Direct Blue 15 Research Articles

Perovskite lanthanum aluminate nanoparticles applications in antimicrobial activity, adsorptive removal of Direct Blue 53 dye and fluoride

In the present study, efficient adsorptive removal of fluoride and Direct Blue 53 (DB-53) dye solution on perovskite lanthanum aluminate (PLA) has been investigated. To characterize the prepared PLA with analytical techniques like FTIR, SEM, EDS, PXRD, PHZPC and BET. The influence of adsorbent dose (0.05–0.6) gL−1, pH (2−12), contact time (0–60 min) and initial adsorbate concentration (0–50 mg L−1) were studied on adsorption process. Mathematical modeling of kinetics and isotherms were computed using equations. The pseudo-second-order kinetic and Halsey isotherm equilibrium model are best fitted with experimentally computed data with R2 > 0.96. The value of free mean energy EDR per adsorbate molecule was 1.77 kJmol−1 (fluoride) and 1.86 kJmol−1 (DB-53) with an adsorption capacity 25.103 and 38.03 respectively, hence nature of adsorption suggested as physisorption process. The maximum Langmuir adsorption capacity of PLA was investigated to be 40.8 mgg−1 (fluoride) and 71.4 mgg−1 (DB-53). Present study PLA deficits efficient adsorbent for fluoride and DB-53 dye for ground and industrial wastewater. Further, the effect of in-vitro antimicrobial studies was carried out against six test microorganisms. PLA showed, a maximum antibacterial effect at MIC 63 μg mL−1 for Gram-negative bacteria: Pseudomonas aeruginosa (NCIM 5029) due to the interaction between the positively charged nanoparticle and negatively charged cell wall.

Degradation of printing and dyeing wastewater by modified biochar catalyzed persulfate

The biochar (BC) obtained from banana peel was used to catalyze persulfate (PS) to degrade the Direct Blue 86 (DB86) simulating and dyeing wastewater, which can obtain a much better degradation efficiency (71.1% within 1440 min) compared with BC (insignificant) or PS (26.7%) alone. Then BC was modified, and the influence of modified method, PS concentration, biochar content and temperature on DB86 degradation was also investigated. Results showed that the acid modified method of BC had advantage for the DB86 degradation, and 99% decolorization efficiency can reach within 240 min. The degradation of DB86 increased with PS concentration increasing, and then decreased slowly. Increasing the acid modified BC dosage and temperature can improve effectively the DB86 degradation. When the experimental conditions are PS 5×10-3 M, acid modified BC 5.0 g/L, and 25°C, the degradation of DB86 can reach 99% within 60 min.

Synthesis, characterization of visible active MO hallow spheres by combustion technique


 
 
 A simple method to synthesize nano-sized hallow sphere such as Zn-Ce metal oxide (MO) by combustion technique. The product was characterized by X-ray diffraction (XRD), Field emission-scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), Thermo gravimetric analysis (TGA), Diffuse Reflectance Spectroscopy (DRS) and Transmission electron microscope (TEM). The photocatalytic activity of Zn-Ce MO nano-sized hallow sphere was examined by studying the degradation of direct blue 71 (DB71) under visible light irradiations in a slurry photoreactor. The effect of parameters such as the catalyst dosage, concentration of the dye, pH and kinetics on photocatalytic degradation of DB71 is also studied. Degradation of dye was confirmed by UV-VIS spectrum, chemical oxygen demand (COD) and ESI-Mass.
 
 

Classification of pre-dyed textile fibers exposed to weathering and photodegradation by non-destructive excitation-emission fluorescence spectroscopy paired with discriminant unfolded-partial least squares

