Decolorization of azo dye methyl red by suspended and co-immobilized bacterial cells with mediators anthraquinone-2,6-disulfonate and Fe3O4 nanoparticles

Abstract

a b s t r a c tIn this study, the decolorization and degradation of methyl red (MR) by suspended and immobilized cells of Aeromonas jandaei strain SCS5 under anaerobic and aerobic conditions have been investigated. The complete decolorization of MR at a concentration of 100 mg L À1 by A. jandaei strain SCS5 was obtained within 6 h for both anaerobic and aerobic suspended cultures, where the decolorization rate was faster in acidic conditions than basic conditions. The decolorization efficiency under 6 h increased with increasing cell mass of inoculation and decreased with increasing initial dye concentrations. Immobilized cells of A. jandaei strain SCS5 could decolorize MR, and the decolorization rate was significantly enhanced by cells immobilized with mediators such as anthraquinone-2,6-disulphonate and magnetic Fe 3 O 4 nanoparticles compared to immobilized cells only. Moreover, the immobilized bacterial beads with mediators retained high decolorization activity up to more than 10 repeating cycles. UVevisible spectra (200 e800 nm) and gas chromatography-mass spectrometry analysis demonstrated that MR was degraded by A. jandaei strain SCS5 through reductive cleavage of azo bond. MR degradation products showed less phytotoxicity against Triticum aestivum and Phaseolus mungo compared to untreated MR. This study has demonstrated that A. jandaei strain SCS5 could be a promising microbiological agent for the removal of azo dyes from the environment.

Bio-removal of Azo Dyes: A Review

“…The formation of highly stable AgNPs was visually confirmed by the appearance of yellow color and further verified by the existence of surface plasmon resonance (SPR) peak around 425 nm. Sharma et al (2016) have studied decolorization and degradation of Methyl Red by suspended and immobilized cells of Aeromonas jandaei strain SCS5 under anaerobic and aerobic conditions. The complete decolorization of Methyl Red at a concentration of 100 mg l -1 by A. jandaei strain SCS5 was recorded within 6 h for both anaerobic and aerobic suspended cultures, but the decolorization rate was faster in acidic than basic P.K.…”

Methyl Red Decolorization Efficiency of a Korea Strain of Aspergillus sp. Immobilized into Different Polymeric Matrices

“…Previous studies have reported decolorization of azo dye methyl red (MR) using microbial strain. For example, a recent study has reported decolorization of azo dye MR using immobilized bacterial cells of Aeromonas jandaei (Sharma et al, 2016). Zhao et al, have also reported the biodegradation of MR by Bacillus sp.…”

Aplicação de aeração intermitente para a degradação de corante azo por consórcio microbiano obtido de florestas tropicais

“…Ademais, algumas tecnologias envolvidas no tratamento físico-químico destes efluentes, e.g. membranas e meios filtrantes, possuem alto custo (Dos Santos et al, 2007;Sharma et al, 2016). A degradação biológica de azo-corantes tem sido estudada por vários autores pela premissa de oferecer uma solução mais sustentável do ponto de vista econômico e de produção de resíduos, além do seu potencial de reduzir ou até mesmo eliminar a toxicidade desses efluentes.…”

“…As aminas aromáticas e outros intermediários gerados no processo de descoloração redutiva são recalcitrantes ao tratamento anaeróbio, de modo que muitos autores optam por um pós-tratamento aeróbio para remoção destes compostos (Amaral et al, 2014;Amorim et al, 2013;Braúna et al, 2009;Gavazza et al, 2015;Imran et al, 2016;Sharma et al, 2016;Talarposhti et al, 2001). A aplicação de aeração intermitente para a remoção de cor, que será testada neste estudo, é uma alternativa aos processos convencionais anaeróbio-aeróbios e visa à descoloração e biodegradação de metabólitos no mesmo compartimento reacional.…”

“…No processo denominado descoloração redutiva, o azo é reduzido diretamente pela ação de enzimas biológicas, ou indiretamente, na presença de mediadores de óxido-redução (mediador redox, MR) (Singh et al, 2015). Apesar disso, a degradação desses corantes é incompleta nessas condições, tornando necessária a utilização de um pós-tratamento aeróbio para a remoção dos intermediários tóxicos (Amaral et al, 2014;Amorim et al, 2013;Braúna et al, 2009;Gavazza et al, 2015;Imran et al, 2016;Sharma et al, 2016;Talarposhti et al, 2001).…”