Maximum Color Research Articles

Influence of typical electrolytes on electrooxidation of bio-refractory reactive dye

Electrochemical oxidation is a promising alternative for the degradation of reactive dyestuffs in residual dyeing liquid, which contains organic dyes, as well as salts such as sodium chloride and sodium sulfate. In this work, three kinds of salts, Na2SO4, NaCl and FeSO4, were selected to study the influence of electrolytes on the electrochemical oxidation of recalcitrant reactive red X-3B, using graphite cathode and dimensionally stable anode or graphite anode. The removals of color and chemical oxygen demand have been evaluated. Color removals were 99.97% and 99.84% with graphite anode and dimensionally stable anode in Na2SO4 and NaCl electrolyte. The corresponding chemical oxygen demand removals were 93.60% and 100%. In contrast, the maximum color and chemical oxygen demand removals were 97.32% and 68.76% in FeSO4 electrolyte. It was found that a combination of NaCl and FeSO4 achieved complete oxygen demand removal for both graphite anode and dimensionally stable anode. During the electrochemical oxidation process, anode and electrolyte exhibited a great effect on pH variations. Based on the cyclic voltammetry and active oxidative species investigations, the oxidation of reactive red X-3B was attributed to indirect oxidation of active chlorine and reactive oxygen species.

Effect of Tea on Color Stability of Enamel Lesions Treated with Resin Infiltrant.

Objectives: This study aimed to assess the effect of tea on color stability of enamel lesions treated with resin infiltrant (RI). Materials and Methods: This in vitro, experimental study evaluated 30 extracted human third molars with no caries, cracks, or enamel defects. Enamel-dentin samples measuring 5 x 5 x 3 mm were prepared from the buccal surfaces of the teeth by a microtome. The samples were divided into three groups of 10 namely sound enamel, demineralized enamel, and demineralized enamel plus RI. White spot lesions (WSLs) were artificially created by immersing the samples in hydroxyethyl cellulose demineralizing gel with a pH of 4.5 for 4 days. Next, Icon RI was applied on the samples in group 3. The baseline color of the samples was measured using a spectrophotometer. They were immersed in tea solution 3 times a day, each time for 15 min, for a period of 2 weeks and then underwent colorimetry again. Data were analyzed using one-way ANOVA. Results: The maximum color change (∆E) was noted in demineralized enamel plus RI group (38.59±6.13) with significant differences with sound enamel (20.00±2.94) and demineralized enamel (25.27±7.47) groups (P<0.05). The difference between the latter two groups was not significant (P>0.05). Conclusion: Within the limitations of this in vitro study, the results showed that tea solution caused clinically unacceptable color change in all groups. However, the color stability of WSLs treated with RI was significantly lower than other groups following immersion in tea solution.

Simultaneous electrochemical decolorization of Acid Red 33, Reactive Orange 7, Acid Yellow 3 and Malachite Green dyes by electrophoretically prepared Ti/nanoZnO-MWCNTs anode: Experimental design

Abstract Water pollution by pollutants released from various industries is one of the environmental concerns, however, electrochemical oxidation (EO) is a promising option for wastewaters treatment. Anode material is the main parameter in this process, as well as usually, real wastewaters are mixtures of various pollutants. Thus the overall goal of this work is to modification of the titanium substrate by ZnO-MWCNTs nanocomposite through electrophoretic deposition technique for the first time and evaluate its performance in simultaneous decolorization of mixture of dyes including Acid Red 33 (AR33), Reactive Orange 7 (RO7), Acid Yellow 3 (AY3) and Malachite Green (MG). The obtained results of electrode characterizing analyses revealed that the presence of coated ZnO-MWCNTs nanocomposite layer on the titanium surface promoted the electrode properties such as conductivity, stability and electro-catalytic activity which are important in EO processes. To investigate the color removal efficiencies of dyes mixture, the response surface methodology and partial least square as a multivariate calibration method were employed to optimize the EO process and determination of dyes concentration, respectively. Maximum color removal efficiencies were 43.11%, 25.98%, 27.21% and 100% for AR33, RO7, AY3, and MG respectively at optimum conditions. According to the results, the Ti/nanoZnO-MWCNTs electrode has great potential for the decolorization and degradation of various dyes.