Undyed textile fabrics such as Acrylic 864, Nylon 361 and Cotton 400 were pre-dyed with Basic Green 4 (BG4), Acid Yellow 17 (AY17) and Direct Blue 1 (DB1) dyes, respectively; and then exposed to two extremely diverse weather conditions in the United States: desert and humid environmental settings in Arizona (AZ) and Florida (FL) respectively, for different time intervals of exposure, which included 0, 3, 6, 9 and 12 months. After every interval of a 3 months period, ten fibers were uniformly sampled from each cloth piece, and fluorescence microscopy was employed to collect two-dimensional excitation and fluorescence spectra (2-D spectra) and three-dimensional (3D) excitation-emission matrices (EEMs). A significant loss of fluorescence intensity was observed upon fiber exposure to outdoor weathering conditions. For a comprehensive statistical data analysis and to be able to discriminate between any two single fibers weathered under different conditions, a multiway calibration algorithm known as discriminant unfolded partial least-squares (DU-PLS) method was applied to the exposed fibers. Results indicate that fluorescence spectroscopy combined with DU-PLS has the ability to appropriately classify and differentiate between any two pairs of dyed cotton or nylon fibers (acrylic in some cases) exposed to dry versus humid weather environments under different time intervals of exposure. These results provide the foundation for future studies towards a non-destructive approach capable to provide information on the weathering history of the fiber.

Optimization of Direct Blue-14 dye degradation by Bacillus fermus (Kx898362) an alkaliphilic plant endophyte and assessment of degraded metabolite toxicity.

Alkaliphilic bacteria possesses the ability to survive in the extreme conditions with high salt concentrations. The adaptability of alkaliphilic bacteria to extreme conditions has made them predominant degrader in the field of biodegradation. A moderately alkaliphilic endophyte was isolated from Centella asiatica with a potential to degrade a di-azo dye Direct Blue-14(DB-14). The isolate was identified as Bacillus fermus with 97% similarity strain Xmb064. On optimization, maximum of 92.76% biodegradation was attained with dye concentration at 68.78 ppm supplemented with 1 g of sucrose and 2.5% (v/v) of inoculum for 72 h incubation. Characterization of the biodegraded product carried out using UV-vis spectrophotometry, FT-IR and LC-MS confirmed the destabilization of di-azo bond followed with the degradation of DB-14. Cytogenotoxicity studies revealed the biodegraded products to be less toxic. The current study is the first report on the optimization, biotransformation and cytogenotoxicity of DB-14 by B. fermus strain Centella.

Amino grafted MCM-41 as highly efficient and reversible ecofriendly adsorbent material for the Direct Blue removal from wastewater

The very high adsorption efficiency of Direct Blue (DB), an anionic toxic azo dye, onto amino grafted mesoporous silica nanoparticles (MCM-41), was studied in this paper, for possible industrial applications. Interesting challenges and advances are proposed in this field, presenting an adsorbent able to efficiently and rapidly remove the anionic dye from water. The important added value of this work regards the system recycle, which allows both the DB and adsorbent material recover, with a global reduction of the environmental impact, in the viewpoint of the green economy. Indeed, this paper is the first example of very fast removal and recycle of great amounts of DB with adsorbent materials characterized by impressive adsorption/desorption capacities, at least of around 300 mg/g for each adsorption cycle, potentially increasable by performing consecutive cycles of DB adsorption/desorption. In detail, the MCM-41 amino functionalization (MCM-41-NH2) was obtained after (MCM-41-POST) and during (MCM-41-PRE) the synthesis of MCM-41, obtaining materials with different behavior towards the DB adsorption. The MCM-41-NH2 surface features and porous structure, before and after the dye adsorption, were carefully characterized. Considering the adsorption process, for investigating the nature of the DB/MCM-41-NH2 interaction, several parameters were studied: the contact time, the DB solutions pH values, adsorbent material and dye amount, with the additional analysis of how the adsorption process was influenced by the presence of electrolytes. The isotherms of adsorption were also considered. Although MCM-41-PRE exhibited a higher affinity towards DB molecules, the MCM-41-POST were able to rapidly desorb it, thus recycling both DB and the adsorbent material.

Enzymatic detoxification of azo dyes by a multifarious Bacillus sp. strain MR-1/2-bearing plant growth-promoting characteristics.

