Effect of biological mediator, 3-hydroxyanthranilic acid, in dye decolorization by Fenton processes

2015 ◽  
Vol 104 ◽  
pp. 1-7 ◽  
Author(s):  
Cássia Sidney Santana ◽  
André Aguiar
Author(s):  
Cássia Sidney Santana ◽  
Márcio Daniel Nicodemos Ramos ◽  
Camila Cristina Vieira Velloso ◽  
André Aguiar

The fungal metabolite 3-hydroxyanthranilic acid (3-HAA) was used as a redox mediator with the aim of increasing dye degradation by Fenton oxidative processes (Fe2+/H2O2, Fe3+/H2O2). Its Fe3+-reducing activity can enhance the generation of reactive oxygen species as HO● radicals. Initially, the influence of 3-HAA on decolorization kinetics of five dyes (methylene blue, chromotrope 2R, methyl orange, phenol red, and safranin T) was investigated using decolorization data from a previous work conducted by the present research group. Fe3+-containing reaction data were well fitted with first-order and mainly second-order kinetic models, whereas the BMG (Behnajady, Modirshahla and Ghanbary) model obtained optimal fit to Fe2+. Improvements in kinetic parameters (i.e., apparent rate constants and maximum oxidation capacity) were observed with the addition of 3-HAA. In another set of experiments, a decrease in apparent activation energy was observed due to introducing 3-HAA into reactions containing either Fe2+ or Fe3+ in order to decolorize phenol red at different temperatures. This indicates that the redox mediator decreases the energy barrier so as to allow reactions to occur. Thus, based on recent experiments and the reaction kinetics models evaluated herein, pro-oxidant properties have been observed for 3-HAA in Fenton processes.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 677
Author(s):  
John Onolame Unuofin

Laccase is increasingly adopted in diverse industrial and environmental applications, due to its readily accessible requirements for efficient catalytic synthesis and biotransformation of chemicals. However, it is perceived that its industrial production might incur some unfavorable overhead, which leads to expensive market products, and the corresponding negative environmental feedback, due to the use of capital-intensive and precarious chemicals. To this end, this study was designed to evaluate the performance indicators of the valorization of wheat bran by a novel Jb1b laccase and its subsequent application in waste minimization and water management, on a laboratory scale. Optimal Jb1b laccase was produced in submerged fermentation medium containing wheat bran, an agroindustrial residue, through response surface methodology (RSM) algorithm, and was applied in dye decolorization and denim bioscouring, respectively. Results showed that the resultant enzyme manifested unique biochemical properties, such as enhanced tolerance at certain physicochemical conditions, with a residual activity of at least ca. 76%. Furthermore, phenomenally high concentrations of synthetic dyes (0.2% w v−1) were decolorized over 56 h, and a 6 h mediator-supported simultaneous denim bleaching and decolorization of wash effluent was observed. The sustainability of the production and application processes were inferred from the reusability of the fermentation sludge as a potential biofertilizer, with subsequent prospects for the biostimulation and bioaugmentation of contaminated soils, whereas the decolorized water could be adopted for other uses, amongst which horticulture and forestry are typical examples. These phenomena therefore authenticate the favorable environmental feedbacks and overhead realized in this present study.


1948 ◽  
Vol 175 (1) ◽  
pp. 433-438 ◽  
Author(s):  
Herschel K. Mitchell ◽  
Joseph F. Nyc ◽  
Ray D. Owen

2021 ◽  
Vol 7 (5) ◽  
pp. 325
Author(s):  
Laura Isabel de de Eugenio ◽  
Rosa Peces-Pérez ◽  
Dolores Linde ◽  
Alicia Prieto ◽  
Jorge Barriuso ◽  
...  

A dye-decolorizing peroxidase (DyP) from Irpex lacteus was cloned and heterologously expressed as inclusion bodies in Escherichia coli. The protein was purified in one chromatographic step after its in vitro activation. It was active on ABTS, 2,6-dimethoxyphenol (DMP), and anthraquinoid and azo dyes as reported for other fungal DyPs, but it was also able to oxidize Mn2+ (as manganese peroxidases and versatile peroxidases) and veratryl alcohol (VA) (as lignin peroxidases and versatile peroxidases). This corroborated that I. lacteus DyPs are the only enzymes able to oxidize high redox potential dyes, VA and Mn+2. Phylogenetic analysis grouped this enzyme with other type D-DyPs from basidiomycetes. In addition to its interest for dye decolorization, the results of the transformation of softwood and hardwood lignosulfonates suggest a putative biological role of this enzyme in the degradation of phenolic lignin.


1972 ◽  
Vol 20 (7) ◽  
pp. 1412-1416 ◽  
Author(s):  
KAZUYUKI HIRANO ◽  
KAZUMI MORI ◽  
NOBUKO TSUBOI ◽  
SATOSHI KAWAI ◽  
TAKEO OHNO

PLoS ONE ◽  
2018 ◽  
Vol 13 (8) ◽  
pp. e0202440 ◽  
Author(s):  
Ji Zhang ◽  
Lei Sun ◽  
Hao Zhang ◽  
Shufang Wang ◽  
Xiaoyu Zhang ◽  
...  

Author(s):  
Hamid Forootanfar ◽  
Atefeh Moezzi ◽  
Marzieh Aghaie-Khozani ◽  
Yasaman Mahmoudjanlou ◽  
Alieh Ameri ◽  
...  

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