Showing papers on "Brilliant green published in 2019"

Removal of hazardous basic dyes from aqueous solution by adsorption onto kaolinite and acid-treated kaolinite: kinetics, isotherm and mechanistic study

Abstract: Presence of dye molecules in water causes various harmful effects for both human and aquatic species. Herein, we tried to remove two cationic dyes, namely Crystal violet and Brilliant green, from water by kaolinite clay mineral. The kaolinite clay mineral is further treated with 0.25 M and 0.05 M H2SO4 to increase its adsorption capacity. The structural changes due to acid treatment were analyzed by XRD, zeta potential, FTIR, SEM, cation exchange capacity, BET surface area, and pore volume measurements. Kinetic data were analyzed by using five different kinetic models and the data fitted best to pseudo-second-order model. Langmuir isotherm showed best fit to the adsorption of both Crystal violet and Brilliant green. Acid–treatment has slightly increased the adsorption capacities for both the dyes. The Langmuir monolayer adsorption capacity of raw kaolinite was found to be 47.17 and 25.70 mg g−1 for Crystal violet and Brilliant green, respectively, which increased to 49.50 and 50.51 mg g−1 for 0.25 M and 0.50 M acid-treated kaolinite in case of Crystal violet and to 26.45 and 26.88 mg g−1 in case of Brilliant green at 303 K. Crystal violet adsorption was exothermic with increase in ∆G values, whereas Brilliant green adsorption was endothermic in nature with decrease in ∆G in the temperature range 293–323 K. Reusability study showed the adsorbents could be successfully used up to 3rd cycle without much loss of adsorption capacity.

The Removal of Brilliant Green Dye from Aqueous Solution Using Nano Hydroxyapatite/Chitosan Composite as a Sorbent.

Abstract: Nanocomposites of natural bone that show some benefits in terms of both composition and microstructure were synthesized by an in situ precipitation method. Hydroxyapatite (Hap) was prepared from cost-effective precursors within chitosan (CS) dissolved in aqueous acetic acid solution. The nanocomposite was synthesized for the removal of brilliant green dye (BG) from a contaminated water solution. The compositional and morphological properties of the nanocomposite were studied by means of FTIR spectroscopy, X-ray diffraction (XRD), SEM, and TEM analysis. Batch experiments were carried out to investigate the effects of pH, contact time, and initial concentration, as well as the adsorbent dosage and zero point charge for the sorbent to determine a suitable medium for the adsorption process. The sorption models using Mories-Weber, Lagrange, and Bangham equations were used to identify the mechanism and reaction order. The isotherm model was carried out using Langmuir, Freundlich, and Dubinin-Radusekevisch-Kanager equations to calculate the adsorption capacity and type of adsorption. Thermodynamic parameters, enthalpy change (∆Ho), entropy change (∆So), and Gibbs free energy (∆Go) were evaluated. All of the results suggest the feasibility of using nanocomposites as a sorbent for brilliant green dye removal.

Preparation of Magnetic Fe₃O₄/MIL-88A Nanocomposite and Its Adsorption Properties for Bromophenol Blue Dye in Aqueous Solution.

Abstract: Metal-organic frameworks (MOFs) are considered as good materials for the adsorption of many environmental pollutants. In this study, magnetic Fe3O4/MIL-88A composite was prepared by modification of MIL-88A with magnetic nanoparticles using the coprecipitation method. The structures and magnetic property of magnetic Fe3O4/MIL-88A composite were characterized and the adsorption behavior and mechanism for Bromophenol Blue (BPB) were evaluated. The results showed that magnetic Fe3O4/MIL-88A composite maintained a hexagonal rod-like structure and has good magnetic responsibility for magnetic separation (the maximum saturation magnetization was 49.8 emu/g). Moreover, the maximum adsorption amount of Fe3O4/MIL-88A composite for BPB was 167.2 mg/g and could maintain 94% of the initial adsorption amount after five cycles. The pseudo-second order kinetics and Langmuir isotherm models mostly fitted to the adsorption for BPB suggesting that chemisorption is the rate-limiting step for this monomolecular-layer adsorption. The adsorption capacity for another eight dyes (Bromocresol Green, Brilliant Green, Brilliant Crocein, Amaranth, Fuchsin Basic, Safranine T, Malachite Green and Methyl Red) were also conducted and the magnetic Fe3O4/MIL-88A composite showed good adsorption for dyes with sulfonyl groups. In conclusion, magnetic Fe3O4/MIL-88A composite could be a promising adsorbent and shows great potential for the removal of anionic dyes containing sulfonyl groups.