This study was conducted to elucidate the inherent potential of Bacillus sp. MR-1/2, which was isolated from root zone of maize crop grown on a textile wastewater-irrigated soil. The isolated strain was identified through its ribosomal RNA sequence. Under in vitro conditions, the strain demonstrated its tolerance for high concentrations of various heavy metal ions as determined by minimum inhibitory concentration. Moreover, the strain MR-1/2 exhibited many important phytobeneficial traits such as inorganic P solubilization and 1-aminocyclopropane-1-carboxylate (ACC) deaminase ability even under high metal and salt stress. Results showed that the strain proficiently decolorizes various azo dye compounds, e.g., reactive black-5, reactive red-120, and direct blue-1 and congo red, in broth culture. The bioremediation potential of the strain MR-1/2 was further confirmed by analyzing the retrieved azoreductase gene sequence through bioinformatics tools, whereby a subsequent prediction revealed that the azoreductase enzyme activity was involved in decolorization process. When mung bean seeds were grown in pots under various concentrations of decolorized and non-decolorized azo dye, the Bacillus sp. MR-1/2 not only alleviated the azo dye toxicity, but also increased the plant growth parameters. In conclusion, the strain MR-1/2 efficiently decolorized the azo dyes and helped in mung bean plant growth by alleviating azo dye toxicity.

Preparation of CTAB-functionalized aqai stalk and its efficient application as adsorbent for the removal of Direct Blue 15 and Direct Red 23 dyes from aqueous media

ABSTRACTIn this work, a new adsorbent material based on the chemical modification of aqai stalk (AS) with hexadecyltrimethylammonium bromide (CTAB) was proposed, forming a new material called AS-CTAB. The characterization data from the AS-CTAB adsorbent indicated that the biomass was chemically modified by the surfactant. The prepared material was successfully used as an adsorbent for the removal of Direct Blue 15 (DB-15) and Direct Red 23 (DR-23) from aqueous solutions. For both dyes, adsorption followed the Avrami kinetic model. The kinetic data were better fitted using the nonlinear Avrami fractional model for both dyes. The contact time between the adsorbent and adsorbate was fixed at 180 and 30 min for DB-15 and DR-23, respectively. This remarkable difference of contact time between the dyes with AS-CTAB adsorbent was attributed to the difference in the physicochemical characteristics of the dyes such as size of the molecule, hydrophilic–lipophilic balance, and polar surface area (PA). The Liu isotherm model displayed Qmax of 394.2 and 454.9 mg g−1 for DB-15 and DR-23, respectively, at 45°C. Since the AS-CTAB is not a porous material, electrostatic interaction was the main mechanism involved in the adsorption process for both dyes. The thermodynamic adsorption reaction was shown to be a spontaneous and endothermic process. The AS-CTAB adsorbent was also tested in the treatment of synthetic dye effluents and presented a removal of up to 95.41% of a simulated effluent containing several dyes and high saline concentration.

Highly Efficient and Sustainable Spent Mushroom Waste Adsorbent Based on Surfactant Modification for the Removal of Toxic Dyes.

The treatment of wastewater always demands eco-friendly and cost-efficient adsorbents. In this paper, spent mushroom waste (SMW) was modified by a cationic surfactant (cetyltrimethylammonium bromide, CTAB) to eliminate toxic dyes. A characterization of adsorbents confirmed that CTAB was successfully embedded into the SMW structure. The spent mushroom waste, modified by CTAB (SMWC), exhibited an excellent adsorption capacity of 249.57 mg·g−1, 338.67 mg·g−1, and 265.01 mg·g−1 for the Direct red 5B (DR5B), Direct blue 71 (DB71), and Reactive black (RB5) dyes, respectively. Batch experiments indicated that the dye adsorption of SMWC depended mainly on pH, dye concentration, temperature, and ionic strength. The adsorption isotherm could be fitted to the Langmuir model and described by the pseudo-second-order kinetic model. The dye adsorption mechanism was dominated mostly by the chemosorption of the dyes and the SMWC surface. Thermodynamic parameters showed that the adsorption was endothermic and spontaneous. SMWC could successfully remove over 90% of dyes from various water samples. This can be considered a feasible waste resource utility, since it meets both the ecological and the economic requirements for auspicious industrial applications.

