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This study investigated the synthesis of bimetallic core-shape Ni-Zn nanoparticles using Ficus exasperate leaf extract. The incorporated bimetallic Ni-Zn nanoparticles were applied for the removal of anthraquinone dye from an aqueous solution using various adsorption parameters such as adsorbate concentration, contact time, pH, temperature, and adsorbent dosage. The presence of biomolecule compounds in the aqueous extract of Ficus exasperata was confirmed by a UV-visible spectrophotometer (UV) and Fourier Transform Infrared (FT-IR) Spectrometer. A High-Resolution Transmission Electron Spectrometer revealed a spherical shape whose diameter ranged between 10.67- 30.73 nm with an average particle size of 17.42 nm. The maximum adsorption capacity for Langmuir isotherm (qm) was found to be 50.08 mg/g with R2 of 0.9994 proving the adsorption isotherm best fit for Langmuir adsorption isotherm. The Pseudo second-order kinetic model best fitted the adsorption process. The results of Gibbs free energy ( Δ G °) and enthalpy change ( Δ H °) of the adsorption of anthraquinone dye are − 81.48 J/mol/K and −26 kJ/mol indicating a spontaneous and exothermic reaction. The regeneration of the green synthesized Ni-Zn nanoparticles up to the fifth removal cycle at 48.08 mg/g revealed excellent results for the removal of anthraquinone dye from an aqueous solution. The obtained results showed that green synthesized core-shape Ni-Zn nanoparticles are excellent and eco-friendly biomaterials for the removal of anthraquinone dye from an aqueous solution. [ABSTRACT FROM AUTHOR]

Wastewater treatments in the textile industry faces many challenges, particularly due to the residues of used dyes, which are pollutants characterized by high chemical stability. One promising technology for addressing the issue is an advanced oxidation process (AOP), often utilizing Fenton's reagent as the oxidizing component. This study focuses on the degradation of the anthraquinone dye Acid Violet 109 using Fenton's reagent in a microfluidic reactor. The microreactor system consists of plunger pump units, a mixer, and a polytetrafluoroethylene (PTFE) tube. The influences of various process parameters have been analyzed, including the concentration of Fe2+, microreactor characteristics, the Fe2+/H2O2 molar ratio, and the total flow rate of the reaction mixture. The results show that treatment with Fenton's reagent is successful, with efficiencies between 82 and 99 %.

Textile waste water has a great polluting potential as it consists of dyes, emulsifiers, toxic metals, organic and inorganic compounds. Agro-based biochar is an effective adsorbent for the removal of contaminants from textile wastewater. The present study aims to synthesise biochar derived from areca nut (areca catechu L.) husk agro-waste using low-rate pyrolysis and to analyse the anthraquinone cationic Rhodamine B (RhB) and anionic Alizarine red S (AZ) dye removal efficiency. Synthesised biochar was characterized. Hydroxyl, carboxyl, acid and ester functional groups and graphite structure with distorted carbon stacks in biochar were confirmed through FTIR and XRD analysis. SEM analysis confirms the presence of non-uniform pores with crosslinked-pore-tunnels which assists the physisorption process of dye adsorption. The factorial interaction and optimum conditions were identified through response surface methodology and regression models were obtained (R2adj >95 % and R2pred>95 %). The synthesised biochar delivered an adsorption efficiency of 89 % and 87 % for RhB and AZ dye removal within 40min. The adsorption follows the pseudo first order and fit with the Langmuir isotherm for both dyes with a maximum adsorption capacity of 105.43 mg/g and 109.52 mg/g for RhB and AZ dyes. This study works to meet UN Sustainable Development Goals (SDG 6,7,12,13 and 14) and provides a sustainable solution.

Dyes are among the main environmental pollutants, due to the high amount of discharge of wastewater, lost in the dyeing process, without any further treatment. Anthraquinone dyes are stable and resistant in the aquatic system. Among the methods that have been applied to remove these dyes from wastewaters, adsorption on activated carbon has been reported as a very effective technique, and its modification with oxides and hydroxides of metals have been used to increase its surface area. In the present study, the production of activated carbon was originated by coconut shells, and a mixture of metals and metalloids, such as magnesium, silicate, lanthanum, and aluminum (AC-Mg-Si-La-Al), was used for its subsequent modification and applied to Remazol Brilliant Blue R (RBBR) removal. AC-Mg-Si-La-Al surface morphology was studied by BET, FTIR, and SEM methods. For the evaluation of AC-Mg-Si-La-Al, several parameters, such as dosage, pH, contact time, and initial RBBR concentration were studied. According to the results, in pH 5.0 ± 0.1, the dye percentage rate reached 100% by applying 0.5 g/L. Therefore, the optimal dose of 0.4 g/L and pH 5.0 ± 0.1 are selected, which leads to 99% removal of RBBR. The experimental data found to better fit to Freundlich isotherm (R2 = 0.9189) and pseudo-second-order kinetic (R2 = 0.9291) models and 4 h were the sufficient time for adsorption. According to thermodynamics, a positive value of ∆H0 (19.661 kJ/mol) suggests the endothermic nature of the process. The AC-Mg-Si-La-Al adsorbent was able to regenerate after 5 cycles of use, showing only a 17% decrease in its efficiency. Because of its effectiveness in full RBBR removal, AC-Mg-Si-La-Al could be further examined for the removal of several other dyes, even anionic or cationic. [ABSTRACT FROM AUTHOR]

Wastewater management is of considerable economic and environmental importance for the dyeing industry. Digital textile printing (DTP), which is based on sublimation transfer and does not generate wastewater, is currently being explored as an inkjet-based method of printing colorants onto fabric. It finds wide industrial applications with most poly(ethylene terephthalate) (PET) and nylon fibers. However, for additional industrial applications, it is necessary to use natural fibers, such as cotton. Therefore, to expand the applicability of DTP, it is essential to develop a novel reactive disperse dye that can interact with the fabric. In this study, we introduced a blocked isocyanate functional group into the dye to enhance binding to the fabric. The effect of sublimation transfer on fabrics as a function of temperature was compared using the newly synthesized reactive disperse dyes with different blocking groups based on pyrazole derivatives, such as pyrazole (Py), di-methylpyrazole (DMPy), and di-tert-butylpyrazole (DtBPy). Fabrics coated with the new reactive disperse dyes, including PET, nylon, and cotton, were printed at 190 °C, 200 °C, and 210 °C using thermal transfer equipment. In the case of the synthesized DHP-A dye on cotton at 210 °C, the color strength was 2.1, which was higher than that of commercial dyes and other synthesized dyes, such as DMP-A and DTP-A. The fastness values of the synthesized DHP-A were measured on cotton, and it was found that the washing and light fastness values on cotton are higher than those of commercial dyes. This study confirmed the possibility of introducing isocyanate groups into reactive disperse dyes. [ABSTRACT FROM AUTHOR]

