Reactive Brilliant Blue KN-R Research Articles

Application of soybean residue (okara) as a low-cost adsorbent for reactive dye removal from aqueous solution

This study investigated the feasibility of using okara as a low-cost adsorbent for the removal of Reactive Brilliant Blue KN-R (RBB), a typical reactive dye, from aqueous solution. Batch adsorption experiments were conducted to evaluate the effects of pH, adsorbent dosage, initial dye concentration, and temperature. It was proved that strong acidic condition was favorable for the adsorption process and the optimal pH was 2.0. Langmuir–Freundlich (L–F) isotherm fitted well with the equilibrium data. The maximum adsorption capacity determined from the L–F isotherm was 68.67, 159.60, and 402.58 mg/g at 20, 35, and 50°C, respectively. Kinetic studies showed that adsorption of RBB followed the pseudo-second-order kinetic model, both boundary layer diffusion and intra-particle diffusion might affect the adsorption rate. Thermodynamic study demonstrated the spontaneous and endothermic natures of the adsorption process. Fourier transform infrared analysis revealed that chemical functional groups (e.g. amine, hydroxyl, carboxyl, phosphate, and ether) on okara would be the active binding sites for adsorption of RBB. The results showed that okara could be effectively used as a low-cost and alternative adsorbent for the removal of RBB from wastewater.

Preparation of Fly Ash/Nano-ZnO Composite and its Adsorption Properties for Reactive Dyes from Aqueous Solution

The fly ash (FA)/nano-ZnO composite was prepared by chemical precipitation method using waste FA, ZnSO4 and (NH4)2CO3 as raw materials and further analyzed by specific surface area and XRD. effects of important preparation conditions on the dye adsorption capacity of the composite were investigated. The results show that the FA/nano-ZnO composite obtained under optimal conditions of FA/ZnO mass ratio of 1:0.5, reaction and standing 2h at 60°C and calcining time of 3h at 250°C is a high efficient adsorbent and has much more higher adsorption capacities on 4 kinds of reactive dyes, reactive turquoise blue KN-G, reactive brilliant blue KN-R, reactive brilliant red X-3B and reactive brilliant red KD-8B from aqueous solution with 61.64mg/g, 46.36mg/g, 43.27mg/g and 31.18mg/g which are increased about 14, 32, 33 and 32 times than that of FA, respectively.

Synthesis, Characterization, and Photocatalytic Activity of N-Doped ZnO/ZnS Composites

The aim of the present study is to enhance photocatalytic performance of ZnO semiconductor by comodification with doping of nonmetal ions and coupling with another semiconductor. Therefore, we synthesized the N-doped ZnO/ZnS photocatalysts via a simple heat-treatment approach using L-cysteine as N and S source in this work. Anthraquinone dye (reactive brilliant blue KNR) is employed as the model contaminants to evaluate the photocatalytic activity of as-synthesized samples under sunlight illumination. The N-doped ZnO/ZnS synthesized by this method shows better photocatalytic activity as compared to that of pure ZnO. The enhanced photocatalytic activity of the N-doped ZnO/ZnS composites may be related to the existence of N doping, ZnS/ZnO heterostructure, and covered abundant carbon species on the photocatalyst surface, which causing high absorption efficiency of light, efficient separation of electron-hole pairs, and quick surface reaction in doped ZnO.

Decolorization of Reactive Brilliant Blue KN-R by Immobilized Cells of <i>Rhodocyclus gelatinosus</i>

Reactive Brilliant Blue KN-R is a typical kind of anthraquinone dye and in common use in textile, dyeing, and printing industries in China, which is difficult to degrade because of its conjugated structure. The decolorization of KN-R was investigated using Ca-alginate immobilized cells of Rhodocyclus gelatinosus XL-1 under anaerobic conditions. For KN-R decolorization by immobilized cells, the suitable pH is 5-8 and the suitable temperature is 25-40 °C. Immobilized cells could decolorize KN-R by co-metabolism in the presence of peptone, and the enhancement of peptone concentration was beneficial for anaerobic decolorization. Metal ions affected the metabolic activity of immobilized cells of R. gelatinosus XL-1. The activity of KN-R decolorization was appreciably increased by Mg2+ and Cr3+, but severely inhibited by Cu2+ and Ag+. The maximum absorption peak in visible spectrum shifted from 595 to 453 nm during KN-R decolorization, indicating the formation of the intermediate product.