Efficiency of Multi Walled Carbon Nanotubes for Removing Direct Blue 71 from Aqueous Solutions

Dye wastewater produced from industrial activity is usually toxic, resistant to biodegradation and persistent in the environment. The aim of this study was to evaluate the efficiency of multiwalled carbon nanotubes (MWCNTs) for decolorization of Direct Blue 71 (DB71). In this experimental study, the effect of various variables including contact time, solution pH, adsorbent dose, and initial dye concentration was evaluated in a batch reactor. The adsorption and kinetic models were evaluated to explain the adsorbed dye and dynamic reaction. The results of this study showed that the efficiency of dye removal increased, as the contact time and adsorbent dose increased, but as pH and initial dye concentration increased, removal efficiency decreased. The maximum efficiency of Direct Blue 71 removal was observed at acidic solution (pH=3), contact time of 90 minutes, adsorbent dose of 0.6 g/l and initial dye concentration of 25 mg/l. The adsorption of direct blue 71 best fitted the Langmuir isotherm (R2=0.87) and pseudo first order kinetic equation (R2=0.99). According to the results obtained, multiwalled nanotubes was offered as an effective adsorbent for removing direct blue 71. © Authors.

Enhanced Photocatalytic Degradation of Direct Blue-1 Dye by Zno Nanoparticles Using Visible Light

Enhanced Photocatalytic Degradation of Direct Blue-1 Dye by Zno Nanoparticles Using Visible Light

Decolorization of a variety of dyes by Aspergillus flavus A5p1.

Aspergillus flavus: fungal strain A5p1 is reported here to decolorize a variety of dyes under broad environmental conditions. For the 15 dyes tested, the decolorization efficiencies ranged from 61.7 to 100.0% at an initial concentration of 100mg/L. Direct Blue 71 (DB71), Direct Blue 86 (DB86), and Reactive Blue 19 (RB19) were selected as models for comparing decolorization performance. The results show that biosorption and biodegradation work together in the strain to remove the pigments; the effect of biosorption was stronger for DB71 and DB86, whereas the effect of biodegradation was stronger for RB19. For DB71 and DB86, the decolorization rate surpassed 90% with inactivated biomass under acidic conditions and with living biomass under alkaline conditions. DB19 achieved the highest removal rate of 90% under neutral conditions. The strain could effectively decolorize high concentrations of dyes up to 1000mg/L, which was achieved mainly via biosorption at concentrations below 500mg/L and via biodegradation at concentrations above 500mg/L. The findings suggest that A5p1 has a strong adaptability to different dye types and environmental conditions and can, therefore, be potentially used in biological processes for the treatment of dye-containing wastewater.

Biodegradation mechanism of direct blue 15 (DB15) and effect of NaCl on the removal efficiency in anoxic/oxic SBR system with synthetic textile wastewater containing DB15 (STWW+DB15)

Biodegradation mechanism of direct blue 15 (DB15) and effect of NaCl on the removal efficiency in anoxic/oxic SBR system with synthetic textile wastewater containing DB15 (STWW+DB15)

Effective Removal of Hazardous Dyes from Aqueous Solutions Using Starch Based Hydrogel and Gamma Radiation

The adsorption performance of acrylamide/ starch hydrogel (AAm/starch) prepared by gamma radiation for removal of direct congo red (DCR) and direct blue (DB) dyes has been investigated. The physico-chemical parameters such as dye concentration, solution pH and temperature have been studied. Favorable adsorption occurred at pH 3 for DCR and pH 10 for DB. The adsorption of dyes onto AAm/starch hydrogels was endothermic process. Experimental data have been modeled by the Freundlich isotherm. Degradation test of DCR and DB dyes using gamma irradiation in aqueous solution under various radiation doses and pH was investigated and G-value was calculated. Destruction of 70% and 75% of the dye colour solutions was succeeded at radiation dose 40 and 30 kGy for DCR and DB, respectively. Comparing the removal percent of DCR and DB dyes by radiation degradation with that done by AAm/starch hydrogel adsorption was investigated. It was found that preferring removal of DCR and DB dyes by gamma radiation degradation. The remaining concentration of dyes was followed by adsorption onto the hydrogel. Complete removal of DCR and DB was performed by gamma radiation degradation followed by AAm/starch hydrogel adsorption.