An alternative chitosan-based adsorbent modified by impregnation with deep eutectic solvent (DES) choline-chloride:urea at a molar ratio 1:2 proved efficient removal of the anthraquinone dye Acid Blue 80 (AB80) from aqueous solutions, and offered enhanced adsorption capacity compared to the starting materials. The adsorption was mainly affected by initial AB80 concentration, adsorbent dosage, contact time, and slightly influenced by temperature (25–45 °C), and pH (3.5–10). The pseudo-second-order kinetic model fitted the experimental data, and pseudo-first order model fitted as well at the highest AB80 concentration, 250 mg/L. The experimental data agreed with the Langmuir isotherm model, with a maximum adsorption capacity of 61.64 mg/g at 35 °C. The process was exothermic above 100 mg/L of dye and spontaneous up to 200 mg/L (T

The accumulation of different kinds of synthetic dyes in the environment poses a global ecological threat. White rot fungi play an important role in dye decolorization, but there is a scope for developing improvised dye decolorization methods and analysing its mechanism. In the present study, we used free and immobilized biomass (on two solid synthetic supports) of the Trametes versicolor (CB8) strain to decolorize five of the most utilized synthetic dyes belonging to three different classes, namely triphenylmethane (Brilliant Green, Crystal Violet), azo (Congo Red, Evans Blue), and anthraquinone (Remazol Brilliant Blue R) in a wide range of initial concentration (100, 200, 300 and 400 mg·L-1). The best removal (more than 90%) was observed for three dyes (Evans Blue, Remazol Brilliant Blue R, Crystal Violet) in case of free and immobilized biomass at all concentrations whereas immobilization did not prove beneficial for elimination of Congo Red. The UV-Vis spectrum analysis proved the dye decolorization was performed by biodegradation method. Through the desorption study, the individual participation of physical sorption in the decolorization of dye was investigated. It was concluded that biochemical decolorization played a major role in dye decolorization. Further research is indicated to optimize the degradation process by immobilized CB8 strain. [ABSTRACT FROM AUTHOR]

Magnetic nanomaterials are gaining increasing attention for their catalytic properties and ease of recovery, making them promising candidates for the degradation of various organic pollutants. In this study, AlFe 2 O 4 nanoparticles were employed for the first time in photocatalytic wastewater treatment. The study focused on removing Acid Green 25 anthraquinone dye through persulfate activation under UV-Visible light. AlFe 2 O 4 nanoparticles were synthesized via sol-gel auto-combustion method and characterized by various techniques (XRD, SEM, EDX, VSM, Raman and FTIR). Moreover, statistical analysis of the experimental data confirmed the strong performance of the RSM model in accurately representing the photocatalytic process. Under optimal conditions including persulfate and catalyst concentrations of 0.3 g/L and 0.83 g/L respectively, a solution pH of 3 and 45 minutes of contact time, a 96 % dye removal rate was achieved. The remaining persulfate concentration was 60 % and fully depleted within 90 minutes, indicating efficient activation by AlFe 2 O 4 photocatalyst. The activation process effectively suppressed electron-hole recombination, enhancing the overall efficiency. Scavenger experiments further identified surface-bound radicals and photogenerated holes as the main reactive species. A degradation mechanism for AG25 dye via a photocatalytic Fenton-like process was proposed, highlighting dual synergistic catalysis in the dye degradation. Ecotoxicity assessments using Vibrio fischeri bioassay revealed a significant reduction in toxicity after treatment with AlFe 2 O 4 /PS/UV-Vis system. The stability of AlFe 2 O 4 was demonstrated over five degradation cycles. The findings open new perspectives for the use of AlFe 2 O 4 in advanced wastewater treatment technologies, positioning it as a promising material for the degradation of persistent pollutants. [Display omitted] • A novel AlFe 2 O 4 was synthetized by sol-gel autocombustion and used as photocatalyst. • Persulfate was efficiently activated by AlFe 2 O 4 for the first time. • Surface-bound radicals and holes were responsible for the degradation mechanism. • Toxicity of Acid Green 25 solution was reduced from 4.2 to 0.1 Toxic Unit. • After 5 cycles, the catalyst maintained good performance. [ABSTRACT FROM AUTHOR]

Anthraquinone dyes, which include an anthraquinone chromophore group, are the second-largest among dye classes, which is often employed in textile manufacturing. A significant number of anthraquinone dyes get into the environment, creating severe pollution since many of these dyes have intricate and stable structures. Currently, microbiological treatment of wastewater is an economically and feasibly viable solution for treating printing and dyeing wastewater, and there are growing reports of biodegradation of anthraquinone dyes. In this review, we outline the current advances in the biodegradation of anthraquinone dyes, summarizes dyes biodegradation by bacterial, fungal, and algae strains, factors influencing dyes biodegradation, current methods in enhancing dyes biodegradation, resuscitation of viable but non-culturable (VBNC) bacteria for better microbial performance, and potentials of VBNC bacteria in degrading dyes. Finally, future directions and important areas for study are given, and such efforts are anticipated to improve the anaerobic degradation process. [ABSTRACT FROM AUTHOR]

This article focuses on developing a methodology which can be used to estimate the concentration of dyestuff released from textiles during domestic laundering, so that further studies involving decolorization of the wastewater from domestic washing machine can be conducted in an attempt to develop eco-friendly domestic washing processes. Due to the complexity of the problem, an approach was adopted so that, as an initial step, synthetic red and blue reactive dye solutions were prepared as representative wastewater solutions using Reactive Red 195 and Reactive Blue 19 dyestuffs for the estimation of dye concentration. This was followed by an experimental work consisting of washing tests involving the calculation of dye concentration in the wastewater obtained from domestic washing machine as well as tergotometer as a machine simulator. For this part of the work, dyed cotton plain jersey fabric samples were used to obtain wastewater solutions. All the dye solutions and the wastewater samples were measured with VIS spectrophotometer, and the maximum absorbance values were obtained at relevant wavelengths. Although the characteristics of absorbance spectra of synthetic and wastewater solutions were very different, the maximum absorbance values of both solutions overlapped at relevant wavelengths. The concentration of the dyestuff was calculated from the absorbance values measured at 540 and 592 nm for the red and blue, respectively. The statistical analysis of the data suggested that tergotometer can be used as a domestic washing machine simulator. Moreover, the regression analysis done for the dyestuff concentration under discussion revealed that the most significant factor was the washing step (main wash or rinsing) (89.5%) followed by color (red or blue) (3.4%) and washing device (washing machine or tergotometer) (1.5%).

