with 104 to 101 cfu/g Y. enterocolitica O:9 or O:3 strains were enriched for 0, 3 and 18h in trypticase soy broth (TSB), modified Rappaport broth and a formulated in our laboratory broth (FLB). The lowest detection limits were 1×103cfu/g by culture on Mac Conkey agar after 3h TSB and FLB enrichments, and 1×102cfu/g by nested PCR at 3h from all enrichment broths. Y. enterocolitica survival was studied in 20 goat cheese samples contaminated at levels of 1×106cfu/g and stored at 4° and 22C for 120 days. Y. enterocolitica was detected during 7 and 30 days at 22C and 4C, respectively. Total and fecal coliforms were recovered from microflora of goat cheese, but indigenous Y. enterocolitica was not detected.Fil: Lazarte Otero, Valeria Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Favier, Gabriela Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Velázquez, Lidia. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Escudero, María Esther. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; ArgentinaFil: Stefanini de Guzman, Ana Maria Teresa Valentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Área Microbiología; Argentin

Etude cinétique et stoechiométrique de la croissance de Rhodospirillum rubrum en photobioréacteur

CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

Adsorption des perturbateurs endocriniens lors de la potabilisation (développement d une méthodologie d obtention des paramètres d équilibre et cinétiques)

Les perturbateurs endocriniens sont des micropolluants qui ont révélé un potentiel estrogénique à des teneurs retrouvées dans les eaux, allant du g.L-1 au ng.L-1. L adsorption sur charbon actif est le procédé de traitement spécifiquement conçu pour l élimination de la pollution organique. L évaluation des performances de ce procédé dans des conditions réelles (faibles concentrations de produit, présence de matière organique) nécessite des essais lourds et onéreux, notamment vis-à-vis de l analyse. Une méthode d analyse par SPE-UPLC-MS/MS a été mise en place et validée. Un traitement statistique poussé a été effectué pour déterminer l impact de l hétéroscédasticité de la variance du signal du spectromètre de masse sur la précision des résultats. Une méthodologie a été développée devant permettre d obtenir ces informations en effectuant des essais d adsorption à haute concentration puis en extrapolant les performances d adsorption à basse concentration à l aide de modèles. Les essais ont été effectués sur le bisphénol A et l éthinylestradiol et deux charbons actifs en poudre, à haute et, pour la validation, à basse concentration. Différents modèles ont été testés afin d évaluer leur capacité d extrapolation. Les résultats ont montré que l approche de l IAST, pour l adsorption compétitive, et le modèle HSDM, pour la cinétique, calibrés à haute concentration sont capables d extrapoler les équilibres et cinétiques des composés étudiés à basse concentration.Endocrine disrupting compounds are micropollutants that have shown estrogenic activity at environmentally relevant concentration levels, from g.L-1 to ng.L-1. Activated carbon adsorption is specifically designed to remove organic pollution. The assessment of the process efficiency in real conditions (low concentration level, simultaneous adsorption of organic matter) requires stringent and costly experimentations, in particular due to the analysis. An analytical method involving SPE-UPLC-MS/MS was optimized and validated. Experimental data has been analysed and processed using an advanced statistical treatment in order to assess the influence of the heteroskedasticity of the signal s variance on the precision of the results. A methodology was developed for the determination of the adsorption capabilities based on high concentration adsorption experiments and downward extrapolation of the adsorption performance at low concentration level using modelling. Bisphenol A and ethynylestradiol, and two powdered activated carbons were used for experiments at high concentration level and, for validation purpose, at low concentration level. Several models have been tested in order to determine their extrapolation capabilities. Results have shown that the IAST model, for competitive adsorption, and the HSDM theory, for kinetics, fitted at high concentration level are capable of downward extrapolation of adsorption equilibriums and kinetics of both target compounds at low concentration level.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Testing of the new streptomyces strains for production of phenoloxidases

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Asymmetric cellulose acetate membranes used in separation applications

This work focused on the use of cellulose acetate polymer for the preparation of porous asymmetric membranes using a phase inversion process. These membranes were characterised by scanning electron microscopy, a bubble-point method and sorption measurements. The preparation method used induced membrane anisotropy. The capacity of the membranes in the removal of electrolyte (NaCl) from aqueous solution was investigated. A good retention of 58.6% and a high flux rate of 8.9 × 10–4 m/s using NaCl solution of 200 mg/L concentration were obtained by cellulose acetate membranes prepared with water as non-solvent. The results showed that the membrane performance was affected by the membrane structure, which was determined by the conditions of membrane preparation

Screening of soil bacteria as potential agents for drugs biodegradation: a case study with clofibric acid

International audienceBACKGROUND Clofibric acid (CLF), the main pharmacologically active metabolite of blood lipid regulating pharmaceutical clofibrat, etofibrat, etofyllinclofibrat is one of the most widely reported drugs found in water. It is hardly or not degraded by the conventional technology used in wastewater treatment plants. RESULTS Sixteen new filamentous bacteria belonging to genus Streptomyces spp. isolated from different Romanian soil samples and three strains from a collection of microorganisms (MIUG) were morphologically characterized, tested based on their resistance against clofibric acid toxicity and then investigated as bioremediation agents. Only five Streptomyces spp. isolates coded MIUG 4.88, MIUG 4.89, LP1, LP2, SNA, showed high CLF tolerance at most of the concentrations tested (0.2, 0.5, 1, 5, 8 mg L−1). CONCLUSION The data obtained showed that only the strain Streptomyces MIUG 4.89 presents promising potential for clofibric acid biodegradation, with an elimination yield of 35%, which was not reported for this class of bacteria to date. However, further research is needed for optimization of the CLF biodegradation conditions to enhance its bioremediation yield especially in polluted aquatic systems. © 2016 Society of Chemical Industr

Optimization of Different Key Culture Conditions for Enhanced Biodegradation of a Refractory Emerging Pollutant by a Bacterial Isolate Through a Statistical Approach

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