Direct dye removal by using UV/hydrogen peroxide/multiwalled carbon nanotubes

In this study, decoloration of Direct Blue 71 (DB71) and Direct Red 23 (DR23) has been discussed by using Multiwalled Carbon Nanotubes (MWCNTs) and Hydrogen peroxide under UV radiation. The purpose of this study is removal of organic compounds by using carbon nanotubes that are effective adsorbents for different types of pollutants, due to their porous nature and large surface area. It also causes catalytic decomposition of hydrogen peroxide. Adsorption rate was investigated under various parameters (initial dye concentration, salt, temperature and pH). The main objective of this study is to appraise the synergic effect between H2O2 and MWCNTs under UV radiation. The dye adsorption results of spectrophotometer, showed that by decreasing the dye concentration from 0.2 g/l to 0.05 g/l with the optimal value of MWCNTs 0.2 g/l and hydrogen peroxide 2 g/l at pH=4 and 6 cm distance from the UV lamp, the dye removal increased.

Fabrication of NiFe2O4 magnetic nanoparticles loaded on activated carbon as novel nanoadsorbent for Direct Red 31 and Direct Blue 78 adsorption

ABSTRACTIn this research, magnetic nickel ferrite NiFe2O4/hazelnut-shell-based activated carbon (NiFe2O4/AC) was used to eliminate anionic dyes (Direct Red 31(DR31) and Direct Blue 78 (DB78)) from aqueous solution. The morphological, structural, particle size and surface charge properties of as-prepared nanoadsorbent were characterized. TEM (Transmission electron microscopy) images revealed that the size of NiFe2O4 particles in the structure of AC was in the range of 8-12 nm, which is compatible with the results obtained by the analysis of DLS (Dynamic light scattering). The results of the BET (Brunauer–Emmett–Teller) analysis indicated that the surface area, the pore volume and average pore diameters of the NiFe2O4 were 288 m2/g, 0.3338 cm3/g and 5.05nm, respectively. The as-prepared nanocomposite showed excellent adsorption capacity for DR31 and DB78 dyes with the highest adsorption capacity obtained at pH=2.0 and rapid dye adsorption equilibrium attained after 20 and 25 min for DR31 and DB78, respectively. The equilibrium study showed the maximum adsorption capacity (qmax) of 299.67 mg/g and 209.13 mg/g for DR31 and DB78, respectively. In addition, thermodynamic study revealed the endothermic and spontaneous nature of adsorption process. The adsorption of DR31 and DB78 onto the NiFe2O4/AC is a physisorption process, during which electrostatic adsorption was the main driving force.

Ultrasound and UV Stimulated Heterogeneous Catalytic Oxidation of an Azo Dye: A Synergistic Effect

This research deals with the decolourisation of direct azo dye, Direct Blue 71 (DB71), in aqueous solution by means of sonocatalytic, photocatalytic and sonophotocatalytic heterogeneous oxidation processes in the presence of a zinc oxide (ZnO) catalyst. The effect of these oxidation processes under visible light and 20 kHz ultrasound was investigated to study their influence on degradation rates by varying the initial dye concentration, pH and catalyst load and to understand the effect of synergy on the degradation process. The synergistic effect is quantified in terms of a synergy factor which has already been defined in the literature. The highest value of the factor was obtained for a low DB71 dye concentration at pH 5.5, 20 °C temperature and 400 mg L−1 optimum ZnO dosage. Pseudo first-order kinetics were followed for the removal of the azo dye according to the Langmuir–Hinshelwood model. For comparison, the Langmuir–Hinshelwood model was also used for experimental values obtained from the sonocatalytic process, the photocatalytic process and the combination of these processes. The Langmuir–Hinshelwood kinetic model demonstrated consistency in all calculations of the initial rates of degradation with the appropriate values for the reaction rate constant and DB71 dye absorption constant.

Valorization of Crataegus azarolus stones for the removal of textile anionic dye by central composite rotatable design using cubic model: optimization, isotherm, and kinetic studies.