Removal of Brilliant Green dye from water by modified Bambusa Tulda : adsorption isotherm, kinetics and thermodynamics study

Abstract: The present research is based on the removal of Brilliant Green dye from synthetic wastewater which is one of the emerging hazardous contaminant. Adsorption technology was used to remove Brilliant Green dye using sodium carbonate-treated Bambusa Tulda as bio-adsorbent to replace costly activated carbon. Initial experiment shows the best removal of Brilliant Green dye done by sodium carbonate-treated Bambusa Tulda as compared to hydrochloric acid-treated Bambusa Tulda and distilled washed Bambusa Tulda. Scanning electron microscope, Fourier transform infrared spectroscopy and energy diffractions and X-ray analysis were done to identify functional group, surface characteristic and elemental constituents of sodium carbonate-treated Bambusa Tulda. The adsorption parameters have direct influence onto sodium carbonate-treated Bambusa Tulda for Brilliant Green dye removal. Optimum removal (98%) of dye was obtained at equilibrium time 60 min at pH 7, adsorbent dose 10 g/l, rotation per minute 200 and 298 K. Experimental data were fitted into four isotherm models and Langmuir isotherm best fitted with maximum adsorption capacity = 41.67 mg/g. Kinetics rate data fit better in pseudo-second-order model. Activation energy was observed as 16.802 kJ/mole, and the adsorption was diffusion control process. The chemical oxygen demand values of Brilliant Green dye decreased from 136 to 72 mg/l after the adsorption of Brilliant Green with sodium carbonate-treated Bambusa Tulda. Thus, it can be concluded that sodium carbonate-treated Bambusa Tulda is an efficient adsorbent and an alternative to activated carbon for the removal of Brilliant Green dye from synthetic wastewater.

Pineapple Bark Performance in Dyes Adsorption: Optimization by the Central Composite Design

Abstract: This work is concerned with the study of the adsorption in aqueous medium of a three-dye mixture which contains Methylene Blue, Brilliant Green, and Congo Red on the pineapple bark. This adsorbent material has been characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The experimental design methodology, based on the response surface methodology (RSM) by the central composite design (CCD), has been applied for the optimization of the parameters, namely, the temperature, dose of the adsorbent, and pH. The yield reached 98.91% under optimal conditions (T = 30°C; adsorbent dose = 2.5 g·L−1; pH = 9.8) at an initial concentration of 20 mg·L−1.

Microwave-Assisted Catalytic Degradation of Brilliant Green by Spinel Zinc Ferrite Sheets.

Abstract: Microwave (MW)-assisted catalytic degradation, being an emerging technique, can potentially fill in the technological gap which promises on-demand, prompt, and efficient catalysis, and therefore, s...