Effect of drying techniques and operating conditions on the retention of color, phenolics, and antioxidant properties in dried lemon scented tea tree ( Leptospermum petersonii ) leaves

Leptospermum petersonii is an aromatic native Australian plant that has been traditionally used as a medicine and a tea; however, its application in food products is increasing. The aim of this study was to investigate the most suitable and energy-efficient drying conditions to retain phenolic compounds, antioxidant properties, and, color in dried Leptospermum petersonii leaves. In this study, six drying techniques were investigated including hot air, vacuum, microwave, freeze, sun, and shade. Results showed that freeze-drying retained maximum color, phenolic compounds, and, antioxidant capacity, however, it consumed the most time and energy. Conversely, microwave drying (960 W, 0.1 hr) used the least amount of time and energy yet retained the second-highest levels of phenolics and antioxidant capacity. In conclusion, microwave drying is suggested for large-scale drying. This method is economical and it is approximately 480 times and 1,700 times more time and energy efficient compared to freeze-drying. Novelty impact statement Microwave and freeze-drying is the most and least energy efficient method respectively There is a strong correlation between phytochemical and antioxidant capacity Freeze-drying retains maximum color properties, phenolic compounds, and antioxidant capacity

Color Prediction for Pre-Colored Cotton Fiber Blends Based on Improved Kubelka-Munk Double-Constant Theory

The accuracy of color prediction results for pre-colored fiber blends is critical in the textile industry. In this paper, we attempt to investigate a feasible method for predicting the color of pre-colored fibers blends. Five pre-colored cotton fibers were divided into two groups, one for achromatic primaries (white and black) and one for chromatic primaries (red, blue, and yellow). Their respective absorption coefficient (K) and scattering coefficient (S) were calculated by the least squares method from the prepared fiber blends samples. The color information of the 34 test blending samples including two-primary and three-primary was predicted by the improved Kubelka-Munk (K-M) double-constant theory. Comparing with the measurement results, the minimum and maximum DE00 color differences were 0.215 and 1.890. The variance of color difference for two-primary samples was 0.128 and for three-primary samples was 0.154, both were smaller than that obtained by the K-M theory relative value method, the Stearns-Noechel (S-N) model, revised S-N models, and the Friele model. The results show that the improved K-M double-constant theory can be used to better predict the color blending effect of pre-colored fibers.

Local edge coloring of graphs

Let be a graph. A local edge coloring of G is a proper edge coloring such that for each subset S of E(G) with there exist edges such that where ns is the number of copies of P 3 in the edge induced subgraph The maximum color assigned by a local edge coloring c to an edge of G is called the value of c and is denoted by The local edge chromatic number of G is where the minimum is taken over all local edge colorings c of G. In this article, we derive bounds and many results based on local edge coloring.

Wastewater Treatment Using a Natural Coagulant (Moringa Oleifera Seeds): Optimization Through Response Surface Methodology

The high expense of chemical coagulant-treated water forces most people in rural regions rely on easily available sources, which are usually of poor quality and expose them to waterborne infections. According to this statement, the purpose of this study was to confirm the efficacy of extracting powder Moringa oleifera seeds, which are widely available in rural regions. The experiment was done based on random design load of 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6g/500ml of powder extracted from Moringa seeds. Chemical oxygen demand (COD), color and turbidity were determined for both acidic and basic characteristics of wastewater. The optimum dosage of Moringa oleifera was 0.4g/500ml in both characteristics of waste water in case of color and turbidity. Moringa airfare maximum reduction in turbidity, color and COD in acidic waste water was 98%, 90.76% and 65.8% respectively. And maximum reduction turbidity, color and COD in basic waste water were 99.5%, 97.7% and 65.82% respectively. The study was demonstrated that, the application of RSM for seeking optimum condition in the coagulation process for treatment of wastewater. Moringa seed powder works best with 7-9 pH range. All the results showed that, Moringa Oliver seeds were very effective for the removal of impurities. So, the researcher and the respective body give attention use of these trees in a wide application area.

