Anthraquinone Dye Reactive Blue 19 Research Articles

Optimization of Anthraquinone Dye Wastewater Treatment using Ozone in the Presence of Persulfate Ion in a Semi-batch Reactor

The degradation of anthraquinone dye Reactive Blue 19 by using O3 and O3 / S2O8 2- in the advanced oxidation processes is studied to investigate the performance of these two systems. The response surface method with a Box-behnken Design was successfully applied to identify the relationship between operating variables such as initial concentration, S2O8 2- dosage and contact time in order to determine the optimum operating condition. The quadratic model for the percentage COD removal (response) proved to be significant for the degradation of the dye. The COD removal efficiency under Box-behnken Design and experimental test were found to be 96.2% and 83.9% under the optimum conditions. Furthermore, the result obtained showed that the O3 / S2O8 2- system is more effective than the O3 only in treating the Reactive Blue 19.

Efficient Degradation of Zearalenone by Dye-Decolorizing Peroxidase from Streptomyces thermocarboxydus Combining Catalytic Properties of Manganese Peroxidase and Laccase.

Ligninolytic enzymes, including laccase, manganese peroxidase, and dye-decolorizing peroxidase (DyP), have attracted much attention in the degradation of mycotoxins. Among these enzymes, the possible degradation pathway of mycotoxins catalyzed by DyP is not yet clear. Herein, a DyP-encoding gene, StDyP, from Streptomyces thermocarboxydus 41291 was identified, cloned, and expressed in Escherichia coli BL21/pG-Tf2. The recombinant StDyP was capable of catalyzing the oxidation of the peroxidase substrate 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), phenolic lignin compounds 2,6-dimethylphenol, and guaiacol, non-phenolic lignin compound veratryl alcohol, Mn2+, as well as anthraquinone dye reactive blue 19. Moreover, StDyP was able to slightly degrade zearalenone (ZEN). Most importantly, we found that StDyP combined the catalytic properties of manganese peroxidase and laccase, and could significantly accelerate the enzymatic degradation of ZEN in the presence of their corresponding substrates Mn2+ and 1-hydroxybenzotriazole. Furthermore, the biological toxicities of the main degradation products 15-OH-ZEN and 13-OH-ZEN-quinone might be remarkably removed. These findings suggested that DyP might be a promising candidate for the efficient degradation of mycotoxins in food and feed.

Enzymatic Degradation of Multiple Major Mycotoxins by Dye-Decolorizing Peroxidase from Bacillus subtilis.

The co-occurrence of multiple mycotoxins, including aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON), widely exists in cereal-based animal feed and food. At present, most reported mycotoxins degrading enzymes target only a certain type of mycotoxins. Therefore, it is of great significance for mining enzymes involved in the simultaneous degradation of different types of mycotoxins. In this study, a dye-decolorizing peroxidase-encoding gene BsDyP from Bacillus subtilis SCK6 was cloned and expressed in Escherichia coli BL21/pG-Tf2. The purified recombinant BsDyP was capable of oxidizing various substrates, including lignin phenolic model compounds 2,6-dimethylphenol and guaiacol, the substrate 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), anthraquinone dye reactive blue 19 and azo dye reactive black 5, as well as Mn2+. In addition, BsDyP could efficiently degrade different types of mycotoxins, including AFB1, ZEN and DON, in presence of Mn2+. More important, the toxicities of their corresponding enzymatic degradation products AFB1-diol, 15-OH-ZEN and C15H18O8 were significantly lower than AFB1, ZEN and DON. In summary, these results proved that BsDyP was a promising candidate for the simultaneous degradation of multiple mycotoxins in animal feed and food.

Oxidation characteristics and degradation potential of a dye-decolorizing peroxidase from Bacillus amyloliquefaciens for crystal violet dye

In the current work, studies were conducted for understanding oxidation characteristics and biodegradation potential of a dye-decolorizing peroxidases from Bacillus amyloliquefaciens (BaDyP) for triphenylmethane dye crystal violet (CV). Recombinant BaDyP from Bacillus amyloliquefaciens MN-13 exhibits a broad substrates profile. It can oxidize ABTS, veratryl alcohol, Mn2+, azo dye reactive black 5, anthraquinone dye reactive blue 19, but cannot oxidize guaiacol. The maximum BaDyP activity against ABTS was obtained at 30 ℃ and pH 4.0. When CV was treated by BaDyP for 72 h, the degradation percentage of 63.0 % was observed. UV–vis spectra and HPLC/MS analysis indicated that CV degradation occurred via N-demethylation and cleavage of conjugated chromophore structure. The identified degradation products included stepwise N-demethylated intermediates during the N-demethylation of CV and, 4-(N-methylamino)-4′-(N’-methylamino) benzophenone and 4-(N-methylamino)-4′-amino benzophenone after cleavage of conjugated chromophore structure. Based on these data, a hypothetic mechanism of CV degradation mediated by BaDyP was proposed in this study. Finally, it is worth to be noted that BaDyP possessed high decolorization efficiency (72.3 % removal ADMI) for actual dye effluent. These results demonstrated that BaDyP might be used as an efficient biocatalyst for the enzymatic pretreatment of dyes in wastewater.