Wastewater management is of considerable economic and environmental importance for the dyeing industry. Digital textile printing (DTP), which is based on sublimation transfer and does not generate wastewater, is currently being explored as an inkjet-based method of printing colorants onto fabric. It finds wide industrial applications with most poly(ethylene terephthalate) (PET) and nylon fibers. However, for additional industrial applications, it is necessary to use natural fibers, such as cotton. Therefore, to expand the applicability of DTP, it is essential to develop a novel reactive disperse dye that can interact with the fabric. In this study, we introduced a blocked isocyanate functional group into the dye to enhance binding to the fabric. The effect of sublimation transfer on fabrics as a function of temperature was compared using the newly synthesized reactive disperse dyes with different blocking groups based on pyrazole derivatives, such as pyrazole (Py), di-methylpyrazole (DMPy), and di-tert-butylpyrazole (DtBPy). Fabrics coated with the new reactive disperse dyes, including PET, nylon, and cotton, were printed at 190 °C, 200 °C, and 210 °C using thermal transfer equipment. In the case of the synthesized DHP-A dye on cotton at 210 °C, the color strength was 2.1, which was higher than that of commercial dyes and other synthesized dyes, such as DMP-A and DTP-A. The fastness values of the synthesized DHP-A were measured on cotton, and it was found that the washing and light fastness values on cotton are higher than those of commercial dyes. This study confirmed the possibility of introducing isocyanate groups into reactive disperse dyes.

This study investigated the regeneration of waste activated carbon (AC) that contains anthraquinone dye, by microwave irradiation. The adsorption isotherm and adsorption kinetics were analyzed by batch adsorption experiments in which Methylene blue (MB) dye and Malachite green (MG) dye were chosen as the adsorbates. The effects of microwave heating power, heating temperature and holding time on the adsorption capacity of regenerated AC were investigated. The Brunauer– Emmett–Teller equation, scanning electron microscopy, X-ray photoelectron spectroscopy and Raman spectra were used to characterize spent waste AC and regenerated AC. The results showed that microwave heating efficiently preserved the porous structure of the regenerated AC to restore the original activation sites and adsorption capacity. The specific surface area of regenerated AC was 634.73 m2/g, the maximum adsorption capacities of MB and MG were 265.65 and 366.89 mg/g, respectively, and the C–O functional groups on the surface of AC increased significantly. The adsorption isotherm was confirmed by the Langmuir isotherm, and the adsorption process could be accurately described by the pseudo-second-order kinetic model. In addition, the power consumption of microwave regeneration was significantly lower than that of traditional regeneration methods, which represented a significant improvement in adsorption chemistry. [ABSTRACT FROM AUTHOR]

Pollution with aromatic hydrocarbon has been rising because of the extreme usage of benzene containing compounds. Most of the people, animals and plants have been exposed to aromatic hydrocarbons due to polluted water sources. The aim of the present work was to carry out an experimental study for the photocatalytic degradation of aromatic hydrocarbon containing compounds by irontitanium- pillared interlayered clays (Fe-Ti-PILCs) and copper-titanium-pillared interlayered clays (Cu-Ti-PILCs). For this purpose, a dye named disperse blue 56 (DB56) was selected for treatment experiment. Zeolite was used as a catalyst support material to prepare Fe-Ti-PILCs and Cu-Ti-PILCs. The experiments were carried out in batch method and UV-Vis spectroscopy was used for analysis. Several parameters such as contact time, H2O2 and amount of PILCs were examined to find optimized conditions. The obtained degradation rates using Cu-Ti-PILCs were better than Fe-Ti-PILCs. The obtained highest removal rates were ~97% and ~94% for Cu-Ti-PILCs and Fe-Ti-PILCs, respectively in 120 min reaction time with using 100 mg/L of dye, 1 g of Fe-Ti-PILC and Cu-Ti-PILCs and 1 mL of H2O2. [ABSTRACT FROM AUTHOR]

Treatment of textile wastewater using heterogeneous photocatalysis began in the the last decade and attracted the attention of researchers due to its versatile application. The variety of applications of TiO2 as a photocatalyst was due toits numerous positive properties, such as low operating temperature, biologically inert nature, low energy consumption, water insolubility, availability and photoactivity, low toxicity, high chemical stability, suitable flat band potential, narrow bandgap and the fact that it is environmentally benign. Heterogeneous UV-TiO2 photocatalysis is capable of removing organic pollutants from textile wastewater; this has been widely studied, with the technology also having been commercialized in many developing countries. Decolorization of anthraquinone dye Reactive Blue 19 (RB 19) by heterogeneous advanced oxidation processes TiO2/UV/H2O2, TiO2/UV/KBrO3 and TiO2/UV/(NH4)2S2O8 was studied under different conditions and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate ((NH4)2S2O8). Decolorization was very fast for all three processes, and complete dye decolorization was achieved in 10 min. The effect of various ions (Cl-, SO4 2- and HCO3 -) on RB 19 decolorization was also studied. The optimal condition for the decolorization of the dye were determined to be: TiO2 concentration 1 g·dm-3, electron acceptor concentration 30.0 mmol·dm-3, dye concentration 50.0 mg·dm-3, UV intensity 1 950 µW·cm-2, at temperature 25 ± 0.5°C. In addition, experiments were performed and compared in three different matrices. In the surface water and dyebath effluent water, the removal efficiency for RB 19 was lower than that achieved in the deionized water because of the interference of complex constituents in the surface water and effluent. LC-MS analysis was carried out and the detected intermediates were compared with the previously published data for anthraquinone dyes. [ABSTRACT FROM AUTHOR]