Multiple Reuse of Electrocoagulation Treated Reactive Dyeing Wash-Off: Colorimetric Properties and Water Saving

Dyeing wash-off operations in textile industries quite water intensive resulting into the generation of highly polluted wastewater. This study evaluated the treatment efficiency of electrocoagulation process to decolorize the synthetic effluent of CI Reactive Yellow 145 and then, the treated effluent was reused for 08 subsequent wash-off cycles of textile dyeing. The process parameters (Electrolysis time, applied current density and pH) were optimized and the maximum colour removal efficiency (98%) was achieved at pH 7, 10 minutes treatment time and current density of 90 A/m2. The fabric quality was assessed in terms of Colour difference and wash fastness properties. The Colour difference values of all dyed fabric samples up to 8 reuse cycles were ranged 0.38 to 0.85 which is industrially acceptable quality limit (ΔEcmc < 1). The wash fastness and Colour strength properties were also comparable to that of conventionally washed off fabric samples. However, an increase in pH, COD, TDS and turbidity was observed after every reuse but it did not deteriorate the quality of dyeing. This approach of reuse of electrocoagulation treated dye wash-off liquor up to 8 cycles provides a sustainable solution for textile industry.

An ink-jet printed dual-CD ratiometric fluorescent paper-based sensor for the visual detection of Cu2.

Copper ion (Cu2+) plays an important role in the human body because it is beneficial for metabolism. However, an excessive or slight amount of Cu2+ can cause various symptoms. Therefore, it is necessary for human health to realize the trace and visual detection of Cu2+. Referring to traditional fluorescence test papers, the qualitative and semi-quantitative detection of Cu2+ could be realized by a dual-carbon dots (CDs) ratiometric fluorescent paper-based sensor with the advantages of environmental protection, portability and low cost. In this paper, the inkjet-printed test paper with the best mixing ratio of the two CDs has been researched to maximize the spectral energy transfer of ion detection (maximum color gamut expansion). Among them, the preparation method of b-CDs has been improved, increasing the photoluminescence quantum yield (PLQY) to 88.9%. The sensitivity detection limit of the double emission ratio sensor was 0.15 nM in solution, and the human eye can distinguish at least 3 μmol L−1 Cu2+ in the paper-based sensor. Compared with the traditional single-emission sensor, the human eye was more sensitive to the color change of the emission ratio sensor. The results indicate that we not only realized the micro detection of Cu2+ with convenient methods, but also provided a promising strategy for the visual detection of Cu2+.

Influence of Autochthonous and Commercial Yeast Strains on Fermentation and Quality of Wines Produced from Vranec and Cabernet Sauvignon Grape Varieties from Tikveš Wine-Growing Region, Republic of North Macedonia

Two autochthonous yeast strains called F-8 and F-78 (isolated and selected from the Tikves wine-producing region) were inoculated in wine musts from Vranec and Cabernet Sauvignon grape varieties. The fermentation process and quality of the produced wines were compared to the wines produced from the same grape varieties, but with a commercial yeast strain (D-80). The fermentation process was undertaken at 23–25 °C for 16 days. The highest alcohol content was detected in Vranec and Cabernet Sauvignon wines fermented with autochthonous F-8 yeast strain. Conversely, Vranec wine fermented by the F-78 yeast strain contained the lowest alcohol content (14.11%). The low sugar amount (2–3 g/L) in both grape varieties is indicated the production of dry wines. The total amount of phenolic compounds was significantly higher in Vranec wines. Unlike the alcohol content, Vranec wine produced by commercial yeast strain D-80 indicated the highest concentration of total phenolic compounds (1450 mg/L) and total anthocyanins (572 mg/L), while the lowest concentrations were observed in wine fermented by autochthonous yeast strain F-78 (1612 mg/L and 470 mg/L, respectively). The maximum color intensity was measured in the Vranec wine fermented by autochthonous yeast strain F-8, while wines from Cabernet Sauvignon grape variety fermented with the same yeast strain F-8 and commercial yeast strain D-80 had comparable values in terms of color intensity.

Influence of toothbrush abrasion and surface treatments on the color and translucency of resin infiltrated hybrid ceramics.

