Papers by Keyword: Methylene Blue (MB)

Abstract: The utilization of Sewage Sludge Ash Pellets (SSAP) as an efficient sorbent material for dye removal is highlighted in this work. On MB removal, the effects of several factors such as contact time, agitation speed, solution pH, adsorbent dosage, and beginning concentration were investigated. When the MB concentration was 25 mg/L, the SSAP concentration was 30 g/L, and the speed was 250 rpm, the maximum removal efficiency was 98 %. The equilibrium time was found to be 60 minutes, and the maximum dye removal occurred at pH 10 for SSAP adsorbents. The Langmuir and Freundlich isotherm models were used to analyze the adsorption data. Adsorption isotherm studies revealed that the Langmuir model fits this case better. In most cases, the R² correlation coefficient value exceeds 0.95. According to the findings of this study, SSAP can be used as an effective adsorbent for the removal of MB from aqueous solutions.

Abstract: Titanium dioxide (TiO₂) nanoparticles have been successfully prepared by biological method and the resulting material was characterized by XRD, FTIR, SEM, EDAX and UV-Vis spectroscopy. The synthesized TiO₂ materials successfully degraded the methylene blue dye (MB) under UV light irradiation.

Abstract: This work presented the high activity of metal-free g-C₃N₄ photocatalyst for methylene blue (MB) removing over natural sunlight irradiation. These g-C₃N₄ photocatalysts materials were synthesized by a conventional thermal condensation method using melamine as a precursor under treated at the various annealing temperatures (450 °C, 500 °C, 550 °C, 600 °C and 650 °C). All as-synthesized samples were characterized and confirmed by a several techniques, such as, X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectrometer (DRS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) specific surface area. XRD and FTIR results confirmed that the as-synthesized g-C₃N₄ samples were completely synthesized at annealing temperature of 500 °C. SEM images showed the morphologies of the g-C₃N₄ samples had more flake-like structures upon the increasing of annealing temperatures. While DRS results indicated that the absorption edges of as-synthesized g-C₃N₄ samples were shifted to visible-light region, except the sample as-synthesized at 650 °C (g-C₃N₄-650 °C). Moreover, the photocatalytic properties of metal-free g-C₃N₄ photocatalyst materials were evaluated by degrading of MB dye solution under natural sunlight irradiation for 100 min. The results revealed that the highest photocatalytic activity was exhibited by the sample synthesized at 600 °C, which the apparent rate constant (k_app.) was 0.0291 min^-1. The orders of activities as: g-C₃N₄-600 °C > g-C₃N₄-650 °C > g-C₃N₄-550 °C > g-C₃N₄-500 °C > g-C₃N₄-450 °C. Hence, the metal-free g-C₃N₄ photocatalyst appears to be an attractive-material for water or wastewater purification applications over activated by sunlight irradiation.

Abstract: This research aims to investigate photocatalytic activities of titanium dioxide (TiO₂) incorporated with reduced graphene oxide (rGO) nanocomposite catalysts. These TiO₂-rGO photocatalysts were easily prepared through a direct-mixing of TiO₂ powder suspended in acidic solution under the different amounts of rGO loading (0.25, 0.50, 0.75 and 1.00 wt%). Then, the obtained TiO₂-rGO samples were characterized by a several techniques. The results demonstrated that the crystalline phases of all samples are corresponding to pristine TiO₂, whereas the characteristic peaks of rGO in the TiO₂-rGO nanocomposites could be observed and also well-confirmed by Raman spectroscopy. TEM results showed that the TiO₂ nanoparticles were well-combined with rGO nanosheets. Moreover, the photocatalytic activities of all TiO₂-rGO photocatalyst samples were evaluated by photodegrading of methylene blue (MB) dye solution under natural sunlight irradiation. The results revealed that all TiO₂-rGO nanocatalysts exhibited much higher activity than those of the bare TiO₂. The improved photocatalytic activity can be attributed to the presence of rGO nanosheets, leading to the decrease of electron (e^-) - hole (h⁺) recombination of TiO₂ catalyst, increasing charge transfer rate of electrons and surface-adsorbed amount of MB molecules which enhances the photocatalytic activity.