Hydrothermal Preparation, Characterization and Photocatalytic Properties of C, N Co-Doped ZnO/ZnS Composites

C, N, S co-doped ZnO/ZnS composites were prepared by hydrothermal method using ZnSO4 and L-cysteine as raw materials, and investigated by UV-vis DRS, XRD, XPS. The results showed that C, N, S have successfully doped onto ZnO and substituted O of crystal lattice during hydrothermal process. The resulting co-doped ZnO composites exhibit significantly higher photocatalytic activity (45%) than that of pure ZnO (<5%) for degradation of reactive brilliant blue KN-R aqueous solution under simulative solar irradiation. The enhancement of photocatalytic performance of co-doped composites can be attributed to the reducing of electron-hole pair recombination and narrowed band gap.

Microwave Assisted Hydrothermal Synthesis and Characterization of N, S Co-Doped ZnO Photocatalyst

The N, S codoped ZnO was synthesized by microwave assisted hydrothermal method. The N, S codoping narrowed the band gap of ZnO (formed impurity states in the band gap), hence shift light response to range of visible light. Furthermore, the doped ZnO exhibits significantly higher photocatalytic activity than that of pure ZnO for degradation of reactive brilliant blue KN-R aqueous solution under simulative solar irradiation.

Color Removal of Reactive Brilliant Blue KN-R Simulated Dye Wastewater by Using Novel Flocculants

In this study, five novel flocculants, QTRY-02, DC-491, Fennofix K97, BWD-01 and MD-03 were chosen to treat Reactive Brilliant Blue KN-R simulated wastewater by jar tests. The effect of flocculant dosage, initial pH, solution temperature of simulated dye wastewater and sedimentaion time on the color removal was examined respectively. The maximum color removal efficiency of KN-R was over 82% after 20 minutes of sedimentation and the optimal dosage was 150mg/L for all flocculants. In the pH range from 3 to 11, small changes in the color removal efficiency for QTRY-02. While for BWD-01, the efficiency increased from 67.3% to 88.3%. For both QTRY-02 and MD-04, decolorization efficiency increased as the solution temperature increased from 10°C to 50°C and the same result appeared when prolonging the sedimentation time from 1 to 12 hours.

Hydrothermal Synthesis of ZnO/Zn Composites with Enhanced Photocatalytic Performance

ZnO/Zn composites photocatalysts were prepared by hydrothermal method using Zn powder as raw material, and the morphology, structure, and photocatalytic performance of composites were investigated. The results showed that the ZnO nanoparticles were produced at the surface of Zn metal powder during hydrothermal process. The thickness of ZnO outer layer (internal metal-semiconductor interfaces) can be controlled by varying hydrothermal treatment time. The resulting ZnO/Zn composites exhibit significantly higher photocatalytic activity than that of pure ZnO for degradation of anthraquinone dye (reactive brilliant blue KN-R) aqueous solution under ultraviolet light irradiation. The enhancement of photocatalytic performance of ZnO/Zn composites can be attributed to the formation of internal metal-semiconductor interfaces. The designed fabrication procedure is simple, feasible, and universal for a series of oxide/metal with controlled microstructure and improved performances.

Degradation of Reactive Brilliant Blue KN-R by Zero-Valent Iron/Activated Carbon Combined with Ultrasound

The treatment of Reactive Brilliant Blue KN-R in wastewater was conducted by using the zero-valent iron/activated carbon (Fe0/AC) combined with ultrasound (US). Although ultrasound alone had a little effect on the KN-R degradation and Fe0/AC had some disadvantages when it acted on the KN-R, the efficiency of the degradation was dramatically enhanced which used the combination of Fe0/AC /U.S. that also could eliminate the shortcomings. The decolorization percentage was nearly up to 100% and the COD removal rate has approached to 87.38%.

Synthesis, characterization and photocatalytic activity of Cu-doped Zn/ZnO photocatalyst with carbon modification

Herein, we report the preparation of Cu-doped Zn/ZnO composites with carbon modification via a simple replacement–hydrothermal method using Zn powder and CuSO4·5H2O as raw materials. The as-synthesized composites were characterized by powder X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). The results showed that Cu doping promotes crystal growth of ZnO, inhibits phase transfer of metallic Zn to ZnO, enhances the optical absorption in the visible region and reduces the recombination of photogenerated electrons and holes. Interestingly, CO2 dissolved in solution was converted to carbon adhered onto the composite surface (supported by the XPS data). The abundant carbon species present on the composite surface is favorable for surface chemical reactions because it can trap or adsorb reactants which facilitate the transfer of reactants to active sites. The photocatalytic efficiency of the as-synthesized catalysts was evaluated by the degradation of anthraquinone dye (reactive brilliant blue KN-R) in solution under sunlight irradiation. The degradation results revealed that the Cu-doped Zn/ZnO composites have better photocatalytic activities than those of ZnO and Zn/ZnO. The enhancement of the photocatalytic activity of the composites can be attributed to the existence of Cu doping, the Zn/ZnO hetero-structure and covered carbon on the surface of the photocatalysts, which causes electrons to be easily excited from the valence band to the conduction band and efficient separation of electron–hole pairs, as well as quick surface reactions in doped ZnO. Furthermore, a possible growth mechanism of the Cu-doped Zn/ZnO composites with carbon modification was proposed.