The co-substrate is an important ingredient in the bio-decolourization process to promote the healthy growth and basic activities of bacteria. Most widely used co-substrates in bio-decolourization process are expensive and increase the carbon and nitrogen loading in treated water. The present study aims to investigate the bacterial mediated decolourization of azo (reactive red-21 and reactive orange-16), and anthraquinone (reactive blue-19) dyes using jack-fruit seed powder as co-substrate. The study reveals (mere adsorption of dye by jack-fruit seed is ruled out through controlled experiments) that decolourization of dyes using jack-fruit seed containing medium is a bacterial mediated process, in which bacteria use dye compounds as substrate and jack-fruit-seed as co-substrate. The bacterium participated in the decolourization process in presence of jack-fruit seed is classified as Pseudomonas aeruginosa SVM16 by nucleotide sequencing and phylogenetic analyses method. The effect of process parameters on decolourization performance is investigated through response surface methodology. The result reveals that the bacteria have shown capability to decolourize initial 50 mg/L of individual dye solution of reactive red-21, reactive orange-16, and reactive blue-19 by 97.7 ± 0.3%, 98.9 ± 0.3%, and 92.6 ± 0.4%, respectively. The reduction of American dye manufactures institute index values of mixed-dye solutions (reactive red-21, and reactive orange-16) and (reactive red-21, reactive orange-16, and reactive blue-19) though bio-decolourization is achieved as ∼82.7 ± 0.4% and 76.8 ± 0.4%, respectively. The bacteria have shown high salt tolerance (∼6 g/L NaCl). The jack-fruit seed supplemented decolourization process reveals that treated water has shown lesser residual organic and colour loading compared to treated water obtained from bio-decolourization process using yeast extract or other chemicals as co-substrate. The treated aqueous solutions are analysed through ATR-FTIR, GC-MS, and 1H NMR which confirm the almost complete mineralization of dye molecules through bio-decolourization process and non-toxicity of treated water proves through positive germination test of Vigna radiata seeds. Image 1 • Jack fruit seed powder (JFS) found effective co-substrate in bio-decolourization. • Amount of JFS showed highest influence on bio-decolourization performance. • A new bacterium discovered in JFS that can utilise dye molecules as substrate to grow. • JFS is superior over yeast extract as co-substrate, second one increases residual TOC. • JFS found suitable co-substrate to bio-decolourize the real textile effluents. [ABSTRACT FROM AUTHOR]

Herein, the Ti/Co3O4 electrodes with n-type semiconductor characteristics were fabricated by a typical hydrothermal process using F− ion as dopant, and their morphology control was also performed by tailoring the hydrothermal temperature. The F− doped Ti/Co3O4 electrodes could be used as photoanode to degrade anthraquinone dye (reactive Brilliant Blue KN-R), and showed excellent photoelectrocatalytic (PEC) activity. It is proposed that the fast ions and electron transportation, high oxygen evolution potential, lower resistance, large active area, and good electrolyte infiltration are responsible for the improved PEC activity of the F− doped Ti/Co3O4 system. Nevertheless, the F− doped Ti/Co3O4 electrode with divergent flower-like structure composed of needle nanowires exhibited highest PEC activity than that of other electrodes. It is noteworthy that the presence of electrostatic anti-barrier arises from an "ohmic" contact between the metal (Ti) and the semiconductor (Co3O4) is also an important factor for the higher PEC activity of the F− doped Ti/Co3O4 electrodes. The work provides unique insight into the design of Co3O4 photoanode from a perspective of tailoring the ion doping and morphology. [ABSTRACT FROM AUTHOR]

The staining activity of twelve (12) anthraquinone dye derivatives was carried out to investigate the potential of the compounds as staining agents. The reactions of the compounds on organism cell walls were determined, and a comparison was drawn between the mechanism of action of the compounds against established mechanism of reaction of standard dyes used in biological staining. These compounds are BRAM/acetylated PPD, BRAM/PAP/p-TsCl, BRAM/Biaryl/PAP and BRAM/BzCl/PAP, BRAM/aniline, BRAM/o-toluidine, BRAM/p-toluidine, BRAM/m-toluidine, BRAM/p-anisidine, BRAM/m-anisidine, BRAM/PAP, and BRAM/p-iodoaniline. The antibacterial and antifungal activity of these compounds was determined. BRAM/BzCl/PAP exhibited higher biological activity on the bacterial types than most of the controls. From the results of the antifungal test, BRAM/m-toluidine and BRAM/acetylated PPD indicated very significant activity as much as the controls. The staining tests carried out on the compounds show that they are viable alternatives to existing dyes currently used in bacterial and fungal identification. [ABSTRACT FROM AUTHOR]

Abstract A novel heterostructure of PbO 2 tipped Co 3 O 4 nanowire arrays (NWs) is fabricated by the combination of hydrothermal synthesis and electrochemical deposition. The hydrothermal process is used to fabricate the Co 3 O 4 nanowire arrays (NWs) on the Ti sheet substrates, and subsequently the PbO 2 nanoparticles were preferentially adhered on the sharptip of Co 3 O 4 NWs using an electrochemical deposition method. It is found that the as-constructed PbO 2 /Co 3 O 4 composites exhibit large electroactive areas, low charge transfer resistance, high efficiency regarding the generation of hydroxyl radicals. The photoelectrochemical (PEC) properties of as-constructed PbO 2 /Co 3 O 4 composites were evaluated by the decolorization of dye (reactive brilliant blue KN-R) in aqueous solution. The PEC measurement indicated that as-constructed PbO 2 /Co 3 O 4 composites have higher PEC acitivity, better reproducibility and obvious photoelectric synergism, as compared with bare Co 3 O 4 NWs. The promoted PEC ability for the PbO 2 /Co 3 O 4 composites can be ascribed to the construction of heterointerface between PbO 2 and Co 3 O 4. The present work offered attractive perspectives for applications of the PbO 2 tipped Co 3 O 4 NWs in the photoanode regarding the treatment of refractory organic pollutant. Graphical abstract The PbO 2 tipped Co 3 O 4 nanowire arrays were fabricated by the combination of hydrothermal synthesis and electrochemical deposition methods. The as-constructed PbO 2 /Co 3 O 4 composites have higher PEC acitivity, better reproducibility and obvious photoelectric action, which can be ascribed to the construction of heterointerface between PbO 2 and Co 3 O 4. fx1 Highlights • The PbO 2 tipped Co 3 O 4 nanowire architectures are constructed by hydrothermal-electrochemical process. • The heterointerface between PbO 2 and Co 3 O 4 promoted the separation of induced carriers. • The significant photoelectric synergy existed in PEC process for PbO 2 tipped Co 3 O 4 nanowire arrays. [ABSTRACT FROM AUTHOR]

