Reactive Black 5 Removal Efficiency Research Articles

A Novel Method for the Highly Effective Removal of Binary Dyes from Colored Dyeing Wastewater by Periodic Reversal/Direct Current-Activated Persulfate

In recent years, electrochemical synergistic activation of persulfate (PDS) degradation technology has demonstrated significant potential in wastewater treatment applications. Given the challenges posed by the complex water quality, high COD content, and recalcitrant degradation of dyeing wastewater, this study aimed to evaluate the efficacy of iron/aluminum dual-electrode electrochemical activation of PDS for degrading simulated dyeing wastewater. The results showed that under optimal conditions, utilizing both periodic reversal and direct current electrochemical activation of PDS achieved removal rates of 99.2% and 98.3% for Reactive Black 5 (RB5) and Reactive Red X-3B (RRX-3B), respectively, demonstrating promising removal efficiency. Notably, the removal efficiency of RB5 surpassed that of RRX-3B, suggesting a dependence on initial concentration influencing reaction kinetics. Furthermore, full-spectrum scanning and quenching experiments revealed that RB5 and RRX-3B were primarily degraded through the potent oxidation action of SO4−· and ·OH, with a small number of intermediates present in the solution. Periodic reversal proved effective in mitigating electrode passivation and enhancing electrode longevity. This study provides a highly effective removal method of binary dyes from dyeing wastewater by periodic reversal Fe-Al dual-electrode electrochemical activation of PDS technology, offering valuable insights for sustainable treatment of dyeing wastewater with binary components.

Superior decomposition of xenobiotic RB5 dye using three-dimensional electrochemical treatment: Response surface methodology modelling, artificial intelligence, and machine learning-based optimisation approaches

The highly efficient electrochemical treatment technology for dye-polluted wastewater is one of hot research topics in industrial wastewater treatment. This study reported a three-dimensional electrochemical treatment process integrating graphite intercalation compound (GIC) adsorption, direct anodic oxidation, and ∙OH oxidation for decolourising Reactive Black 5 (RB5) from aqueous solutions. The electrochemical process was optimised using the novel progressive central composite design–response surface methodology (CCD–NPRSM), hybrid artificial neural network–extreme gradient boosting (hybrid ANN–XGBoost), and classification and regression trees (CART). CCD–NPRSM and hybrid ANN–XGBoost were employed to minimise errors in evaluating the electrochemical process involving three manipulated operational parameters: current density, electrolysis (treatment) time, and initial dye concentration. The optimised decolourisation efficiencies were 99.30%, 96.63%, and 99.14% for CCD–NPRSM, hybrid ANN–XGBoost, and CART, respectively, compared to the 98.46% RB5 removal rate observed experimentally under optimum conditions: approximately 20 mA/cm2 of current density, 20 min of electrolysis time, and 65 mg/L of RB5. The optimised mineralisation efficiencies ranged between 89% and 92% for different models based on total organic carbon (TOC). Experimental studies confirmed that the predictive efficiency of optimised models ranked in the descending order of hybrid ANN–XGBoost, CCD–NPRSM, and CART. Model validation using analysis of variance (ANOVA) revealed that hybrid ANN–XGBoost had a mean square error (MSE) and a coefficient of determination (R2) of approximately 0.014 and 0.998 respectively, for the RB5 removal efficiency, outperforming CCD–NPRSM with MSE and R2 of 0.518 and 0.998, respectively. Overall, the hybrid ANN–XGBoost approach is the most feasible technique for assessing the electrochemical treatment efficiency in RB5 dye wastewater decolourisation.

