Meilleure présentation pour Mitra Naghdi au 32e congrès de l'Est de l'ACQE
La doctorante Mitra Naghdi, de l’équipe de la professeur Satinder K. Brar, s’est méritée le prix de la meilleure présentation lors du 32nd Eastern Canadian Symposium on Water Quality Research / 32e congrès de l'Est du Canada sur la qualité de l'eau de l'Association canadienne sur la qualité de l'eau (ACQE/CAWQ) qui se tenait à l’Université de Sherbrooke le vendredi 4 mai dernier.
La présentation de Mitra s’intitulait « Pinewood Nanobiochar: a Unique Carrier for the Immobilization of Crude Laccase by Covalent Bonding ».
Mitra Naghdi a entamé son doctorat en sciences de l’eau à l'INRS en 2015. Ses intérêts de recherche portent sur les nanotechnologies et les bioprocédés pour des applications environnementales. En 2013, elle a obtenu une maîtrise en génie chimique de l'Université de technologie d'Ispahan (Iran) où elle s'est concentrée sur l'extraction du chitosane de la paroi cellulaire fongique. Elle a également travaillé comme conférencière et ingénieure de procédés pendant quelques années. Actuellement, Mitra travaille sur le développement d'un nouveau nano-biocatalyseur comprenant du nanobiochar et des enzymes pour la dégradation de la carbamazépine, un médicament antiépileptique, présent dans l'eau et les eaux usées.
Bravo!
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Naghdi M, Taheran M, Brar SK, Ramizera AA, Verma M, Surampalli RY (2018) Pinewood Nanobiochar: a Unique Carrier for the Immobilization of Crude Laccase by Covalent Bonding. 32nd Eastern Canadian Symposium on Water Quality Research (Sherbrooke, Canada; May 4, 2018). Canadian Water Quality Association.
Abstract:
Research problem: Due to the recalcitrance of some pharmaceutically active compounds, conventional wastewater treatment is not able to remove them effectively and has raised serious global concern. Biological transformation of these contaminants using white-rot fungi and their oxidoreductase enzymes has been proposed as a low cost and environmentally friendly solution for water treatment.
Objectives: A) Covalent immobilization of laccase onto functionalized nanobiochar and investigating the efficiency of immobilization and different stability. B) Using the covalently immobilized laccase for degradation of carbamazepine in pure and secondary effluent of wastewater.
Methodology: Laccase was produced by solid-state fermentation form Tramates Versicolor. Nanobiochar with specific surface area of 47.3 m2/g and average size of 60±10 nm was produced. Oxidation of nanobiochar was performed using a mixture of mineral acids (H2SO4/HNO3 (v/v)). For covalent immobilization of laccase two cross-linkers were used at room temperature.
Results: The optimal immobilization conditions were found to be 14 mg/mL of laccase, 5 mg/mL of functionalized nanobiochar, 8.2 mM of cross-linker and 3 h of contact time. It was observed that the storage, pH and thermal stability of immobilized laccase on functionalized nanobiochar was improved compared to free laccase. Finally, immobilized laccase was used for degradation of carbamazepine exhibited 79% and 92% removal in spiked water and secondary effluent, respectively.
Conclusion: Immobilization of the enzymes on supports is a promising approach for removal of emerging contaminants from water and wastewater. They can be easily separated from the effluent and reused several times. The stability of immobilized laccase on functionalized nanobiochar was improved compared to free laccase.
Recommendations: Further investigation is required to evaluate the technical, economical and environmental aspects of different process combinations to obtain a reliable and robust strategy for degradation of micropollutants.
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Photo : Linson Lonappan, INRS