Adsorption of Methylene Blue, Brilliant Green and Rhodamine B from Aqueous Solution Using Collagen-g-p(AA-co-NVP)/Fe 3 O 4 @SiO 2 Nanocomposite Hydrogel

Abstract: In this study, the collagen-g-poly(acrylic acid-co-N-vinylpyrrolidone)/Fe3O4@SiO2 (collagen-g-p(AA-co-NVP)/Fe3O4@SiO2) as magnetic nanocomposite hydrogel was synthesized by graft copolymerization of acrylic acid (AA) and N-vinylpyrrolidone (NVP) onto collagen in the presence of the Fe3O4@SiO2 using ammonium persulfate as a free radical initiator and bis[2-(methacryloyloxy)ethyl] phosphate as a crosslinker under ultrasound-assisted condition. The blank collagen-g-p(AA-co-NVP) hydrogel and its composite with the Fe3O4@SiO2 nanoparticles were characterized by means of FTIR, SEM-EDS, XRD, VSM and TGA methods. The effects of different parameters such as pH, dose of adsorbent and time on swelling behavior were examined. The swelling ratio of the collagen-g-p(AA-co-NVP) hydrogel increased in the presence of the Fe3O4@SiO2 nanoparticles. Adsorption behavior of magnetic nanocomposite hydrogel was investigated for the adsorption of dyes and it was found to remove about 93% for methylene blue, 96% for brilliant green and 89% for rhodamine B in 50 mg/L of dyes solutions at pH 7. Kinetic study revealed the applicability of pseudo-first-order and pseudo-second-order models for the adsorption of mentioned dyes. The adsorption isotherm was studied in 25, 35, 45 and 55 °C using Langmuir, Freundlich, Temkin and Sips models and the adsorption data were well described by Langmuir isotherm model. Negative values of ΔGo for all three dyes suggested the feasibility of dyes removal and support for spontaneous adsorption of mentioned dyes on magnetic nanocomposite hydrogel. Desorption of dyes from the dye loaded nanocomposite hydrogel was simply done in ethanol. The results indicate that the prepared magnetic nanocomposite hydrogel is an efficient adsorbent with high adsorption capacity for the aforementioned dyes.

Visible light driven degradation of brilliant green dye using titanium based ternary metal oxide photocatalyst

Abstract: We report a novel copper and cobalt impregnated titanium based ternary metal oxide nanocomposite (CuCO0.5Ti0.5O2) synthesized via simple chemical method. X-ray diffraction pattern and SAED pattern reveals the well crystallinity (R3m space group) and phase purity of the synthesized sample. TEM micrograph shows the nano size and heterostructure of the product. Nanoporous nature of the synthesized product is observed from BET analysis. The incorporation of the copper and cobalt in titanium oxide nanoparticle host modifies the band gap of the host and a broadband absorption spectrum (∼325 nm to 800 nm) of the nanocomposite is observed from the UV–Vis-NIR absorption spectroscopy analysis. Photoluminescence (PL) spectrum confirms generation of sufficient electron-hole pairs which could actively participate in photodegradation activity. Photocatalytic performance of the product has been investigated by degrading brilliant green (BG) dye, which shows excellent activity with increased catalytic material loading. The photocatalytic activity is enhanced at high pH level of the solution. Reusability experiments confirms that the catalyst material is reusable with almost same efficiency for degrading BG dye. Wavelength selective photocatalytic degradation of BG dye reveals that the CuCO0.5Ti0.5O2 nanocomposite shows the highest activity under blue-green illumination.

Cellulose/bentonite-zeolite composite adsorbent material coating for treatment of N-based antiseptic cationic dye from water

Abstract: A cost-effective Bentonite-Zeolite-Acrylic polymer-supported adsorbent coating (Ben-Zeo-Acry) has been used for removal of cationic (antiseptic) dye. The cation exchange capacity (CEC) of Ben-Zeo-Acry adsorbent was found to be 40 meq/100 g for Na+ ions. Ben-Zeo-Acry adsorbent has been characterized using Fourier Transform Infrared spectroscopy (FTIR), Brunauer-Emmet-Teller (BET) and Particle-Size Distribution (PSD) studies, Scanning Electron Microscopy-Energy Dispersive (SEM-EDX) and X-ray fluorescence (XRF) analyses. The effect of adsorbent dosages, dye concentrations, solution pH and temperatures were studied for optimal adsorption of dye. The Ben-Zeo-Acry adsorbent coating shows almost 99% brilliant green (BG) removal efficiency from aqueous medium. Adsorption isotherms studies confirm optimal adsorption of BG (90.09 mg/g) using Langmuir model. Kinetic and thermodynamic studies showed pseudo-second-order kinetics and spontaneous as well as endothermic nature of the composite coating. Based on its significant dye adsorption capacity, the Ben-Zeo-Acry adsorbent coating could be used for treatment of cationic dye from wastewater.