Synthesis of MMT−CuFe2O4 Composite as a Peroxymonosulfate Activator for the Degradation of Reactive Black 5

AbstractCopper ferrite nanoparticles loaded on montmorillonite (MMT−CuFe2O4) were prepared by co‐precipitation method and applied as catalyst for activation of peroxymonosulfate (PMS) in degradation of reactive black 5 (RB5). The maximum removal efficiency of RB5 completely depends on the operating parameters and the highest removal percentage was obtained at MMT−CuFe2O4 dosage of 250 mg/L, PMS concentration of 4 mM, initial RB5 concentration of 50 mg/L and time of 15 min. The presence of anions such as Cl−, NO3−, HCO3−, and SO42− showed a significant limitation in the degradation of RB5 in the MMT−CuFe2O4/PMS system. Trapping experiments showed that ⋅OH and SO4⋅− radicals were involved in the catalytic degradation of RB5, however ⋅OH is the major specie in the catalysis system. Consecutive cycles were considered for testing the reusability of MMT−CuFe2O4; its results showed the stability of five consecutive cycles. The toxicity test was evaluated using Daphnia magna and the results illustrated a substantial drop in the toxicity of the solution treated. The significant reduction of TOC during RB5 degradation and the production of SO42−, NH4+ and NO3− confirm the proper progress of pollutant mineralization. The high catalytic performance of the catalyst in a short time compared to other removal systems emphasizes that MMT−CuFe2O4 can be suggested as a promising catalyst for the degradation of RB5 from aqueous solutions.

Sodium hydroxide pre-treated Aspergillus flavus biomass for the removal of reactive black 5 and its toxicity evaluation

The present study was focused on the removal of Reactive Black 5 (RB5) from aqueous solution using pre treated Aspergillus flavus as a biosorbent. Pre-treatment of fungal biomass with 0.1 M sodium hydroxide facilitated the removal of dye effectively when compared to untreated fungal biomass. Optimum biosorption conditions for RB5 removal was determined as a function of dye concentration (50–400 mg/L), biosorbent concentration (100–500 mg/L), incubation time (1–7hrs), pH (3–8) and temperature (20–50 °C). At the optimum conditions, the maximum removal efficiency of RB5 achieved by NaOH pretreated A. flavus was 91%. The dye removal was studied kinetically and it obeys the pseudo-second order model and the experimental equilibrium data well fitted the Langmuir isotherm indicating monolayer adsorption of dye molecules on the biosorbent. The thermodynamic parameters such as a change in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were calculated and negative values of ΔG suggested that the dye removal process was spontaneous at all temperatures. Furthermore, the values of ΔH revealed that the adsorption process was endothermic. Recovery of RB5 from the fungal biomass was effective using 0.1 M Na2CO3 as an eluent. The interaction of adsorbate with biosorbent was analyzed using UV–Vis and FT-IR spectroscopy, SEM and XRD analyses. Phytotoxicity and microbial toxicity studies revealed the non-toxic nature of the treated dye solution. Hence, the fungal biomass pretreated with NaOH was efficient in decolorizing RB5 as well as composite raw industrial effluent generated from dyeing industries.

Development of Artificial Neural Network for Predicting The Photodegradation of Reactive Black 5 Dye

We applied a multilayer artificial neural network (ANN) developed using a Lavenberg–Marquadt algorithm to predict the photodegradation activity of the Reactive Black 5 (RB5) dye. A copper-doped titanium dioxide was employed as a photocatalyst. A copper doped titanium dioxide was synthesized through a wet-impregnation method. To optimize the network the operational parameters including the RB5 initial concentration, photocatalyst dose, irradiation time, hydrogen peroxide concentration, and visible light intensity were used as the input parameter. Removal efficiency of RB5 was selected as output. The number of neurons in the second hidden layer was optimized to determine the suitable ANN model structure for the RB5 removal. ANN based through Levenberg-Marquadth algorithm with structure 1-10-21-1 gave the best performance in this study. The criteria for the applicability of the model were the root mean square error (0.1) and coefficient of correlation (0.98275).

Electrochemical Oxidation of Azo Dye Wastewater Using Graphene-Based Electrode Materials.

