Highly efficient removal of basic blue 41 with nanoporous silica

WITHDRAWN: Heavy metal ions and dyes removal from aqueous solution using Aloevera-based biosorbent: A systematic review

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Enhancement Properties of Zr Modified Porous Clay Heterostructures for Adsorption of Basic-Blue 41 Dye: Equilibrium, Regeneration, and Single Batch Design Adsorber

Zirconium porous clay heterostructures (Zr-PCH) were synthesized using intercalated clay minerals by zirconium species with different contents of zirconium. The presence of zirconium and silica species was confirmed by X-ray diffraction, X-ray fluorescence, and magic-angle spinning nuclear magnetic resonance. The insertion of zirconium improved the thermal stability, the specific surface area with a maximum of 950 m²/g, and the acidity concentration of 0.993 mol of protons per g of solid. These materials were used to adsorb the basic blue-41 from aqueous solution. The adsorption efficiency was examined at different conditions, with a maximum adsorbed amount of 346 mg/g as estimated from Langmuir model. This value was dependent on zirconium content in the PCHs. The adsorption process was found to be favorable and spontaneous. The efficiency of the spent materials was maintained after five reuse cycles with a decrease by 15% of the original value for a particular Zr-PCH material with a Zr content of 6.82%. Single stage batch adsorber was suggested using the mass balance equation and Langmuir isotherm model. The amount of PCH materials required depended on the target percentage of adsorption at specific volume and initial concentration of the basic-blue-41 dye solution.

Amine-amide functionalized graphene oxide sheets as bifunctional adsorbent for the removal of polar organic pollutants

Effective mitigation of polar organic impurities from industrial effluents is a global environmental challenge. Here, we describe the solvothermal synthesis of ammonia-functionalized graphene oxide (NH₃GO) sheets for adsorptive removal of diverse organic pollutants, such as cationic dye basic blue 41 (BB41), anionic dye methyl orange (MO), and ionic 4-nitrophenol (4-NP), in aqueous media. Structural analysis of NH₃GO suggest a potent role of surface acidic and basic binding sites in adsorption of targets through an interplay of dynamic experimental variables, e.g., contact time, pH, initial adsorbate concentration, adsorbent mass, and temperature. At an initial pollutant concentration of 20 mg/L, equilibrium adsorption capacities for BB41, MO, and 4-NP were estimated at 199.5, 64.0, and 54.1 mg/g, respectively, with corresponding partition coefficients of 4156, 79.4, and 14.3 L/g, respectively. Experimental data of all three organic pollutants are best fitted by the pseudo-second-order kinetic model. The adsorption isotherm of BB41 follows a multilayer adsorption pattern, while those of MO and 4-NP fit into a monolayer adsorption pattern. The endothermic and spontaneous nature of the adsorption processes has also been explored for the three targets on NH₃GO based on thermodynamic analysis. The prepared NH₃GO sheets appear to be a promising adsorbent for the removal of polar organic dyes and aromatics in the solution phase.

Al and Zr Porous Clay Heterostructures as Removal Agents of Basic Blue-41 Dye from an Artificially Polluted Solution: Regeneration Properties and Batch Design

The removal of Basic Blue-41 dye molecules was carried out by using two doped porous clay heterostructures by aluminum (Al) or zirconium (Zr) species. The proposed method of synthesis showed its efficiency, starting from Al or Zr intercalated hydrolyzed species, prior to its reaction with dodecylamine (C12 amine) and tetraethyl orthosilicate (TEOS) as a silica source. The intercalated precursors and their porous clay heterostructures (PCH) derivatives were characterized by different techniques. Solid NMR technique proved the presence of Al species into the intercalated silica between the clay sheets, and in addition to Si in different environments within the PCH materials. The Zr-PCH material exhibited a higher surface area and pore volume compared to its Al-PCH counterpart, with a mesoporous character for both materials. A maximum removed amount of 279 and 332 mg/g was achieved and deduced from the Langmuir equation. The regeneration tests revealed that the removal efficiency of Zr-PCH was retained after five regeneration runs, with a loss of 15% of the original value; meanwhile, the Al-PCH lost 45% of its efficiency after only three cycles. A single-stage batch design was proposed based on the Langmuir isotherm parameters. The increase of the removal capacity of Zr-PCH led to the reduction of the required amounts for the target removal of BB-41 dye compared to Al-PCH.

Hybrid Material Based on an Amorphous-Carbon Matrix and ZnO/Zn for the Solar Photocatalytic Degradation of Basic Blue 41

Innovative composites based on an amorphous-carbon matrix containing a second phase ZnO oxide and/or highly dispersed Zn metallic were synthesized via a modified Pechini route, in which a partial pyrolysis method was reached. Studies of adsorption in the dark and the photocatalytic activity for the cationic azo-dye, basic blue 41, and degradation were carried out. X-ray diffraction patterns for the carbon matrix and its composite with Zn show characteristics of the amorphous carbon. The infrared in the mid region of the composite prepared with ZnO and Zn exhibit vibrational bands related to bonds zinc oxide. The surface pH of the material is the main factor responsible for the adsorption of the azo-dye, but the contribution of mesopores favored the diffusion of molecules from the bulk of solution to the pore framework. Esters-like functional groups on the surface of carbons hinder the adsorption of the azo-dye. When Zn is embedded within amorphous carbon the photocatalytic activity of the composites showed up to 2.4 higher than neat ZnO. The enhancement in the photocatalytic activity and stability of C/ZnO/Zn and C/Zn composites is discussed in terms of a protector effect by the carbon layers inserted in composites. Carbon layers are responsible to inhibit the lixiviation of ZnO particles along irradiation.