Preparation of Polyaniline Supported TiO<sub>2</sub> Photocatalyst and its Photocatalytic Property

A polyaniline supported titanium dioxide photocatalyst was prepared by an impregnation-hydrothermal process and characterized by powder X-ray diffraction, transmission electron microscopy and UV-visible spectroscopy. It was found that the TiO2 nanoparticles were well dispersed on the surface of the polyaniline and the photocatalyst has a stronger absorption compared with that of pure TiO2 over the whole of the visible spectrum. The photocatalyst exhibited higher photocatalytic activity than pure TiO2 for the photodegradation of solutions of the anthraquinone dye, reactive brilliant blue KN-R, under visible light irradiation.

Preparation of Polyaniline–ZnO Photocatalyst and its Photocatalytic Property

ZnO nanoparticles were modified by polyaniline (PANI) using ‘in situ’ chemical oxidative polymerization method. The morphology, structure, and light absorption properties of PANI-ZnO composites were examined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–vis spectra. UV–vis spectra reveal that PANI-ZnO composites showed stronger absorption than neat ZnO under the whole range of visible light. New characteristic peaks were found in PANI-ZnO composites according to the X-ray diffraction patterns after hybridization of PANI and ZnO, which indicating that there was a strong interaction between PANI and ZnO nanoparticles. The resulting PANI-ZnO composites exhibit significantly higher photocatalytic activity than that of neat ZnO for degradation of anthraquinone dye (reactive brilliant blue KN-R) aqueous solution under visible light irradiation (λ > 420 nm).

NaNO<sub>2</sub>/Fe<sup>3</sup><sup>+</sup>/O<sub>2</sub> System Catalyzed Wet Air Oxidation of Reactive Brilliant Blue KN-R

Subscript textThe degradation of Reactive Brilliant Blue KN-R by NaNO2/Fe3+/O2 system was evaluated. The optimal conditions of dye degradation by the NaNO2/Fe3+/O2 system were: reaction temperature 150°C, oxygen partial pressure 0.5Mpa, pH 3.0, Reactive Brilliant Blue KN-R /NaNOSubscript textSubscript text2/FeCl3 (mole ratio) equal to 1:2:0.2.Under the optimal conditions, the removal rates of color 、COD and TOC were 100% 、64% and 52%, respectively.

Diafiltration and concentration of Reactive Brilliant Blue KN-R solution by two-stage ultrafiltration process at pilot scale: Technical and economic feasibility

In this study, a two-stage ultrafiltration (UF) membrane separation process on a pilot scale was introduced to resolve the shortcomings caused by the application of salt precipitation technique in the conventional process of Reactive Brilliant Blue KN-R production. The first stage was used for diafiltration and concentration of dye solution, and the second stage was applied to recover the dye from permeate of the first stage. Both the operating pressure and cross-flow velocity had significant and moderate effect on the permeate flux (24.9 to 129.7 L·m − 2 ·h − 1 ) and salt rejection (26.9%–55.7%), but insignificant effect on dye rejection since the rejections were always higher than 99.5%. The two-stage UF membrane process exhibited good performance as the dye and salt concentrations in concentrate of first stage were 203 and 5.4 g/L, and 67.1% of salt could be removed and the dye loss was negligible (0.1%) in the whole process. For a dye plant with a capacity of 1000 ton per year, the preliminary economic evaluation of an UF plant based on pilot scale showed that the cost of every ton of Reactive Brilliant Blue KN-R was US $154.

The comparative study on the rapid decolorization of azo, anthraquinone and triphenylmethane dyes by zero-valent iron

The comparative study was carried out for the decolorization of three kinds of dyes: azo dye, Reactive Brilliant Red K-2G (RBR); anthraquinone dye, Reactive Brilliant Blue KN-R (RBB); and triphenylmethane dye, Malachite Green (MG) from aqueous solution by zero-valent iron (ZVI) as an effective reductant. ZVI was synthesized with a modified method of reduction in liquid phase, in which the macromolecule stabilizer polyvinylpyrrolidone was added. The effects of solution pH, ZVI dosage and initial dye concentration on the decolorization were investigated. The results showed that pH value had little effect on dye decolorization. With increasing dosage of ZVI, decolorization efficiency increased, but reduction capacity and reaction time showed descending trends. High decolorization efficiency (95.74–99.22%) was achieved within 2 min for 698.24 mg/L for RBR, 10 min for 691.69 mg/L for RBB and 30 min for 686.10 mg/L for MG at optimal pH. The first-order kinetic model was found to fit the experimental data well. The UV–vis spectra and FTIR spectra analysis indicated that chromophores of dyes were destroyed and some functional groups such as amino and aromatic ring were transformed in the decolorization process. ZVI was proved to be a universal and efficient reductant for rapid decolorization of the three dyes.

