title: Immobilized laccase on oxygen functionalized nanobiochars through mineral acids treatment for removal of carbamazepine.
abstract: Biocatalytic treatment with oxidoreductase enzymes, especially laccases are an environmentally benign method for biodegradation of pharmaceutical compounds, such as carbamazepine to less harmful compounds. However, enzymes are required to be immobilized on supports to be reusable and maintain their activity. Functionalization of support prior to immobilization of enzyme is highly important because of biomolecule-support interface on enzyme activity and stability. In this work, the effect of oxidation of nanobiochar, a carbonaceous material produced by biomass pyrolysis, using HCl, H2SO4, HNO3and their mixtures on immobilization of laccase has been studied. Scanning electron microscopy indicated that the structure of nanobiochars remained intact after oxidation and Fourier transform infrared spectroscopy confirmed the formation of carboxylic groups because of acid treatment. Titration measurements showed that the sample treated with H2SO4/HNO3(50:50, v/v) had the highest number of carboxylic groups (4.7mmol/g) and consequently the highest efficiency for laccase immobilization. Additionally, it was observed that the storage, pH and thermal stability of immobilized laccase on functionalized nanobiochar was improved compared to free laccase showing its potential for continuous applications. The reusability tests towards oxidation of 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) showed that the immobilized laccase preserved 70% of the initial activity after 3cycles. Finally, using immobilized laccase for degradation of carbamazepine exhibited 83% and 86% removal in spiked water and secondary effluent, respectively.
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
authors.forename: Mitra
authors.initials: M
authors.lastname: Naghdi
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Taheran
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec G1K 9A9, Canada. Electronic address: satinder.brar@ete.inrs.ca.
authors.forename: Satinder K
authors.initials: SK
authors.lastname: Brar
authors.affiliation: Biorefining and Remediation Laboratory, Department of Process Engineering and Applied Science, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3J 1Z1, Canada.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Kermanshahi-Pour
authors.affiliation: CO(2) Solutions Inc., 2300, Rue Jean-Perrin, Québec, Québec G2C 1T9, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Verma
authors.affiliation: Department of Civil Engineering, University of Nebraska-Lincoln, N104 SEC PO Box 886105, Lincoln, NE 68588-6105, US.
authors.forename: R Y
authors.initials: RY
authors.lastname: Surampalli
keywords: Acid; Enzyme and secondary effluent; Functionalization; Immobilization; Nanobiochar; Oxidation