Composite electrodes with different graphene (GN)/TiO² ratios and nano-activated carbon electrodes were prepared for electrocatalytic performance comparison. The electrodes were loaded with platinum (Pt) by use of chloroplatinic acid to promote their performance. Reactive Black 5 (RBk5) dye wastewater was treated as a challenging pollutant by use of advanced electrochemical oxidation technology. The composite materials were characterized by Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Disperse Spectroscopy (EDS). Results showed that the graphene electrode was prepared successfully and verified because all elements were uniformly loaded on the conductive carbon cloth. The effects of several operating parameters including material types, pH, initial concentration of RBk5, and current density on the removal performance of RBk5 were also assessed. The supporting electrolyte was NaCl solution of 1 g L-1. The concentration of RBk5 was detected using an ultraviolet spectrophotometer with a detection wavelength of 600 nm. The optimum parameters of the experiment were GN/TiO₂ ratio of 1:4 and pH of 6.6. The removal efficiency of RBk5 could be higher than 95% under an initial concentration of RBk5 of 5 ppm and a current density of 2.5 mA·cm-2 when reaction time was 30 min.

Synthesis and application of magnetic iron oxide nanoparticles on the removal of Reactive Black 5: Reaction mechanism, temperature and pH effects

The water pollution created by the textiles industry contains a large amount of azo dyes, such as Reactive Black 5 (RB5), which are recalcitrant in the environment. The feasibility and major mechanism of iron oxide nanoparticles (IONPs) in the removal of RB5 were investigated in this study. Our synthesized IONPs (17 nm) had a high surface area of 77.1 m2/g, possessed a magnetite crystal structure, and had a pHzpc of 5.56. The main removal mechanism of RB5 with IONPs was adsorption by electrostatic attraction. The adsorption isotherm of RB5 on IONPs fitted the Langmuir and Freundlich equations well. The removal efficiency of RB5 with IONPs decreased with increasing the initial RB5 concentrations but increased with the increase of NP dosage and temperature. The average adsorption enthalpy was 24 kJ/mol. As the pH increased, the removal efficiency of IONPs decreased due to electrostatic repulsion. The high magnetic property of our iron oxide NPs results in the NPs being easily recyclable from water: the NPs retained a 90% removal efficiency after ten cycles, suggesting their great potential for use in pollution treatments.

Reactive Black 5 as electron donor and/or electron acceptor in dual chamber of solar photocatalytic fuel cell

The role of azo dye Reactive Black 5 (RB5) as an electron donor and/or electron acceptor could be distinguished in dual chamber of photocatalytic fuel cell (PFC). The introduction of RB5 in anode chamber increased the voltage generation in the system since degradation of RB5 might produce electrons which also would transfer through external circuit to the cathode chamber. The removal efficiency of RB5 with open and closed circuit was 8.5% and 13.6%, respectively and removal efficiency for open circuit was low due to the fact that recombination of electron-hole pairs might happen in anode chamber since without connection to the cathode, electron cannot be transferred. The degradation of RB5 in cathode chamber with absence of oxygen showed that electrons from anode chamber was accepted by dye molecules to break its azo bond. The presence of oxygen in cathode chamber would improve the oxygen reduction rate which occurred at Platinum-loaded carbon (Pt/C) cathode electrode. The Voc, Jsc and Pmax for different condition of ultrapure water at cathode chamber also affected their fill factor. The transportation of protons to cathode chamber through Nafion membrane could decrease the pH of ultrapure water in cathode chamber and undergo hydrogen evolution reaction in the absence of oxygen which then increased degradation rate of RB5 as well as its electricity generation.

Synthesis and characterization of Fe0/TiO2 nano-composites for ultrasound assisted enhanced catalytic degradation of reactive black 5 in aqueous solutions