Photocatalytic Degradation of Reactive Brilliant Blue KN-R by N, Fe- TiO<sub>2</sub>/FFA

TiO2 photocatalyst modified by N and Fe ions was loaded on self-made fly ash forming adsorbent (FFA) using the sol-gel dip-coating process. The crystal structure and photoadsorption ability was characterized by X-ray diffraction (XRD) and UV-Vis spectrophotometer, respectively. The photo catalytic degradation of Reactive Brilliant Blue KN-R using N, Fe-TiO2/FFA was examined. Effects of initial dye concentration, pH value and hydrogen peroxide dosage on degradation were studied. The degradation of the organic molecule followed a pseudo-first-order kinetics according to the Langmuir model. Under the optimum operation conditions, 30 mg/L KN-R could be decolorized over 97.47% within 75 min.

Synthesis of visible-light responsive Sn-SnO2/C photocatalyst by simple carbothermal reduction

Sn-SnO2/C photocatalysts with visible light activity have been successfully synthesized by a simple heat-treating process using SnCl4 as precursor. The Sn-SnO2 heterojunction is built by depositing of metallic Sn on crystal lattice oxygen of as-formed SnO2, which obviously increase the amount of adsorbed oxygen on the surface of catalyst. The as-synthesized catalysts display higher photocatalytic activity than SnO2 and SnO2/C for degradation of reactive brilliant blue KN-R under visible light irradiation. The enhancement of photocatalytic performance of Sn-SnO2/C can be attributed to the formation of metallic Sn on the surface of catalysts. The metallic Sn and adsorbed oxygen as the sinks of photoinduced electron and electronic scavenges, respectively, hinder the recombination of photoexcitated electron-hole pairs, sequentially enhance the photocatalytic activity. Furthermore, a possible growth mechanism of the Sn-SnO2/C photocatalysts was proposed.

Synthesis and Application of the Cationic Lignin Amine Flocculant

Abstract Cationic lignin amine flocculants were obtained by the Mannich reaction of Kraft lignin with formaldehyde and polyamines. The cationic reaction products were tested as a flocculating agent by flocculation of reactive brilliant blue KN-R and linear alkylbenzene sulphonates in an aqueous system. The effects of flocculant dosage and pH on the flocculation performance are discussed in detail. The results indicate that under optimum conditions, the rate of eliminating reactive brilliant blue KN-R and linear alkylbenzene sulphonates from the water exceed 99% and 96% respectively, which illustrated that the cationic reaction products are extremely effective as flocculants for reactive brilliant blue KN-R and linear alkylbenzene sulphonates.

Contributions of functional groups and extracellular polymeric substances on the biosorption of dyes by aerobic granules

The contributions of loosely bound extracellular polymeric substances (LB-EPS), tightly bound EPS (TB-EPS), residual sludge (the sludge left after EPS extraction) and functional groups such as amine, carboxyl, phosphate and lipid on aerobic granules on biosorption of four different dyes (Reactive Brilliant Blue KN-R (KN-R), Congo Red (CR), Reactive Brilliant Red K-2G (RBR) and Malachite Green (MG)) were investigated. EPS may be responsible for biosorption of cationic dyes. However, residual sludge always made greater contribution than that of EPS. The biosorption mechanisms were dependent on the functional groups on aerobic granules and dyes' chemical structures. The lipid and phosphate groups might be the main binding sites for KN-R biosorption. Amine, carboxyl, phosphate and lipid were all responsible for the binding of CR. The lipid fractions played an important role for RBR biosorption. For MG, the phosphate groups gave the largest contribution.

Flocculated decolorization of vinylsulfone reactive dye solutions with a β-cyclodextrin-based copolymer

A β-cyclodextrin (β-CD)-based copolymer (β-CD–maleic anhydride–N-trimethylaminoethylmethacrylate chloride) with good thermal stability was designed and synthesized for flocculated decolorization of Reactive Brilliant Blue KN-R solutions. Jar tests indicated that with the optimal stirring mode as 120 rpm for 5 min and then 40 rpm for 5 min with a flocculant-to-dye ratio of 2 : 5 (w/w), a pH of 8–10, and a temperature of 20°C, the maximum color removal reached. It is reported first in this article that, in addition to the polymer bridge and charge neutralization, the covalent bond of the reactive dye to the target flocculant molecules, which had a similar chemical structure to that of cellulose, contributed to the mechanism of flocculated decolorization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010