PURPOSEThe study compared the color change, lightness, and translucency of hybrid resin ceramics exposed to toothbrush abrasion and surface treatment.MATERIALS AND METHODSFour hybrid ceramics [Lava Ultimate (LU), Vita Enamic (EN), Shofu HC (SH), and Crystal Ultra (CU)] were compared with a glass-ceramic (Vita Mark II) control. One hundred and twenty specimen blocks were prepared using a precision saw machine. Specimens in each material were divided into four subgroups based on the surface treatment (polishing or staining) and a storage medium (water or citric acid). Simulated tooth brushing with a mixture of 100 RDA (radioactive abrasives) with 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Measurements for the color change, lightness, and translucency were measured after toothbrushing using a spectrophotometer. Statistical analysis compared outcomes using paired t-test, ANOVA, and Tukey post hoc test.RESULTSThe maximum color change was identified in SH (stained acid) [1.44 (0.40)], whereas the lowest was identified in EN (polished water) [0.66 (0.16)] material. The maximum and minimum loss of surface translucency was observed in SH (polished water) [12.3 (0.52)] and EN (stained acid) [6.5 (0.55)] specimens, respectively. Lastly, loss of lightness was the highest in VM (polished acid) [69 (0.95)], whereas the lowest was observed in CU (stained water) [56.7 (0.86)].CONCLUSIONThe comparison presented a significant effect of toothbrush abrasion on translucency and lightness of the hybrid resin ceramics. Color change was not significantly influenced irrespective of the storage medium employed. Surface staining demonstrated the preservation and stability of color and optical properties under the influence of toothbrush abrasion and chemical trauma.

Facial unique-maximum edge and total coloring of plane graphs

An edge coloring of a plane graph is facial if every two facially adjacent edges (i.e., the edges that are adjacent and consecutive in a cyclic order around their common end vertex) receive different colors. A total coloring of a plane graph is facial if every two adjacent vertices, every two facially adjacent edges and every two incident elements receive different colors. A coloring of a plane graph (using linearly ordered color set) is unique-maximum if, for each face, the maximum color on its elements is used exactly once. In the paper it is proven, that every 2-edge-connected plane graph is facially unique-maximum 4-edge-colorable and facially unique-maximum 6-total-colorable, and that the bounds 4 and 6, respectively, are best possible. Furthermore, every plane graph is facially unique-maximum 6-edge-choosable and facially unique-maximum 8-total-choosable.

Decolorization and phytotoxicity reduction of reactive blue 40 dye in real textile wastewater by active consortium: Anaerobic/aerobic algal-bacterial-probiotic bioreactor

The textile dyeing and printing industries has led to extensive environmental pollution and severely threatens ecosystems. The best microbial species for such application was selected among the isolated bacterial populations by conducting CI Reactive Blue 40 (CI RB 40) batch degradation studies with the bacterial-algal-probiotic strains. In this study, three suitable species (Pseudomonas putida, Chlorella and Lactobacillus plantarum) were applied to degrade and detoxify CI RB 40, a reactive diazo dye in Real Textile Wastewater, used in textile dyeing industry worldwide. Process parameters were optimized using Response Surface Methodology and under the optimum conditions (e.g., inoculum size of 10%), temperature of 35 °C, 150 ppm, and time of 6 days). The maximum COD and color removal efficiencies, when tested with 1000 ppm of dye using batch reactors were found to be 89% and 99%, respectively. Our results showed also that bacteria had a high decolorization capacity. The regression analysis revealed a good match of the experimental data to the second-order polynomial with a high coefficient of determination (R2). UV–Visible and FTIR spectroscopy analysis confirmed the biodegradation of CI RB 40. Finally, toxicity of CIRB 40 before and after biodegradation was studied and the detoxification of CIRB 40 dye solution after biodegradation process was confirmed.

Comparison of color stability of two types of denture base resins in various food colorant solutions: An in vitro study

Background: Heat cured Polymethylmethacrylate (PMMA) and Lucitone are the most commonly used denture base resins but their discoloration results in esthetic problems. There is evidence that these resins get discolored on contact with coloring solutions due to sorption but very few studies report on the effect with food colorants. Hence, this study was conducted to evaluate and measure the effect of these food colorants on the denture base resins. Purpose: The color stability of two commercially available denture base acrylic resins (Trevalon & Lucitone) was studied in vitro. Materials and Methods : The specimens were exposed to solution of artificial saliva (control), mixture of artificial saliva and coffee solution and mixture of artificial saliva and turmeric solution. The color measurements were made at baseline (before immersion) and after 30 and 60 days of exposure to staining solutions and color characteristics compared with a white standard using a computer controlled spectrophotometer. Finally, the color stability was quantitatively measured again and color differences (?E) were calculated. Results: The results of discoloration were analyzed with ANOVA, and it indicated that all factors (time, material, and staining solution), and all possible interactions among them, were found to be statistically significant (p 3 solutions were slight and at trace level. Conclusions: All materials tested were acceptable from the standpoint of color stability for long term exposure to these food colorants. Trevalon® (PMMA), demonstrated maximum color stability as compared to Lucitone FRS and discoloration increased proportionally with immersion period. Keywords: Denture base, Color stability, Foodcolorant.