In this study, the removal of reactive anthraquinone dyestuff which extensively used in textile industry, was investigated by dried mass of ureolytic mixed culture (UMC) as biosorbents and optimum adsorption conditions of dye stuff were tested. UMC was grown in a nutrient enriched medium with aerated agitation. The effects of operational parameters such as initial dye concentration, biosorbent-dosage, temperature, pH and contact time were examined on the efficiency of dye removal. The highest dye removal efficiency was found at the pH 2, initial dye concentration 150 mg /L, temperature 50 0C, and contact time 20 minute. The capacity of removal (qe), and rate of adsorption were calculated as 620 mg/g; %82,67 respectively at optimal conditions. It was observed that the experimental adsorption features of anthraquinone dyestuff by ureolytic mixed culture were well fitted with the second-order adsorption kinetics and Freundlich isotherm. [ABSTRACT FROM AUTHOR]

In this study, enhancement of biodegradation and detoxification of recalcitrant anthraquinone dye was achieved by laccase from an electron beam irradiated (EBR) endophytic fungus without mediators. The partially purified laccase enzyme (160.8 ± 1.15 U mg −1 ) from 0.2 kGy irradiated endophytic fungus Phomopsis sp. catalyzed more than 85% of Remazol Brilliant Blue R (RBBR) (50 mg l −1 ) degradation into non-toxic molecules within 5 min. Laccase enzyme production increased to 1.6 fold (27.7 ± 1.06 U mg −1 ) due to electron beam radiation (0.2 kGy) of Phomopsis sp. compared to the non-irradiated fungus (17.28 ± 1.09 U mg −1 ). Laccase enzyme from electron beam irradiated fungus exhibited extreme tolerance for the metals Zn 2+ , Cu 2+ , Cr 2+ and Ca 2+ up to 10 mM concentration. The kinetic parameters V max and K m for enzymatic decolorization (0.2 kGy EBR) were estimated by Lineweaver-Burk plot and were found to be more potent than the laccase from non-irradiated fungus. The laccase enzyme retained activity in broad range of temperature (25–45 °C) and pH (4–8). The COD of the original dye was reduced to 60% after biodegradation by the irradiated fungus. The toxicity studies revealed that the degraded dye was non-toxic on plants and microbial growth. The data from LC-MS analysis clearly indicates partial degradation of dye into non-toxic molecules by laccase (0.2 kGy) following oxidation, hydroxylation, deamination and ring cleavage. [ABSTRACT FROM AUTHOR]

Abstract: This research article describes the development of a simple and sensitive approach with less runtime for the estimation of photo degradation of an anthraquinone dye drimarene red K-4BL in the presence of newly synthesized nano catalyst. Hydrothermal approach is used to synthesize cobalt hydroxystannate by using precursor salts of chloride i.e. stannic chloride, cobalt chloride and sodium hydroxide is used as a precipitating agent. Various techniques were used to analyze the product. Two major applications of synthesized nanocubes are investigating the efficiency of modified fuel and as a photocatalyst for dye degradation. Anthraquinone dye (drimarene red K-4BL) is degraded by the newly synthesized nanoparticles which is used as a catalyst in aqueous medium. In the presence of sun irradiation at different concentrations of hydrogen peroxide and catalyst, kinetics of photo catalytic degradation of dye is monitored on ultra violet visible spectrophotometer. Efficiency of modified fuel is analyzed by studying the various parameters such as flash point, fire point, pour point and cloud point, etc. at different dosage of Cobalt hydroxystannate. By changing the dosage of the catalyst, values of these parameters changed significantly.Graphical Abstract: [ABSTRACT FROM AUTHOR]

The Ti4O7 modified Ti/PbO2 electrodes have been prepared by electrodeposition, and investigated systemically using scanning electron microscope (SEM), Energy dispersive X‐ray spectroscopy (EDS), powder X‐ray diffraction (XRD), photoluminescence spectroscopy (PL), and degradation of anthraquinone dye (reactive brilliant blue KN−R: C22H16N2Na2O11S3). It is found that the Ti4O7 modified Ti/PbO2 electrodes possessed smaller PbO2 crystal grains, good porous structure, enhanced oxygen evolution over‐potential and higher electrical conductivity, as compared to that of Ti/PbO2 electrode. Additionally, the Ti4O7 modified Ti/PbO2 electrode exhibited also longer accelerated lifetime, and higher photoelectrocatalytic activity for degradation of anthraquinone dye (reactive brilliant blue KN−R) than that of Ti/PbO2 electrode. The enhancement of the decolorization efficiency and stability for Ti4O7 modified Ti/PbO2 electrodes can be ascribed to the large electrochemical active areas, the presence of photoelectric synergism, rapid separation of photogenerated carriers, inhibition of oxygen precipitation, high current efficiency for formation of hydroxyl radicals, and the weakening of internal stress in PbO2 coatings. [ABSTRACT FROM AUTHOR]

The Ti4O7 modified Ti/PbO2 electrodes have been prepared by electrodeposition, and investigated systemically using scanning electron microscope (SEM), Energy dispersive X‐ray spectroscopy (EDS), powder X‐ray diffraction (XRD), photoluminescence spectroscopy (PL), and degradation of anthraquinone dye (reactive brilliant blue KN−R: C22H16N2Na2O11S3). It is found that the Ti4O7 modified Ti/PbO2 electrodes possessed smaller PbO2 crystal grains, good porous structure, enhanced oxygen evolution over‐potential and higher electrical conductivity, as compared to that of Ti/PbO2 electrode. Additionally, the Ti4O7 modified Ti/PbO2 electrode exhibited also longer accelerated lifetime, and higher photoelectrocatalytic activity for degradation of anthraquinone dye (reactive brilliant blue KN−R) than that of Ti/PbO2 electrode. The enhancement of the decolorization efficiency and stability for Ti4O7 modified Ti/PbO2 electrodes can be ascribed to the large electrochemical active areas, the presence of photoelectric synergism, rapid separation of photogenerated carriers, inhibition of oxygen precipitation, high current efficiency for formation of hydroxyl radicals, and the weakening of internal stress in PbO2 coatings. [ABSTRACT FROM AUTHOR]