Synthesis of magnetite-based nanocomposites for effective removal of brilliant green dye from wastewater.

Abstract: The present study aims at evaluating the batch scale potential of cotton shell powder (CSP), Moringa oleifera leaves (ML), and magnetite-assisted composites of Moringa oleifera leaves (MLMC) and cotton shell powder (CSPMC) for the removal of brilliant green dye (BG) from synthetic wastewater. This is the first attempt to combine biosorbents with nanoparticles (NPs) for the removal of BG. The surface properties of ML, CSP, and their composites were characterized with Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). The impact of dosage of the adsorbents (1–4 g/L), initial concentrations of BG (20–320 mg/L), pH (6–12), and contact time (15–180 min) on BG removal was evaluated. The BG removal was in order of CSPMC > MLMC > CSP > ML (98.8–86.6% > 98.2–82.0% > 92.3–70.7% > 89.0–57.4%) at optimum dosage (2 g/L) and pH (8). Moreover, maximum adsorption (252.17 mg/g) was obtained with CSPMC. The experimental results showed better fit with Freundlich adsorption isotherm model and kinetic data revealed that sorption followed pseudo-second-order kinetic model. The values of Gibbs free energy and mean free energy of sorption showed that physical adsorption was involved in the removal of BG. FTIR results confirmed that –O-H, –C-OH, =C-H, –C-H, =–CH3, HC ≡ CH, C=C, –C=O, –C-N, and –C-O-C– groups were involved in the removal of BG. The results revealed that application of low-cost biosorbents combined with NPs is very effective and promising for the removal of textile dyes from wastewater.

Fabrication of Zinc Oxide/Polypyrrole Nanocomposites for Brilliant Green Removal from Aqueous Phase

Abstract: Zinc oxide/polypyrrole (ZnO/PPy) nanocomposites were fabricated by a in situ polymerization method. The structures of the nanocomposites were analyzed by X-ray diffraction, Fourier transform infrared spectra, thermogravimetric analysis and transmission electron spectroscopy. Then, the capability of ZnO/PPy on the removal of brilliant green from aqueous phase was systematically studied. The ZnO/PPy showed high adsorption capacity toward brilliant green, and a maximum adsorption capacity of 140.8 mg/g at room temperature was achieved. The adsorption kinetics demonstrated a rapid brilliant green uptake by ZnO/PPy, and the experimental data were well fitted to the pseudo-second-order model. The equilibrium data obeyed the Langmuir model. Thermodynamic parameters of $$\Delta {G}^{0}$$ and $$\Delta {H}^{0}$$ verified the spontaneous and endothermic nature of the brilliant green adsorption onto ZnO/PPy. Furthermore, the regeneration experiments revealed that ZnO/PPy could be reused for at least five times without considerable decrease in their original adsorption capacity, showing potential applications in purification of dyeing effluents.

Preparation of SnO 2 Nanoparticles with Addition of Co Ions for Photocatalytic Activity of Brilliant Green Dye Degradation