Non-extractive spectrophotometric determination of memantine HCl, clomipramine HCl and fluvoxamine maleate in pure form and in pharmaceutical products by ion-pair complex formation with rose bengal

The objective of this work is to develop a simple, sensitive and non-extractive spectrophotometric method for the determination of memantine HCl (MEM), clomipramine HCl (CLM) and fluvoxamine maleate (FLV). The proposed method was based on the formation of colored ion-pair complexes between the basic nitrogen of the target drugs and rose bengal (RB) dye in a weak acidic medium. The formed complexes were measured at 576nm for MEM, CLM and at 575nm for FLV. The reaction conditions were optimized to obtain the maximum color intensity. Beer's law was obeyed in the range of 2-20, 1-16 and 6-30μg/mL for MEM, CLM and FLV, respectively. The limit of detection (LOD) was 0.476, 0.185, 0.806 and the limit of quantitation (LOQ) was 1.443, 0.559 and 2.443 for MEM, CLM and FLV, respectively. The composition ratio of the ion-pair complexes was found to be 1:1 as determined by Job's method. The proposed method was applied successfully for the analysis of the cited drugs in pure and dosage forms. Results of the proposed method were statistically compared with the reported methods by applying student's t- and F-tests and no significant differences were observed.

Impact of diabetes mellitus on the early-phase arterial healing after drug-eluting stent implantation

BackgroundEarly arterial healing after drug-eluting stent (DES) implantation may enable short dual-antiplatelet therapy (DAPT) strategy. The impact of diabetes mellitus (DM) on this healing has not been elucidated. We used coronary angioscopy (CAS) to compare intravascular status of DM and non-DM patients in the early phase after DES implantation.MethodsThis study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients evaluated 3–5 months after DES implantation. We divided the lesion into two groups: DM (n = 149) and non-DM (n = 188). We assessed neointimal coverage (NIC) grades (dominant, maximum and minimum), thrombus adhesion and maximum yellow color grade. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.ResultsMinimum NIC grade was significantly lower in DM than in non-DM groups (p = 0.002), whereas dominant and maximum NIC grades were similar between them (p = 0.59 and p = 0.94, respectively), as were thrombus adhesion (44.3% vs. 38.8%, p = 0.32) and maximum yellow color grade (p = 0.78). A multivariate analysis demonstrated that DM was an independent predictor of minimum NIC of grade 0 (odds ratio: 2.14, 95% confidence interval: 1.19–3.86, p = 0.011).ConclusionsDM patients showed more uncovered struts than non-DM patients 3–5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applied to DM patients.

GaInP nanowire arrays for color conversion applications

Color conversion by (tapered) nanowire arrays fabricated in GaInP with bandgap emission in the red spectral region are investigated with blue and green source light LEDs in perspective. GaInP nano- and microstructures, fabricated using top-down pattern transfer methods, are derived from epitaxial Ga0.51In0.49P/GaAs stacks with pre-determined layer thicknesses. Substrate-free GaInP micro- and nanostructures obtained by selectively etching the GaAs sacrificial layers are then embedded in a transparent film to generate stand-alone color converting films for spectrophotometry and photoluminescence experiments. Finite-difference time-domain simulations and spectrophotometry measurements are used to design and validate the GaInP structures embedded in (stand-alone) transparent films for maximum light absorption and color conversion from blue (450 nm) and green (532 nm) to red (~ 660 nm) light, respectively. It is shown that (embedded) 1 μm-high GaInP nanowire arrays can be designed to absorb ~ 100% of 450 nm and 532 nm wavelength incident light. Room-temperature photoluminescence measurements with 405 nm and 532 nm laser excitation are used for proof-of-principle demonstration of color conversion from the embedded GaInP structures. The (tapered) GaInP nanowire arrays, despite very low fill factors (~ 24%), can out-perform the micro-arrays and bulk-like slabs due to a better in- and out-coupling of source and emitted light, respectively.

The Maximum Colorful Arborescence problem: How (computationally) hard can it be?