Degradation of anthraquinone dye reactive blue 19 using persulfate activated with Fe/Mn modified biochar: Radical/non-radical mechanisms and fixed-bed reactor study

In this study, a heterogeneous activator was prepared via the Fe/Mn modification of sludge-derived biochar (Fe/MnBC) to achieve high-efficiency activation of persulfate (PS) for reactive blue 19 (RB19) degradation. The morphologies and chemical states of Fe/MnBC were examined by various characterizations. A comprehensive assessment was conducted to reveal the effects of biochar preparation conditions and system reaction conditions. According to the results of scavenger quenching experiments and electron paramagnetic resonance (EPR) testing, the mechanisms of Fe/MnBC combined PS system on RB19 degradation were proposed, including radical and non-radical mechanisms. The formation and involvement of sulfate radical (SO4·−), hydroxyl radical (OH·), and singlet oxygen (1O2) were proved in this system, and Fe(IV)/Mn(VII) was also speculated to participate in the non-radical degradation process. These findings give a new insight into the mechanisms of PS activated by metal-biochar composite. Besides, fixed-bed reactor (FBR) experiments indicated that the Fe/MnBC has considerable PS activation potential for dyes removal. The degradation process was further modeled by the central composite design (CCD-RSM) and artificial neural networks (ANN) methods. The statistical metrics and prediction indicated that the prediction results of ANN model were better than CCD-RSM model, and the ANN model could perfectly predict the reaction process of Fe/MnBC FBR for engineering applications.

A novel strategy for enhancing anaerobic biodegradation of an anthraquinone dye reactive blue 19 with resuscitation-promoting factors

Anaerobic process has been widely applied as a cost-effective method for textile wastewater treatment. However, many bacteria exhibit low metabolic activity in unfavorable conditions due to the entry into a viable but non-culturable (VBNC) state. Thus, in this study, a novel method of using resuscitation-promoting factors (Rpfs), which has been proven to resuscitate and stimulate the growth of VBNC bacteria, is explored to enhance the degradation of the anthraquinone dye reactive blue 19 (RB19) in the anaerobic process. The results show that Rpfs could efficiently prompt RB19 decolorization. Compared to the conventional anaerobic condition, RB19 decolorization efficiency was increased by more than 20% with the Rpf addition. UV–visible spectral and gas chromatograph-mass spectrometry analysis indicate that the aromatic amines structures of RB19 was cleaved. More importantly, the Rpf addition appeared to stimulate and/or enrich some dye-degrading species of the family Peptostreptococcaceae, thus leading to a higher RB19 decolorization efficiency.

Effective decolorization of anthraquinone dye reactive blue 19 using immobilized Bacillus sp. JF4 isolated by resuscitation-promoting factor strategy.

Given the highly complex recalcitrant nature of synthetic dyes, biological treatment of textile wastewater using efficient bacterial species is still considered as an environmentally friendly manner. In this study, a reactive blue 19 (RB19)-degrading strain, Bacillus sp. JF4, which was isolated by resuscitation-promoting factor (Rpf) strategy, was immobilized into polyvinyl alcohol-calcium alginate-activated carbon beads (JF4-immobilized beads) for RB19 decolorization. Results suggest that the JF4-immobilized beads, which were capable of simultaneous adsorption and biodegradation, showed a high decolorization activity, while they exhibited better tolerability towards high RB19 concentrations. The JF4-immobilized beads could almost completely decolorize 100 mg/L RB19 within 10 d, while only 92.1% was decolorized by free bacteria within 12 d. Further investigation on the equilibrium and kinetics of the adsorption process suggests that the pseudo-second-order model best fit the adsorption kinetics data, and the Freundlich isotherm was the most suitable for the description of the equilibrium data. Notably, the repeated batch cycles indicated that complete decolorization of 100 mg/L RB19 by JF4-immobilized beads can be maintained for at least three cycles without much reduction in efficiency. These findings suggest that immobilizing Rpf-resuscitated strain into beads was an effective strategy for textile wastewater treatment.