Abstract: Pure and cobalt (Co)-doped tin oxide (SnO2) nanoparticles were prepared by using a simple co-precipitation method, and the effect of doping on structural, morphological and optical properties was studied. X-ray diffraction revealed a cassiterite tetragonal SnO2 structure with the space group of P42/mnm and without crystalline phases for the samples-doped with higher concentrations. The average crystalline size was found to be between 26.4 nm and 23.1 nm. Fourier-transform infrared spectra depicted the presence of O–H, C–H and Sn–OH absorption bands. It was observed from ultraviolet–visible spectra that the optical band gap values were decreased from 3.69 eV for pure SnO2 to 3.47 eV for 7% Co-doped SnO2. The photolumenescene emission spectra showed that the defect- and emissions-related peaks and the intensity of the peaks decreased with increasing Co concentrations. The presence of tin, oxygen and Co species were found from energy dispersive x-ray spectra. The photocatalytic activities of pure and Co-doped SnO2 nanoparticles were investigated by studying the photodecomposition of brilliant green dye, an organic pollutant. The 7% Co-doped SnO2 had higher photocatalytic activity compared to the pure SnO2, and a maximum degradation efficiency of 91% has been obtained under visible light irradiation.

Sandpaper Wastes as Adsorbent for the Removal of Brilliant Green and Malachite Green Dye.

Abstract: Sandpaper wastes were used as adsorbent after pyrolysis at 500 °C and calcination at 800 °C for the removal of brilliant green and malachite green cationic dye from an aqueous solution. The effects of the pH, the adsorbent dose, the contact time, and the initial dye concentration on the removal efficiencies were investigated. The isotherm studies were conducted by using the Langmuir, Freundlich, and Dubinin-Radushkevich models, and thermodynamic studies were also performed. The adsorption of the Brilliant green and malachite green were found to comply with the Langmuir isotherm model and the Freundlich isotherm model, respectively. The thermodynamic studies showed that the adsorption of dyes were endothermic. The E values obtained from the Dubinin-Radushkevich isotherm showed that the adsorption mechanism was chemical in nature. Furthermore, the three kinetic models (pseudo first-order, pseudo second-order, and intraparticle diffusion) were investigated. It was found that the pseudo second-order kinetic model fitted well for adsorption of dyes.

Brilliant Green and Acid Orange 74 Dyes Removal from Water by Pinus roxburghii Leaves in Naturally Benign Way: An Application of Green Chemistry

Abstract: The purpose of this study was to use low cost and easily accessible biosorbent for batch-scale elimination of brilliant green and acid orange 74 dyes from aqueous solution. Pinus roxburghii leaves were utilized to study their dye-eliminating capacities. The adsorbent was characterized by FTIR, TGA, DTA, and SEM. The optimized conditions for brilliant green and acid orange 74 dye elimination were adsorbent dose, 1.2 and 1.8 g; contact time, 30 and 45 min; pH, 2 and 1; temperature, 50°C and 60°C; and agitation speed, 125 rpm and 50 rpm for BG and AO-74, respectively. Adsorption records well fitted Langmuir isotherm. Possibility of the procedure was shown by negative values of the thermodynamic parameter ∆G° for both dyes. Kinetic studies showed that adsorption of BG and AO-74 dyes from watery solution by PR leaves followed pseudo-second-order kinetics.

Synthesis of Poly(AN-co-VP)/Zeolite Composite and Its Application for the Removal of Brilliant Green by Adsorption Process: Kinetics, Isotherms, and Experimental Design

Abstract: In this study, a poly(acrylonitrile-co-N-vinyl pyrrolidone)/zeolite (poly(AN-co-VP)/zeolite) composite was synthesized by in situ free radical polymerization (FRP). The structural properties of the composite were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The characterization results indicated that the composite had a homogeneous and 3-dimensional (3D) structure. The decomposition temperature and glass transition temperature ( ) were found as 410°C and 152°C, respectively. A poly(AN-co-VP)/zeolite composite was used to investigate the adsorption of brilliant green (BG) which is a water-soluble cationic dye. The kinetics, isotherms, and thermodynamics of adsorption were examined, and results showed that equilibrium data fitted the Langmuir isotherm model, and the adsorption kinetics of BG followed pseudo-second-order model. According to the thermodynamic properties, the adsorption process was endothermic and spontaneous. Response surface methodology (RSM), which was improved by the application of the quadratic model associated with the central composite design, was employed for the optimization of the study conditions such as adsorbent mass, time, and initial dye concentration. The RSM indicated that maximum BG removal (99.91%) was achieved at the adsorbent mass of 0.20 g/50 mL, an initial BG concentration of 40.20 mg/L, and a contact time of 121.60 minutes.