Given a vertex-colored arc-weighted directed acyclic graph G, the Maximum Colorful Subtree problem (or MCS) aims at finding an arborescence of maximum weight in G, in which no color appears more than once. The problem was originally introduced in [1] in the context of de novo identification of metabolites by tandem mass spectrometry. However, a thorough analysis of the initial motivation shows that the formal definition of MCS should be amended, since the input graph G actually possesses extra properties, which have been unexploited so far. This leads us to describe in this paper a more precise model that we call Maximum Colorful Arborescence (MCA), which we extensively study in terms of algorithmic complexity. In particular, we show that exploiting the implied Color Hierarchy Graph of the input graph G can lead to exact polynomial algorithms and approximation algorithms. We also develop Fixed-Parameter Tractable (FPT) algorithms for the problem parameterized by the “dual parameter” ℓC, defined as the minimum number of vertices of G which are not kept in the solution.

Impact of diabetes mellitus on the early phase arterial healing after drug-eluting stent implantation: a multicenter coronary angioscopic study

Abstract Background Diabetes mellitus (DM) is a strong risk factor for major cardiac and cerebrovascular events. In particular, coronary artery disease with DM is often complicated with complex lesions. Drug-eluting stents (DES) are mainly used for these lesions, and dual-antiplatelet therapy (DAPT) has been used to prevent stent thrombosis. Early arterial healing after DES implantation may enable short DAPT strategy. However, the impact of DM on the arterial healing in the early phase has not been elucidated to date. Purpose We evaluated the arterial healing in the early phase after DES implantation using coronary angioscopy (CAS) and compared the findings between DM and non-DM patients. Methods This study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients which were evaluated 3 to 5 months after DES implantation. Patients were divided into two groups: DM (149 lesions in 118 patients) versus non-DM groups (188 lesions in 152 patients). We assessed neointimal coverage (NIC) grades (maximum, minimum and dominant), thrombus adhesion and maximum yellow color of plaque underneath the stent. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as follows: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow. Results Minimum NIC coverage grade was lower in DM group than in non-DM group (P=0.002, Figure), while maximum and dominant NIC coverage grades were similar between them (P=0.94 and P=0.59, respectively). Thrombus adhesion (44.3% versus 38.8%, P=0.32) and maximum yellow color grade (P=0.78) were also similar between DM and non-DM groups. Even after the adjustment by the confounding factors such as follow-up duration and primary disease of acute coronary syndrome, DM was an independent factor predicting grade 0 of minimum NIC (odds ratio [OR] 1.83 [95% confidence interval 1.11–3.03], P=0.019). Conclusion DM patients showed less covered struts than non-DM patients 3 to 5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applicable to DM patients. Minimum neointimal coverage grade Funding Acknowledgement Type of funding source: None

Reactive Orange 16 dye degradation in anaerobic and aerobic MBBR coupled with ozonation: addressing pathways and performance

In this study, two treatment routes were investigated for degradation of the azo dye Reactive Orange 16 (RO16): biodegradation in an anaerobic MBBR (R1) and ozonation followed by biological treatment in an aerobic MBBR (R2). Along with the dye, glucose and nutrients were supplemented to the influent fed to R1 as carbon co-substrate and nitrogen source, respectively. In R1, maximum color removal of 61 ± 18% was achieved for 5 mg l−1 of dye, hydraulic retention time of 12 h and influent COD of 800 mg l−1. Moreover, RO16 biodegradation was limited by carbon source (glucose) and attached solids concentrations. Batch tests revealed that anaerobic biodegradation of the dye and glucose followed second-order kinetics and RO16 degradation constant increased as the initial COD was reduced. Considering the relatively low color removal achieved anaerobically, dye solutions (100 to 500 mg l−1) were ozonated, enabling fast discoloration of at least 97% within 20 min for the highest dye concentration. However, the low COD (50–75%) and TOC (35–40%) removals achieved indicate that only partial mineralization occurred. RO16 (500 mg l−1) ozonation products were identified, and a degradation pathway was proposed. Subsequently, the ozonated solutions were supplemented with glucose and nutrients and fed to R2. COD removal decreased considerably (from 92 to 81%) when ozonated solutions with original dye concentration of 500 mg l−1 were fed to R2, but ammonium removal remained fairly stable. Three compounds identified before biological treatment were not found in R2 effluent, suggesting that they were biodegraded.