In this study, the central composite rotatable design (CCRD) was used in the optimization of the operating parameters for the removal of the direct blue 86 (DB86), an anionic dye, because of its hazardous impact on human health and aquatic environment. In addition, DB86 is a recalcitrant and non-biodegradable dye whose presence considerably inhibits photosynthesis. Its removal in aqueous medium was achieved by biosorption onto the novel biosorbent Crataegus azarolus stones (CAS). The parameters like the solution pH, biosorbent dose, initial DB86 concentration, and temperature were studied in the ranges 2-6, 0.8-4gL-1, 20-100mgL-1, and 10-50°C, respectively. The significance of the experimental parameters and their interactions was investigated by the Student's t test and p values with 5% error limits using JMP 11.0.0 software. The regression analysis of the experimental data obtained from 31 batch runs provides a cubic model. The optimum conditions obtained for the maximum DB86 elimination from the synthetic solution were found to be pH2, biosorbent dose of 4gL-1, initial DB86 concentration of 20mgL-1, and temperature of 10°C, leading to a theoretical maximum removal of 123%. The experimental data were analyzed by the Langmuir, Freundlich, and Temkin equilibrium models. The Langmuir isotherm gave the best fit with a maximum biosorption capacity of 24.02mgg-1. The results of the kinetic study revealed that the biosorption kinetic of DB86 follows a pseudo-second-order model. All results confirmed that CAS are an efficient, economic, and ecological alternative for the treatment of industrial wastewaters loaded with anionic dyes.

Sonochemical synthesis of Sm-doped ZnS nanoparticles for photocatalytic degradation of Direct Blue 14: Experimental design by response surface methodology and development of a kinetics model

In this research, a facile and swift method was presented to synthesize pure and samarium (Sm)-doped zinc sulfide (ZnS) nanoparticles by ultrasonic probe. The synthesized samples were characterized by XRF, DRS, XRD, and FE-SEM. The prepared samples have a cubic zinc blende ZnS phase with nanoscale particles and uniform morphology. The photocatalytic activity of the synthesized samples was evaluated through the degradation of Direct Blue 14 (DB14) under UV light irradiation. The 5% Sm-doped ZnS nanoparticles revealed a higher photocatalytic performance than the pure ZnS and other Sm-doped ZnS nanoparticles. The impact of operational factors on the removal efficiency of dye was investigated by response surface methodology (RSM). The optimum conditions for photocatalytic degradation of DB14 (86.36%) were found to be 10mgL−1 of DB14, 0.8gL−1 of 5% Sm-doped ZnS, at pH=3.5, and an irradiation time of 48min. A kinetics modeling of the process was also proposed, based on the Langmuir–Hinshelwood mechanism, and an empirical equation was obtained for the estimation of apparent pseudo first-order rate constant (kap) as a function of operational factors. Finally, byproducts resulting from the photocatalytic degradation of DB14 were identified using the GC–MS technique.

Dye removal from wastewater by the cross‐linked blend nanofiber and homogenous surface diffusion modeling

In this paper, the blend nanofiber (poly(vinyl alcohol) (PVA)/chitosan (CS)/diethylenetriamine (DETA)/ethylenediamine (EDA): PVA/CS/DETA/EDA) was prepared by electrospinning and cross‐linked by glutaraldehyde. The cross‐linked blend nanofiber by glutaraldehyde (CBNG) was characterized by FTIR and SEM. The homogenous surface diffusion model (HSDM) was used for expressing the dye adsorption on CBNG from colored wastewater. Experimental data were used to calculate the isotherm parameters as well as the kinetic parameters describing mass transfer resistances due to film diffusion (kf) and diffusion coefficient (Ds). The sum square error (SSE) values for the adsorption of Acid Red 18 (AR18), Direct Blue 78 (DB78), and Direct Red 23 (DR23) were 0.0221, 0.0632, and 0.0038, respectively. Thus, the experimental and theoretical data showed a good agreement. Dye removal by CBNG followed the Langmuir isotherm and pseudo‐second order kinetics models. Thermodynamic studies indicated dye adsorption onto the nanofiber was an endothermic, spontaneous, and physisorption process. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1634–1642, 2017