Surface Modification of Spinel Ferrite with Biopolymer for Adsorption of Cationic and Anionic Dyes in Single and Ternary Dye System

Abstract: In this work, nano cobalt ferrite was modified with biopolymer sodium alginate in alginic form and the prepared magnetic composite (CoFN-Alg) was examined by different techniques such as Fourier transform infrared spectroscopy, transmission electron microscope with energy dispersive spectra, X-ray diffraction, thermo-gravimetric analysis, and Brunauer-Emmett-Teller equation. The CoFN-Alg composite was used as adsorbent to remove Congo red (CR), brilliant green (BG), and methylene blue (MB) dyes from single and ternary dye systems. The adsorption of different dyes on CoFN-Alg composite was studied at varying parameters such as contact time, varying pH, adsorbent dose, and initial concentration at different temperatures through batch mode. Results of kinetic studies revealed that the adsorption data of different dyes in single system as well as ternary system was best fitted in Lagergren pseudo second order model. Similarly, the adsorption equilibrium data was well correlated by Langmuir isotherm model in both types of dye systems. In single system, the maximum adsorption capacities of CR, BG, and MB dyes for CoFN-Alg composite were 93.0, 92.1, 95.8 mg/g and for ternary system were 60.0, 64.4, and 76.9 mg/g, respectively. The calculated adsorption thermodynamic parameters confirmed that adsorption process was spontaneous in nature. The results of regeneration studies concluded that CoFN-Alg composite retained around 78% regeneration efficiency even after five successive cycles in single as well as ternary system. The present study revealed that CoFN-Alg composite might be suitable alternative for the removal of different dyes in single as well as multi-component system.

Nanohybrid Layered Double Hydroxides Used to Remove Several Dyes from Water

Abstract: For the preparation and characterization of several layer double hydroxides (LDH) with inorganic interlayer anions (carbonate and nitrate) and nanohybrids, two organo-LDHs were studied in detail. The dodecylbenzene sulfonate (DBS) was used as an organic interlayer anion to modify the hydrophilic nature of the interlayer. The aim of the modification of the layered double hydroxides (LDH) was to change the hydrophilic character of the interlayer to hydrophobic with the purpose of improving its ability to adsorb several (anionic and cationic) dyes from water. These compounds have been used as adsorbents of amaranth (Am), diamine green B (DGB) and brilliant green (BG) dyes. Adsorption tests were conducted using variable pH values, contact times and initial dye concentrations (adsorption isotherms) to identify the optimum conditions for the intended purpose. Adsorbents and adsorption products were characterized by several physicochemical techniques. The results of the adsorption tests showed that the organo-LDH nanohybrids could be efficient adsorbents in the removal of studied dyes from water. Thus, it can be concluded that nanohybrids studied in this work might act as suitable supports in the design of adsorbents for the removal of a wide spectrum of dyes with the aim of reducing the adverse effects on water resources.

Enhanced solar light-mediated photocatalytic degradation of brilliant green dye in aqueous phase using BiPO 4 nanospindles and MoS 2 /BiPO 4 nanorods