Waste Bricks Applied as Removal Agent of Basic Blue 41 from Aqueous Solutions: Base Treatment and Their Regeneration Efficiency

Waste brick materials were applied as removal materials of basic blue 41 (BB-41) from artificially contaminated water. They were characterized by different techniques prior their use. A series of removal tests were carried out at different conditions, such as a dosage effect, pH value, initial concentrations, and chemical treatment. The removal results indicated that the two untreated waste bricks had limited removal capacities of basic blue 41, ranging from 19 to 30 mg/g. However, these values were improved upon treatment with NaOH solution or by increasing the removal temperature. Waste brick collected from the Medina area (Med-WB) exhibited higher removal capacity compared to the one collected from the Jeddah area (Jed-WB), with a maximum removal capacity of 60 mg/g at 60 °C. The pH of the BB-41 solution also played an important factor, as it improved the removal amounts from 25 mg/g to 45 mg/g at initial concentration of 200 mg/L. The regenerative process was studied using oxidative reaction of the removed basic blue 41 with a solution of oxone and cobalt nitrate. The efficiency was maintained after 5 runs for Med-WB, with a slight variation of 25%, while it felt to 50% for Jed-WB material after three runs. These data indicate that the waste brick materials present as potential candidates for the dye removal and their origin has to be identified.

Performances of Pichia kudriavzevii in decolorization, biodegradation, and detoxification of C.I. Basic Blue 41 under optimized cultural conditions

The aim of this study was to evaluate the performances of Pichia kudriavzevii CR-Y103 yeast strain for the decolorization, biodegradation, and detoxification of cationic dye C.I. Basic Blue 41, a toxic compound to aquatic life with long-lasting effects. Under optimized cultural conditions (10.0-g L^-1 glucose, 0.2-g L^-1 yeast extract, and 1.0-g L^-1 (NH₄)₂SO₄), the yeast strain was able to decolorize 97.86% of BB41 (50 mg L^-1) at pH 6 within 4 h of incubation at 30 °C under shaken conditions (12,238.00-μg h^-1 average decolorization rate) and 100% within 12 h. The UV-Vis spectral analysis, high-performance liquid chromatography (HPLC), and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the complete decolorization and degradation of the BB41 dye by P. kudriavzevii CR-Y103. Also, other seven yeast strains, isolated from soil, as P. kudriavzevii (CR-Y108, CR-Y119, and CR-Y112), Candida tropicalis CR-Y128, Cyberlindnera saturnus CR-Y125, and Candida solani CR-Y124 have shown a promising decolorizing potential of azo-dye BB41 (99.89-76.09% decolorization). Phytotoxicity, cytotoxicity, and genotoxicity assays on Trifolium pratense and Triticum aestivum seedlings confirmed the high toxicity of BB41 dye (500 ppm), with inhibition on germination rate (%), root and shoot elongation, decreasing of mitoxic index value (with 34.03% in T. pratense and 40.25% in T. aestivum), and increasing the frequency of chromosomal aberrations (6.87 times in T. pratense and 6.25 times in T. aestivum), compared to control. The same biomarkers indicated the nontoxic nature of the BB41 degraded metabolite (500 ppm) obtained after P. kudriavzevii CR-Y103 treatment. Moreover, the healthy monkey kidney cells (Vero cells) had a low sensitivity to BB41 biodegraded products (250 μg mL^-1) (MTT cell viability assay) and revealed minor DNA damage (comet assay) compared to BB41 dye treatment. These findings show that P. kudriavzevii could be used in eco-friendly bioremediation technologies, applicable for reducing the toxicity of basic azo-dyes containing wastewaters.

Adsorption-desorption behavior of magnetic amine/Fe3O4 functionalized biopolymer resin towards anionic dyes from wastewater

In this work, a new kind of magnetic amine/Fe3O4 functionalized biopolymer resin (amine/Fe3O4-resin) was prepared and applied to remove various anionic dyes from water. Methyl Orange (MO), Reactive Brilliant Red K-2BP (RBR) and Acid Red 18 (AR) were selected as the typical anionic dye for this research. Meanwhile, amine/Fe3O4-resin was characterized by VSM, XRD, FT-IR, SEM, TEM and XPS. Three anionic dyes removed by amine/Fe3O4-resin were investigated using batch adsorption technique, and the parameters including adsorbent dosage, pH, contact time and temperature were considered. Due to a large number of amine groups and high surface areas, amine/Fe3O4-resin exhibited a remarkably high adsorption capacity for all three dyes, reaching 101.0mg/g, 222.2mg/g and 99.4mg/g for RBR, MO and AR at 25°C, respectively. The pseudo second order model and Langmuir model agreed well with the experimental data, and regeneration experiments indicated its merit of separability and reusability.