The conductive carbon black (CCB)-modified Ti/F-PbO2 electrodes were prepared by electrodeposition and characterized systemically using SEM, EDS, XRD, and PL. It is found that the embedding CCB into the PbO2 coating inhibited the growth and aggregation of the PbO2 crystal grains, caused the formation of porous structure and the preferred growth of the (101) and (301) planes of the PbO2 crystal, and enhanced the oxygen evolution overpotential and carrier density of PbO2. The degradation experiment of anthraquinone dye (reactive brilliant blue KN-R) showed that the CCB-modified Ti/F-PbO2 electrodes had higher photoelectrocatalytic activity than that of the bare Ti/F-PbO2 electrode. In addition, the accelerated life measurement demonstrated that the lifetime of the CCB-embedded Ti/F-PbO2 electrode was much longer than that of the bare Ti/F-PbO2 electrode. The improvement of decolorization efficiency and stability of the CCB-modified Ti/F-PbO2 can be attributed to the large active areas, the presence of photoelectric synergism, the inhibition of oxygen precipitation, high current efficiency for formation of hydroxyl radicals, and the weakening of internal stress in PbO2 coatings. [ABSTRACT FROM AUTHOR]

Biodegradation of a cotton‐reactive dye (C. I. Reactive Blue 4, 50 mg/L) based on anthraquinone chromophore was attempted by a newly isolated bacterial species, Staphylococcus hominis subsp. hominis DSM 20328. The maximum dye decolorization efficiency was found to be 97% in 24 h upon optimization of pH, temperature, concentrations of carbon source and dye, salt, and glucose. Fourier Transform Infrared Spectroscopy analysis and High Pressure Liquid Chromatography was used to observe changes in the dye structure caused by the biodegradation, while the pathway for degradation was suggested by Gas Chromatography–Mass Spectrometry analysis. One of the metabolites formed was revealed to be catechol. Reduction in toxicity of the dye by formation of metabolites was established with the phytotoxicity and microtoxicity studies. Thus, the isolated bacterial species has a potential application in remediation of dyes and the decolorized wastewater can be safely disposed off into agricultural fields. To our knowledge, it is for the first time that a non‐pathogenic bacterial strain of Staphylococcus species is being reported with decolorizing ability for anthraquinone chromophore‐based dye along with the detailed mechanism of dye degradation. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 203–214, 2018 [ABSTRACT FROM AUTHOR]

Exploiting the tumor microenvironment provides a new strategy for cancer treatment. In order to develop the microenvironment-selective photosensitiser, we rationally designed a proton-activatable aminated-chrysophanol derivative-compound 3 , which combines fluorescence and reactive oxygen species regulated by the tumor acidic microenvironment for the first time. Furthermore, two PET tertiary amine substituents introduced by compound 3 enhance the cellular uptake, prolong the wavelength of the absorption, and increase the phototoxicity. Not only can compound 3 distinguish the cancer cells from normal cells but also the tumor from the normal tissue by the higher fluorescence intensity in cancer cells and tissues. Additionally, lysosome destruction test proves cell necrosis in lysosomal related pathway. We believe that the proton-activatable photosensitiser modulated by tumor acidic microenvironment offers a good chance for the cancer treatment in clinic. [ABSTRACT FROM AUTHOR]

Treatment of textile wastewater containing anthraquinone dye is quite a huge challenge due to its complex aromatic structure and toxicity. Present study deals with the degradation and detoxification of anthraquinone dye reactive blue 4 using aerobic bacterial granules. Bacterial granules effectively decolorized reactive blue 4 at wide range of pH (4.0–11.0) and temperature (20–55 °C) as well as decolorized and tolerated high concentration of reactive blue 4 dye upto 1000 mg l −1 with V max 6.16 ± 0.82 mg l −1 h −1 and K m 227 ± 41 mg l −1 . Metagenomics study evaluates important role of Clostridia, Actinobacteria, and Proteobacterial members in biotransformation and tolerance of high concentrations of reactive blue 4 dye. Up-regulation of xenobiotic degradation and environmental information processing pathways during dye exposure signifies their noteworthy role in dye degradation. Biotransformation of dye was confirmed by significant decrease in the values of total suspended solids, biological and chemical oxygen demand. The metabolites formed after biotransformation was characterized by FT-IR and GC-MS analysis. The reactive blue 4 dye was found to be phytotoxic, cytotoxic and genotoxic whereas its biotransformed product were non-toxic. This study comprehensively illustrates that, bacterial aerobic granules can be used for eco-friendly remediation and detoxification of wastewater containing high organic load of anthraquinone dye. [ABSTRACT FROM AUTHOR]

Black TiO-modified Ti/PbO electrode was fabricated by the electro-codeposition method and characterized by transmission electron micrographs, scanning electron microscope, X-ray diffraction, photoluminescence, and X-ray photoelectron spectroscopy. The results indicated that the incorporation of black TiO nanoparticles facilitated the formation of porous PbO architecture, improved the oriented growth of [101] and [301] planes, and inhibited the oxygen evolution reaction. The degradation experiment of anthraquinone dye (reactive brilliant blue KN-R) indicated that black TiO embedded Ti/PbO electrode has higher photo-electrocatalytic activity than that of Ti/PbO electrode. Furthermore, the accelerated life test showed that the service life of black TiO embedded Ti/PbO electrode was much longer than that of Ti/PbO electrode. The enhancement of decolorization efficiency and stability for black TiO embedded Ti/PbO electrodes can be attributed to the formation of porous PbO architecture, the existence of photoelectric synergy, inhibition of the oxygen evolution reaction, and weakening of internal stress in PbO coatings. The black TiO embedded Ti/PbO electrode is considered as a promising anode for the treatment of organic pollutants. Graphical Abstract: The black TiO embedded Ti/PbO electrode showed significant photoelectric synergy in PEC process for degradation of anthraquinone dye aqueous solution (reactive brilliant blue KN-R) owing to introduction of black TiO. [ABSTRACT FROM AUTHOR]