Abstract: Herein, we report the enhanced solar light-mediated photocatalytic degradation of brilliant green dye using BiPO4 nanospindles and MoS2/BiPO4 nanorods synthesized by facile hydrothermal process. The synthesized nanomaterials were examined by various techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) attached with energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, and pore size distribution analysis. The detailed characterizations revealed that after the introduction of MoS2, the crystalline phase transformation from hexagonal to monoclinic was observed for BiPO4. The TEM images clearly confirmed that BiPO4 possessed nanospindles and MoS2/BiPO4 exhibited nanorod-shaped morphologies. The photocatalytic activity of synthesized MoS2/BiPO4 nanorod heterojunction was explored for the degradation of brilliant green (BG) dye under solar light irradiation. Interestingly, approximate 80% degradation of BG was observed under solar light in 70 min using MoS2/BiPO4 nanorods as photocatalyst. As an efficient photocatalyst, the synthesized MoS2/BiPO4 nanorod heterojunction exhibited enhanced photocatalytic efficiency as compared to pure BiPO4 nanospindles, commercially available TiO2PC-50 and TiO2 PC-500 under solar light. The high photocatalytic activity of MoS2/BiPO4 nanorod heterojunction could be related to the amended visible light-harvesting tendency, effective charge separation, and facile transportation of photogenerated e−/h+ pairs at the heterojunction interface.

Evaluation of the adsorption kinetics of brilliant green dye onto a montmorillonite/alginate composite beads by the shrinking core model

Abstract: Montmorillonite/alginate composite beads have been studied for adsorption of brilliant green dye in batch experiments. The geometry and features of this clay/polymer composite, in combination with the strong color of the dye, were very useful to apply and test in a simple way the shrinking core model (SCM). This model is very popular for describing adsorption in porous systems, but not in clay/polymer composite beads. The SCM describes the adsorption as a diffusion process of the adsorbate through a spherical shell. The great advantage of using the clay and the dye is that they allow observing with the naked eye or through digital photographs the progress of the front of adsorption (penetration radius) as the reaction takes place. This was never informed in the literature. The experimental changes in penetration radius and dye concentration with time were compared with SCM predictions at different initial concentrations of brilliant green. There was an excellent agreement between theory and experiments, and thus the kinetics of the process could be thoroughly evaluated. The estimated values of the parameters liquid phase mass transfer coefficient and effective diffusion coefficient in the adsorbent are kf > 0.00008 m s−1 and Dp = 5 × 10−10 m2 s−1 respectively.

Novel Technology for the Removal of Brilliant Green from Water: Influence of Post-Oxidation, Environmental Conditions, and Capping.

Abstract: Chemical dyes are used in a wide range of anthropogenic activities and are generally not biodegradable. Hence, sustainable recycling processes are needed to avoid their accumulation in the environment. A one-step synthesis of Fecore-maghemiteshell (Fe-MM) for facile, instantaneous, cost-effective, sustainable, and efficient removal of brilliant green (BG) dye from water has been reported here. The homogenous and monolayer type of adsorption is, to our knowledge, the most efficient, with a maximum uptake capacity of 1000 mg·g-1, for BG on Fe-MM. This adsorbent was shown to be efficient in occurring in time-scales of seconds and to be readily recyclable (ca. 91%). As iron/iron oxide possesses magnetic behavior, a strong magnet could be used to separate Fe-MM coated with BG. Thus, the recycling process required a minimum amount of energy. Capping Fe-MM by hydrophilic clay minerals further enhanced the BG uptake capacity, by reducing unwanted aggregation. Interestingly, capping the adsorbent by hydrophobic plastic (low-density polyethylene) had a completely inverse effect on clay minerals. BG removal using this method is found to be quite selective among the five common industrial dyes tested in this study. To shed light on the life cycle analysis of the composite in the environment, the influence of selected physicochemical factors (T, pH, hν, O3, and NO2) was examined, along with four types of water samples (melted snow, rain, river, and tap water). To evaluate the potential limitations of this technique, because of likely competitive reactions with metal ion contaminants in aquatic systems, additional experiments with 13 metal ions were performed. To decipher the adsorption mechanism, we deployed four reducing agents (NaBH4, hydrazine, LiAlH4, and polyphenols in green tea) and NaBH4, exclusively, favored the generation of an efficient adsorbent via aerial oxidation. The drift of electron density from electron-rich Fecore to maghemite shells was attributed to be responsible for the electrostatic adsorption of N+ in BG toward Fe-MM. This technology is deemed to be environmentally sustainable in environmental remediation, namely, in waste management protocol.