In the present study, nanocomposites (NCs) of zero valent iron nanoparticles (Fe0 NPs) and titanium dioxide nanoparticles (Fe0/TiO2 NCs) were prepared by coating Fe0 NPs onto the surface of TiO2 NPs through borohydride reduction of Fe(II) salt for the ultrasound assisted removal/ degradation of reactive black 5 (RB5) dye from aqueous solutions. Morphological and structural characterizations of the Fe0/TiO2 NCs were performed by FE-SEM, HR-TEM, XRD, XPS and Brunauer–Emmett–Teller (BET) method. The Fe0/TiO2 NCs exhibited highly efficient ultrasonic degradation/decolourization of RB5, compared to TiO2 NPs counterpart. In the presence of ultrasonic irradiation, 0.25g/L of Fe0/TiO2 NCs showed complete removal of 100mg/L RB5 dye within 10min of reaction. An increase in RB5 removal efficiency was obtained with decrease in initial concentration and solution pH, whereas it was decreased with decrease in the amount of Fe0/TiO2 NCs. The rate of RB5 degradation was in good agreement with the pseudo-first-order kinetic model. Higher RB5 removal efficiency was observed at a higher ultrasonic power level. Coexisting NO3− and SO42− ions had only a minor impact on the removal of RB5, whereas, CO32− ions considerably affected the% removal of RB5 using Fe0/TiO2 NCs. Regeneration/reusability experiments revealed that Fe0/TiO2 NCs could be reused efficiently up to 7th removal cycle without considerable loss of their original RB5 removal performance. Liquid chromatography–mass spectrometry (LC–MS) study, used for the detection of the RB5 degradation products showed that the degradation mechanism proceeds via the reductive cleavage of the azo linkage of the dye which produced 1-sulfonic, 2(4-aminobenzenesulfonyl) ethanol as the stable end product.

Mineralization of diazo dye (Reactive Black 5) in wastewater using recirculated up-flow constructed wetland reactor

Abstract Application of a sequential anaerobic and aerobic process in a constructed wetland can enhance the treatment performance of textile wastewater. In this study, two laboratory-scale recirculated up-flow constructed wetland (UFCW) reactors planted with Phragmites australis were constructed to investigate the treatment performance between aerated and non-aerated reactors for treating 50 mg/L Reactive Black 5 (RB5)-containing wastewater. Results showed that the non-aerated reactor demonstrated an almost entire anaerobic environment yielded a better RB5 removal efficiency (89%) compared to the aerated reactor (81%). However, the aerated reactor performed higher removal on chemical oxygen demand (COD) and aromatic amines than the non-aerated reactor. Proper design ratio of anaerobic/aerobic region in UFCW is a key to accomplish not only color reduction but also COD and aromatic amines in textile wastewater treatment.

Adsorption with biodegradation for decolorization of reactive black 5 by Funalia trogii 200800 on a fly ash-chitosan medium in a fluidized bed bioreactor-kinetic model and reactor performance

A non-steady-state mathematical model system for the kinetics of adsorption and biodegradation of reactive black 5 (RB5) by Funalia trogii (F. trogii) ATCC 200800 biofilm on fly ash-chitosan bead in the fluidized bed process was derived. The mechanisms in the model system included adsorption by fly ash-chitosan beads, biodegradation by F. trogii cells and mass transport diffusion. Batch kinetic tests were independently performed to determine surface diffusivity of RB5, adsorption parameters for RB5 and biokinetic parameters of F. trogii ATCC 200800. A column test was conducted using a continuous-flow fluidized bed reactor with a recycling pump to approximate a completely-mixed flow reactor for model verification. The experimental results indicated that F. trogii biofilm bioregenerated the fly ash-chitosan beads after attached F. trogii has grown significantly. The removal efficiency of RB5 was about 95 % when RB5 concentration in the effluent was approximately 0.34 mg/L at a steady-state condition. The concentration of suspended F. trogii cells reached up to about 1.74 mg/L while the thickness of attached F. trogii cells was estimated to be 80 μm at a steady-state condition by model prediction. The comparisons of experimental data and model prediction show that the model system for adsorption and biodegradation of RB5 can predict the experimental results well. The approaches of experiments and mathematical modeling in this study can be applied to design a full-scale fluidized bed process to treat reactive dye in textile wastewater.

