Brilliant green 0.5% topical solution

The magnetic MgFe2O4 nanoparticles (NPs) were fabricated via a facile co-precipitation technique and was comprehensively characterized by XRD, FTIR, SEM, EDX and VSM. The prepared NPs were used as catalyst in presence of ultrasound (US) irradiation to activate persulfate (PS) for generation of sulfate radicals (SO4·-) for boosted degradation of toxic Brilliant Green (BG) dye. Preliminary experiments revealed that highest BG dye degradation efficiency of 91.63% was achieved at MgFe2O4 catalyst dose of 1.0 g/L, PS dose of 300 mg/L, and initial dye concentration of 70 ppm within 15 min of US irradiation. However, only US, US in presence of PS oxidation and US in presence of MgFe2O4 catalyst have shown 20.2%, 83.6% and 45.0% of BG dye removal, respectively. Furthermore, response surface methodology (RSM) based central composite design (CCD) was executed to investigate the effect of interaction between independent variables such as MgFe2O4 catalyst dose (0.5–1.5 g/L), PS dose (150–350 mg/L), initial BG dye concentration (50–150 ppm) and US irradiation time (4–12 min). The RSM based quadratic model was used to predict the experimental data, and the prediction accuracy was confirmed by analysis of variance (R2 = 0.98). The established RSM model has predicted the optimum experimental conditions as MgFe2O4 catalyst dose of 0.75 g/L, PS dose of 300 mg/L, initial dye concentration of 75 ppm and sonication time of 10 min. Subsequently, the treatment cost analysis was performed for all thirty experimental runs of CCD, and the RSM predicted response was found to be evidently optimum as this has delivered best economic condition (140 $/kg of BG removed) with respect to relative dye removal (%). COD removal and residual sulfate analysis have demonstrated satisfactory reduction of COD (90.31%) as well as sulfate ions (42.87 ppm) in the dye solution after treatment. Results of degradation pathway analysis portrayed the transformation of BG molecule (M/Z ratio 385) into simpler fractions with M/Z ratio of 193, 161, 73, and 61. Moreover, the toxicity analysis revealed that sono-catalytically activated PS system has efficiently reduced the toxicity level of BG dye from 93.9% to 5.13%.

Abstract licence: CC BY-NC-ND

In this study, seeking to get a more efficient adsorbent, comparable to the commercially available adsorbent, is attracting significant interest as a good adsorbent for wastewater treatment. An approach according to the use of ZnO NPs loaded on the surface of carbon nanotube (ZnO/CNT) nanocomposite to adsorb Brilliant green (BG) dye. ZnO/CNT nanocomposite was chemically synthesized by hydrothermal method and the physicochemical properties were analyzed extensively by using several techniques such as as Fourier-Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray spectroscopy, (EDX), Transmission electron microscopy (TEM), and Thermogravimetric analysis TGA. The effect of different parameters on adsorption processes such as equilibrium time, pH of solution, adsorbent dosage as well as initial concentration of dye has been examined. Results show contact time was (2.00 h), based on the outputs, high capacity of adsorption even at higher initial concentration of dye. With regard to the kinetic analysis, a pseudo second order kinetic model could successfully describe the process of adsorption (R2 0.9910). Then, we used Langmuir, Freundlich isotherm models to obtain the best fit, indicating the role of a multilayer formation for adsorption of BG on the ZnO/CNT nanocomposite from an aqueous solution. Also, the best multilayer adsorption capacity of BG reached to 94.29 mg g−1. The change in free energy of Gibbs (ΔG), entropy (ΔS), and enthalpy (ΔH) were calculated from experimental adsorption results. The obtained negative value of (ΔG) and positive value of (ΔH) show spontaneous nature and endothermic nature of the adsorption process. The regenerated adsorbents in the acidic media (pH 4.0) and basic media (pH10.0) for their performance to removal of BG. The best regenerating has been distilled water. Therefore, it suggests that (ZnO/CNT nanocomposite) is an effective adsorbent and friendly environmentally and inexpensive substance for effective elimination of the dye from wastewater effluent.

Abstract licence: CC BY-NC-ND

Areca nut husk, an inexpensive, easily available agricultural by-product modified with sodium hydroxide has been applied to remove Brilliant green (BG) dye from aqueous solution. Surface characteristics and the elemental composition of areca nut husks were examined using Scanning electron microscope (SEM) and Energy dispersive X-ray (EDX). The chemical treatment changes the surface morphology of the areca nut husk. The alkali treatment removes natural wax, resins and lignin from husks and thus it added extra active surface area and pores for better adsorption. The Fourier-transform infrared (FTIR) spectroscopy indicated that the presence of functional groups (-OH), (-C=O), (-C=C), (-COOH). Experiments were performed in batch adsorption procedure. The optimum removal of 97% BG dye was obtained at pH 7.0, adsorbent dosage 10 g/L, initial concentration 100 mg/L, agitation speed 200 rpm and temperature 298 K. Adsorption data fit better to Langmuir model in comparison with Freundlich, Temkin and Dubinin-Radushkevich isotherm model. The maximum adsorption capacity of 18.21 mg/g was obtained. Kinetic date followed pseudo-second-order rate kinetic better than pseudo-first-order model. The thermodynamic parameters ΔH0 = 12.522 kJ/mol and ΔS0 = 0.044 J/mol indicate endothermic and spontaneous adsorption process. Taking considerations of all experimental results and model analysis, it is concluded that sodium hydroxide treated areca nut husk is a good, low cost and effective biosorbent for the removal of BG dye from aqueous solution.

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Ultrasonication method was used in the incorporation of mesoporous silica (mSiO2) on BiVO4 nanoparticles. The average crystallite size of the BiVO4 nanoparticles was controlled at around 2.4–5.1 nm on mesoporous silica surface. The composites were systematically evaluated as photocatalysts for the degradation of methylene blue (MB) and brilliant green (BG) dyes as a function of mesoporous SiO2 content. A marked compositional dependence of the photocatalytic activity was evidenced for MB and BG degradation under visible light. Compared with the corresponding bare bismuth vanadate nano species, the mSiO2-involved nanocomposites display enhanced photocatalytic activities. The enhancement of photocatalytic activity of BiVO4 nanoparticles with mesoporous silica was attributed to the synergistic effect between mesoporous silica and BiVO4 which improved the separation of photogenerated electrons and holes. Structures and morphologies of the samples were examined by TEM, SEM, XRD, EDS, FT-IR and UV–visible spectroscopy. The effects of operational parameters like dye concentration, mSiO2 content, calcination temperature and reaction time have been analyzed. The results showed that the photocatalytic activity of mSiO2/BiVO4 nanocomposites increases with the modification of BiVO4 by changing the content from 1.0 to 15.0 wt % mesoporous SiO2, the sample of 10.0 wt. % mesoporous SiO2 loaded on BiVO4 showed the higher photocatalytic activity. As the silica in the composites has a very good contact with the BiVO4 nanoparticles it enhances the photo-electron conversion of BiVO4 by reducing the recombination of photo-generated electron–hole pairs based on the band structures of BiVO4. The catalyst is found to be reusable.

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In this research, a single-stage batch adsorber was designed for removal of brilliant green dye from aqueous solutions using activated carbon derived from date pits based on the Freundlich isotherm which was the best-fitted isotherm model.

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