White-rot fungi are efficient degraders of lignin whose extracellular enzymes have a potential to degrade organopollutants. In natural conditions these fungi enter into interactions with other organisms, which may affect their biodegradation capacity. The aim was to investigate the ability of Pleurotus ostreatus to form stable biofilms and to test the capacity of the fungus to degrade Remazol Brilliant Blue R in mixed cultures with bacteria. Bacterial counts were determined to see the behavior of the bacterium in the mixed culture with the fungus. In axenic conditions, the homogenized fungal mycelium was able to form an active biofilm which quickly degraded the dye. The addition of Pseudomonas fluorescens or Bacillus licheniformis bacteria at 10 6 CFU·mL − 1 did not affect the decolorization rate by 7-d-old fungal biofilms where the decolorization rate reached 90%. In contrast, when fragments of the fungal mycelium were used for inoculation to pre-formed biofilm of P . fluorescens , the biofilm was allowed to develop for one week's time, no decolorization of RBBR was observed and low activities of MnP and laccase were detected. The use of agar disks covered with fungal mycelium for the inoculation to pre-formed biofilm of P . fluorescens resulted in a fully developed biofilm that decolorized RBBR with similar efficiency as the pure P . ostreatus . The difference between the agar-disk- and homogenized-mycelium inoculated fungal biofilms was corroborated by the measurement of total fungal biofilm biomass that was 6-fold lower in the latter biofilm. Capability of the fungus to overcome the competition of the bacterial biofilm thus depended on the type of fungal growth centres, where intact hyphae were superior to the fragments of mycelium. A similar effect was not observed with the biofilms of B . licheniformis where the bacterial growth was less massive. The ability of P . ostreatus biofilms to resist massive bacterial stress was demonstrated. [ABSTRACT FROM AUTHOR]

Polymer dispersed ferroelectric liquid crystals (PDFLCs) have disclosed an enormous approach for use in electro-optic and display technology since ferroelectric liquid crystals (FLCs) have inherently fast switching speeds. In this work, we equipped dichroic PDFLC using dye-doped chiral SmC*liquid crystal (LC) and ultra-violet (UV) curable polymer by polymerization induced phase separation (PIPS) method. All fundamental material aspects like optical transmissions, spontaneous polarization, threshold voltage, contrast ratio and response time as a function of applied voltage, temperature, and dye concentration were examined. In the electro-optic study, 82% transmission with a threshold field value ∼0.6 V/μm was observed for PDFLC, however, 90% transmission was achieved with a threshold field ∼0.3 V/μm at the dye concentration of 0.125% (wt./wt.). As a result, present dichroic PDFLC device shows microseconds switching response, higher polarization value and superior contrast, at low dye concentration. [ABSTRACT FROM AUTHOR]

In order to study the droplet pattern and electro-optic (EO) behaviour of polymer dispersed liquid crystal (PDLC) with the addition of dye, dichroic polymer dispersed liquid crystal (DPDLC) films were prepared using a nematic liquid crystal (NLC), photo-curable polymer (NOA 65) and anthraquinone blue dichroic dye (B2), in equal ratio (1:1) of polymer and liquid crystal (LC) by polymerisation induced phase separation (PIPS) technique. Dichroic dye was taken in different concentration (wt./wt. ratio) as 0.0625%, 0.125%, 0.25%, 0.5% and 1% of the LC mixture in DPDLC films. Initially, in an open circuit when there is no proviso for external electric field (0 V), LC droplets in polymer matrix exhibited bipolar pattern, though on closing the circuit with the increase of electric field pattern of droplets starts changing, LC molecules align along the direction of applied electric field and aligned completely relatively at higher field (30 V), which illustrate vertical radial pattern. Further, results show that the DPDLC film containing 0.0625% dye concentration with consistent average droplet size ~4.30 μm, exhibits the best transmission at lower operating voltage. [ABSTRACT FROM AUTHOR]

Synthetic dye, a valuable industrial material, causes serious pollution to the aquatic environment during manufacture and usage with wastewater discharge. Reactive Blue 4 (RB4), a commercially important anthraquinone dye, was used as the target compound for an experimental investigation on the decolorizating performance of natural manganese mineral. The kinetics of RB4 removal on the surface of natural manganese mineral and its influencing factors and metabolic pathways were studied based on batch experiments. Results demonstrated that the applied natural manganese mineral exhibits an apparently oxidative capacity to transform RB4 with 88.0% ± 1.3% removal efficiency within 24 h. The removal of RB4 mainly resulted from chemical transformation rather than physical adsorption and followed a pseudo-first-order kinetic model. The RB4 degradation was impaired by coexisting metal ions (Fe2+ and Mn2+) and an organic reducer (hydroxylamine hydrochloride). The same concentration of Fe2+ and Mn2+ (0.02 mM) had similar inhibitory effects on the oxidative reactions, and hydroxylamine hydrochloride manifested even greater suppressive effects on the reactions than did Fe2+ and Mn2+. A tentative pathway of RB4 degradation by manganese mineral was proposed based on the infrared spectrum results and confirmed by liquid chromatography tandem-mass spectrometry (LC-MS) analysis of RB4 degradation products. This paper suggests that the natural manganese mineral has the potential to be an efficient material for anthraquinone dye removal from natural water or wastewater. [ABSTRACT FROM AUTHOR]

Gadolinium (Gd)-doped silver orthophosphate (Ag 3 PO 4 ) nanoparticles, with spherical morphology, were synthesized by a co-precipitation method and their photocatalytic activities were evaluated in degradation of Reactive Blue 19 (RB19), as a model organic pollutant. The synthesized Ag 3 PO 4 and Gd-doped Ag 3 PO 4 were characterized using X-ray diffraction pattern analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, diffuse reflectance UV–vis spectroscopy and photoluminescence spectroscopy. In comparison with Ag 3 PO 4 , the experimental results revealed a considerable enhancement in photocatalytic activity of Gd-doped Ag 3 PO 4 . The optimum mole fraction of Gd loading in Ag 3 PO 4 was 3%. Lower photocatalytic degradation efficiency of RB19 in the presence of oxalate anion and p-benzoquinone indicated the crucial role of photogenerated holes and superoxide anion-radicals in photocatalysis on Gd-doped Ag 3 PO 4 . The enhancement of photocatalytic activity was attributed to scavenge the photoexcited electrons, and to suppress their recombination with holes and generation of active oxygen species. A nonlinear empirical kinetic model was introduced to predict the apparent first order rate constant ( k app ) as a function of operational parameters, including initial RB19 concentration, Gd-doped Ag 3 PO 4 dosage and light intensity. Degradation byproducts were identified using gas chromatography-mass spectrometry and a probable pathway was proposed. Moreover, Gd-doped Ag 3 PO 4 samples displayed adequate reusability after three successive experiments. [ABSTRACT FROM AUTHOR]

