Co-immobilized spore laccase/TiO 2 nanoparticles in the alginate beads enhance dye removal by two-step decolorization
- PDF / 1,849,713 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 8 Downloads / 195 Views
RESEARCH ARTICLE
Co-immobilized spore laccase/TiO2 nanoparticles in the alginate beads enhance dye removal by two-step decolorization Mojtaba Khakshoor 1 & Ali Makhdoumi 1
&
Ahmad Asoodeh 2 & Mohammad Reza Hosseindokht 2
Received: 30 April 2020 / Accepted: 16 September 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Combinatorial application of different dye removal methods with specific features can lead to a novel and robust decolorizing system. In this study the bacterial spore laccase and TiO2 nanoparticles were co-entrapped to enhance dye degradation. The optimum entrapment conditions were achieved in the presence of alginate 2% (w/v) and Ca2+ (0.2M), Cu2+ (0.05M) and Zn2+ (0.25M) as matric polymer and counterions, respectively. Immobilized laccase showed a wide range of pH and temperature stability in comparison to the free spores. The entrapped degradation systems include single laccase, single TiO2, laccase + TiO2 (one-step remediation), TiO2/laccase (two-step remediation), and laccase/TiO2 (two-step remediation) that result to the 22%, 26% 45.6%, 47.6%, and 69.3% indigo carmine decolorization in 60 min. In the kinetic studies, the half-life of indigo carmine (25 mg/l) in the remediation processes containing laccase, TiO2, laccase + TiO2, TiO2/laccase, and laccase/TiO2 was calculated as 173, 138, 161, 115, and 57 min, respectively. The degradation products by co-entrapped system were not toxic against Sorghum vulgare. The results showed two-step decolorization by co-entrapped spore laccase and TiO2 nanoparticles, including the pretreatment of dye by laccase, and then, treatment by TiO2 has potential for degradation of indigo carmine. Keywords Entrapment . Laccase . Photocatalysis . Synthetic dye
Introduction Synthetic dyes are extensively used in industries (7 × 105 t per year) and accordingly discharged into the surrounding environments (Chauhan et al. 2017). The released dye-containing wastewaters have several human and environmental health hazards and are toxic, mutagenic, carcinogenic, and have negative aesthetic impacts (Lellis et al. 2019). To protect the ecosystem, these wastewaters must be treated to reduce their dyestuff pollutants. Several physicochemical (reverse osmosis,
Responsible editor: Sami Rtimi Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-020-10901-1) contains supplementary material, which is available to authorized users. * Ali Makhdoumi [email protected] 1
Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
2
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
flocculation, ion exchange, adsorption, filtration, oxidation, ozonation, Fenton process, and photocatalysis) and biological (biodegradation) approaches were developed to manage this environmental dilemma (Singh and Arora 2011). Bio-based remediation processes are known as eco-friendly, but their efficiencies are relatively low. On the other hand, physicochemica
Data Loading...