Degradation of reactive dyes in a photocatalytic circulating‐bed biofilm reactor

Decolorization and mineralization of reactive dyes by intimately coupled TiO₂-photocatalysis and biodegradation (ICPB) on a novel TiO₂-coated biofilm carrier were investigated in a photocatalytic circulating-bed biofilm reactor (PCBBR). Two typical reactive dyes--Reactive Black 5 (RB5) and Reactive Yellow 86 (RY86)--showed similar first-order kinetics when being photocatalytically decolorized at low pH (~4-5) in batch experiments. Photocatalytic decolorization was inhibited at neutral pH in the presence of phosphate or carbonate buffer, presumably due to electrostatic repulsion from negatively charged surface sites on TiO₂, radical scavenging by phosphate or carbonate, or both. Therefore, continuous PCBBR experiments were carried out at a low pH (~4.5) to maintain high photocatalytic efficiency. In the PCBBR, photocatalysis alone with TiO₂-coated carriers could remove target compound RB5 and COD by 97% and 47%, respectively. Addition of biofilm inside macroporous carriers maintained a similar RB5 removal efficiency, but COD removal increased to 65%, which is evidence of ICPB despite the low pH. ICPB was further proven by finding microorganisms inside carriers at the end of the PCBBR experiments. A proposed ICPB pathway for RB5 suggests that a major intermediate, a naphthol derivative, was responsible for most of the residual COD, while most of the nitrogen in the azo-bonds (-N=N-) was oxidized to N₂.

Biosorption of Reactive Black 5 from aqueous solution using acid-treated biomass from potato peel waste

The goal of this study was to survey the feasibility of the biosorption of Reactive Black 5 (RB5) from aqueous solutions using biomass prepared from potato peel waste. Adsorption isotherms were constructed, and the kinetics of dye adsorption were studied. Langmuir and Freundlich isotherms were constructed, and pseudo-first order, pseudo-second order, and modified pseudo-first order kinetic models were studied. Maximum adsorption (85.5%) was observed at a pH of 3, and uptake decreased with increasing pH. The biosorption of RB5 increased with increasing contact time and reached equilibrium after two hours. RB5 removal efficiency decreased with an increase in the initial dye concentration, but the uptake of dye increased. Adsorption data conformed to the Langmuir isotherm model and pseudo-first order kinetics.

Performance and Kinetic Study on Bioremediation of Diazo Dye (Reactive Black 5) in Wastewater Using Spent GAC–Biofilm Sequencing Batch Reactor

Combinations of sequential anaerobic and aerobic process enhance the treatment of textile wastewater. The aim of this study was to investigate the treatment of diazo dye Reactive Black 5 (RB5)-containing wastewater using granular activated carbon (GAC)–biofilm sequencing batch reactor (SBR) as an integration of aerobic and anaerobic process in a single reactor. The GAC–biofilm SBR system demonstrated higher removal of COD, RB5 and aromatic amines. It was observed that the RB5 removal efficiency improved as the concentration of co-substrate in the influent increased. The alternative aeration introduced into the bioreactor enhanced mineralization of aromatic amines. Degradation of RB5 and co-substrate followed second-order kinetic and the constant (k2) values for COD and RB5 decreased from 0.002 to 0.001 and 0.004 to 0.001 l/mg h, respectively, as the RB5 concentration increased from 100 to 200 mg/l in the GAC–biofilm SBR system.

Fast and efficient removal of Reactive Black 5 from aqueous solution by a combined method of ultrasound and sorption process

Removal of Reactive Black 5 (RB5) from aqueous solutions was carried by the sorption process in the presence and in the absence of ultrasound. Sorption of the dye on the solid phase was investigated in a series of batch sorption experiments to determine the influence of different parameters such as contact time, amount of sorbent and concentration of pollutant on the removal efficiency of RB5 with and without ultrasound. The experimental data were fitted properly to the Freundlich model and the isotherm constants were 28.2 and 7.4 for kf and 0.13 and 0.38 for 1/n in the presence and in the absence of ultrasound (20kHz) respectively. The data were analyzed with different sorption kinetic models and were better fitted with a pseudo-second-order kinetic model. Two ultrasonic generators at 20 and 500kHz were used for sonication of the system. This investigation also reveals that RB5 can be removed by higher frequency apparatus (500kHz) without sorbent in about 60min sonication. The rate of removal was higher at the higher frequency than at the lower one.