Tea Residue Boosts Dye Decolorization and Induces the Evolution of Bacterial Community

Considerable researches on removal of azo dyes have been reported in recent years, but few researchers have documented adsorption and/or transformation of anthraquinone dyes by physical, chemical, or biological treatment methods due to their fused aromatic structures. In this study, tea residue was found to have significant enhancement effect on the decolorization of anthraquinone dye reactive blue 19. This effect worked on different dye decolorizing bacterial florae and the natural bacterial flora from surface water and exhibited universal feature. Six single bacterial strains were isolated from bacterial flora DDMY2. Unexpectedly, all of them had poor decolorization capacity. High-throughput sequencing results revealed the community evolution of bacterial flora DDMY2 cultured with tea residue after 6 months and 12 months. It was found that the community structure changed dramatically because the influence of tea residue and the dominant functional genera, such as unclassified_o_Pseudomonadales, Stenotrophomonas, Bordetella, and Brevibacillus, was significantly enriched. Meanwhile, the evolved community structure could keep stable for a long time, resulting in the decolorization effect stabilized for a long time. This study provides the tea residue as the bioactivator that can be applied to boost the decolorization of dyes by various potential bacterial florae. It also enlarges our knowledge of making full use of biowaste in biological wastewater treatment.

Effectual bio-decolourization of anthraquinone dye reactive blue-19 containing wastewater by Bacillus cohnii LAP217: process optimization

The Colored wastewaters produced from textile industries are enriched with toxic reactive dyes that cause serious biotic risk and ecological disturbances. The present study aims to decolourize an anthraquinone reactive blue-19 dye from aqueous solution by Bacillus cohnii LAP217. The selection of influential process parameters and optimization of process condition is performed using two-point factorial analysis and response surface method, respectively. The results reveal that the decolourization of dye is positively influenced by supplementation of di-sodium hydrogen phosphate (coefficient estimate: 7.4). The bacterium has exhibited 87.3 ± 0.4% decolourization of initial dye concentration 50 mg/L during the model validation through confirmatory experiment analysis, which has satisfactory correlation with model predicted response. However, the initial chromate concentration >50 mg/L in the medium have negative influence on performance of system by reducing the dye decolourization response below <70%, under similar process condition. Colored bacterial mass is obtained after the centrifugation of treated dye solution and a significant change in the UV-visible absorption peak is observed between raw and treated dye solution, which confirms the bio-accumulation of reactive blue-19 dye. The bacteria could exhibit significant American dyes manufactures institutes (ADMI) value reduction percentage of 79.84% during treatment of real wastewater.

Decolorization of anthraquinone dye Reactive Blue 19 by the combination of persulfate and zero-valent iron

Decolorization of anthraquinone dye Reactive Blue 19 (RB19) with sulfate radicals generated in situ from persulfate and zero-valent iron (ZVI) was investigated. The effects of initial solution pH, initial concentration of RB19, ZVI and persulfate, reaction temperature and common dissolved anions were studied. 100% color removal efficiency and 54% TOC removal efficiency were achieved in 45 min with an initial RB19 concentration of 0.1 mM under typical conditions (pH 7.0, 0.8 g L(-1) ZVI, 10 mM persulfate and 30 C). The decolorization efficiency of RB19 increased with higher iron dosage, higher initial persulfate concentration, and higher reaction temperature. It is also an acid driven process. The decolorization process followed pseudo-first order kinetics and the activation energy was 98.1 kJ mol-1. RB19 decolorization was inhibited by common dissolved anions such as CL-, NO3-, H2PO4- and HCO3- since they reacted with sulfate radicals that retarded the oxidation process. The experiment demonstrated that the combination of persulfate and ZVI was a promising technology for the decolorization of dye wastewater.

Decolorization and transformation of anthraquinone dye Reactive Blue 19 by ozonation

The decolorization and transformation of the anthraquinone dye, Reactive Blue 19 (RB‐19), by ozonation with a semi‐batch reactor were investigated. The effects of different operating parameters, such as the initial RB‐19 concentrations, ozone feed rates and initial pH, on the performance of color, dye and total organic carbon (TOC) removal were also evaluated based on their pseudo‐first‐order rate constants and removal efficiencies. The experimental results indicated that the removal of color and the dye itself was more rapid and complete than that of TOC in all the ozonation tests. However, increasing the initial RB‐19 concentration had a significant effect on decreasing the rate constant of RB‐19 reduction. In addition, increasing the ozone feed rate had positive effects on the color, dye and TOC removal, particularly on the TOC diminution. The rate constant and efficiency of color removal were highest at initial acidic pH conditions, but the dye and TOC removal were more effective at initial basic pH values, possibly due to the more powerful and non‐selective hydroxyl radical oxidation.