In this study, performance of hydrolysis acidification process treating simulated dyeing wastewater containing azo and anthraquinone dyes in different stages was investigated. The decolorization ratio, COD removal ratio, BOD/COD value, and volatile fatty acids (VFAs) production were almost better in stage 1 than that in stage 2. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) confirmed the biodegradation of Reactive Black 5 (RB5) and Remazol Brilliant Blue R (RBBR) in hydrolysis acidification process. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analyses revealed that significant difference of microbial community structures existed in stage 1 and 2. The dominant species in stage 1 was related to Bacteroidetes group, while the dominant species in stage 2 was related to Bacteroidetes and Firmicutes groups. From the results, it could be speculated that different dyes' structures might have significant influence on the existence and function of different bacterial species, which might supply information for bacteria screening and acclimation in the treatment of actual dyeing wastewater. [ABSTRACT FROM AUTHOR]

In this study, a newly isolated ascomycete fungus Trichoderma lixii F21 was explored to bioremediate the polar [Alizarin Red S (ARS)] and non-polar [Quinizarine Green SS (QGSS)] anthraquinone dyes. The bioremediation of ARS and QGSS by T. lixii F21 was found to be 77.78 and 98.31 %, respectively, via biosorption and enzymatic processes within 7 days of incubation. The maximum biosorption (ARS = 33.7 % and QGSS = 74.7 %) and enzymatic biodegradation (ARS = 44.1 % and QGSS = 23.6 %) were observed at pH 4 and 27 °C in the presence of glucose and yeast extract. The laccase and catechol 1,2-dioxygenase produced by T. lixii F21 were involved in the molecular conversions of ARS and QGSS to phenolic and carboxylic acid compounds, without the formation of toxic aromatic amines. This study suggests that T. lixii F21 may be a good candidate for the bioremediation of industrial effluents contaminated with anthraquinone dyes. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the biosorption capacity of selected strains of microscopic fungi. We optimized the biosorption process and used the Freundlich isotherm for three strains: H. haematococca BwIII43, K37 and T. harzianum BsIII33 to describe the biosorption equilibrium of anthraquinone dye, Alizarin Blue Black B (ABBB) and alkali lignin (AL). In optimal conditions (1 g of mycelium biomass, pH = 7.0, 28 °C) for ABBB and AL sorption, the live biomass of H. haematococca BwIII43 was characterized by a higher sorption capacity, amounting to 247.47 and 161.00 mg g, respectively. The highest sorption properties toward anthraquinone dye ( K = 19.96 mg g) were shown for the biomass of H. haematococca K37. In the presence of alkali lignin, the highest sorption capacity and bond strength exhibited the biomass of H. haematococca BwIII43 ( K = 28.20 mg g, n = 3.46). Effective decolorization of ABBB and AL by the selected strains of microscopic fungi indicated that the biosorption process additionally enhanced the removal of color compounds from the solution. [ABSTRACT FROM AUTHOR]

Adsorption of reactive blue 19 (RB19) dye onto NiO nanoparticles was investigated at various NiO dosages, dye concentrations, solution pHs, contact times, and temperatures in a batch system. Analysis of the adsorption data indicated that the adsorption process follows the pseudo-second-order kinetics and the adsorption equilibrium data fit to Langmuir–Freundlich (Sips) isotherm better than the Freundlich and Langmuir isotherm models. Evaluation of the thermodynamic parameters (ΔG˚, ΔH˚, and ΔS˚) revealed that the adsorption process is spontaneous, endothermic, and feasible. This study suggested NiO nanoparticles as effective adsorbents for removing RB19 from polluted water. [ABSTRACT FROM AUTHOR]

A fusant strain T1, which was constructed by protoplast fusion betweenAcinetobactersp. SRL8,Escherichiasp. XBR68 andAcinetobactersp. RC10, could simultaneously decolorize three different dyes, namely reactive brilliant blue XBR, disperse orange SRL, and red base RC. Maximum decolorization of initial 30 mg L−1was achieved at pH 7.0, 35°C and 3% inoculum (v/v) under anaerobic condition during 24 h incubation. The decolorization ratio for XBR, SRL, and RC by the strain T1 could reach 91.5, 87.6, and 65.7%, respectively. Supplementation with appropriate concentration of glucose (0.2%, w/v) in the decolorization reaction system could further enhance decolorization percent. The strain T1 was highly tolerant to three different dyes up to 400 mg L−1. Biological decolorization of the three different dyes by the strain T1 was investigated in a sequential anaerobic/aerobic process. The reaction system was operated at room temperature. The results indicated that over 95% color removal was obtained in anaerobic process and 97.6% COD removal occurred in the aerobic process. [ABSTRACT FROM AUTHOR]

In present study, a hydrolysis acidification (HA) reactor was used to deal with simulated dyeing wastewater containing Reactive Black 5 (RB5) and Remazol Brilliant Blue R (RBBR) in two stages, respectively. COD and color removal rate were detected to reveal the performance of the HA reactor. Results indicated that the color removal rate of HA reactor decreased from 66.12% to 24.00%, and 69.91%–18.01% in stage 1 and stage 2 as the concentration of dyes increased, respectively. In stage 1, the COD removal rate of HA reactor fluctuated around 50%, while in stage 2 it declined from 51.50% to 21.58% as the concentration of dyes increased. Illumina MiSeq sequencing analysis was performed to investigate the microbial community structure and diversity in the HA process under different dye conditions. The results revealed that different dyes (RB5 and RBBR) in HA process had significant influence on the microbial community structure at different taxonomic levels (from phylum to genus). Bacteroidetes , Proteobacteria and Firmicutes were dominant phyla in both two samples collected from two stages containing different dyes. The genera Klebsiella , Lactococcus , and Desulfovibrio might have potential ability of degrading both RB5 and RBBR under hydrolysis acidification condition, while Dysgonomonas sp. and Prevotella sp. might play important roles in RB5 and RBBR degradation, respectively, in this hydrolysis acidification process. [ABSTRACT FROM AUTHOR]