Abstract: Copper oxide doped titania nanocatalysts preparation was carried out by combustion synthesis method. The precursor compounds for the preparation of these nanocatalysts were titanium iso propoxide, glycine, copper nitrate and strontium nitrate. The prepared catalysts were characterized by Energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), Scanning electron microscopy (SEM), BET Surface area measurement and Infrared spectroscopy (FTIR). Total acidity of the prepared catalysts were determined by temperature programmed desorption of ammonia (TPD-NH₃). There was no characteristic peak of copper oxide in the XRD pattern. The photo activity of these prepared catalysts was examined for the degradation of methylene blue dye, which is a common environmental pollutant. These catalysts can be used to degrade the dye from water and thus helps the aquatic life.

Abstract: A nanocomposite is a new generation of nanomaterials to improve the tailorable properties of the photocatalytic activity towards the removal of organic and inorganic toxic dyes from the aqueous medium. The hydrothermal technique were used to synthesis the nanocomposite and the particles were examined under the characterization techniques like XRD, UV-Vis, FTIR, FESEM and TEM. The organic and inorganic pollutants can be removed by many of the methods and the best among this is photocatalysis activity. The Methylene Blue (MB), Methylene Violet (MV), Methylene Orange (MO) and Bromophenol Blue (BB) are the two of the dyes which were used in this work. These dyes have excellent photocatalytic Properties to degrade the dyes under the visible light.

Abstract: CeMOF-graphene oxide (GO) composite (CeMOF-nGO, n=1, 5, 9, corresponding to the percentage of GO at 1, 5 and 9%) was synthesized through a facile synthesis method at room temperature. The parent and composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and N₂ adsorption-desorption isotherms. Their photocatalytic degradation of methylene blue in aqueous solution were systematically tested by Ultraviolet-Visible spectrophotometer (UV-Vis). The novel CeMOF-nGO materials exhibit an obvious photocatalytic degradation property and the CeMOF-5GO shows a remarkable catalytic ability in the degradation of methylene blue (86.62%) under visible light. In general, the combination of CeMOF and graphene oxide provides us a bright future to explore the unique properties of rare-earth MOFs-GO composites on degradation of organic pollution and many other fields.

Abstract: Both bentonite and CaCO₃ are cheap and abundant superior regional non-metal ores in Guangxi province, so it is very meaningful to jointly exploit bentonite and CaCO₃ for real applications. In this study, bentonite modified with CaCO₃ (CCB) was prepared and its adsorption performance of Congo Red (CR) and Methylene Blue (MB) was evaluated by investigating the adsorption influencing effects of initial pH, SDBS and phosphate. Adsorption isotherms and adsorption kinetics models were also fitted to analysis the corresponding kinetic characteristics of CCB. The results show that CCB exhibited superior adsorption performance with the respective > 90% MB and CR removal within the initial pH range 2 ~ 10. To a certain extent, MB removal efficiencies by CCB can be increased with the addition of SDBS. On the other hand, CR adsorption on CCB was inhibited slightly in presence of SDBS. But as a whole, removal efficiencies of MB and CR by CCB were kept constant when SDBS co-existed. MB and CR adsorption on CCB decreased to some extent because of competitive adsorption effect when phosphate co-existed. It also demonstrated that CCB can remove phosphate at the same time with dyes. Adsorption models including adsorption isotherms adsorption kinetics indicated that MB and CR adsorption on CCB was a monolayer process, and the adsorption rate depended on both adsorbent and adsorbate. In summary, CCB is a promising adsorbent for dyes removal with many advantages such as simple preparation technology, excellent adsorption performance for anionic and cationic dyes, broad fitting pH range and SDBS resistance. Besides, it can remove dyes together with phosphate at the same time. Therefore, this study is very useful for the dyeing wastewater treatment and exploiting the resources of bentonite and CaCO₃.

Abstract: Magnetic nanocomposite photocatalyst is an alternative approach for easy separation of catalyst from the treated water by magnetic force. This paper will discuss the performance of dye degradation using two different supported layer; Silica and Activated Carbon that shield between magnetic iron oxide (Fe₂O₃) and Titanium dioxide (TiO₂) photocatalyst. Photocatalytic activity is measure using Methylene Blue (MB) as indicator. The magnetic nanocomposite was synthesis using an evaporation indused self-assembly (EISA) approach and wet synthesis method. The photocatalyst were then characterized using Vibrating Sample Magnetometer (VSM), Brunauer-Emmet-Teller (BET), and Transmission Electron Microscope (TEM) and the effect of dye degradation were characterizing using Ultraviolet-Visible (UV-VIS) spectroscopy. The result showed that activated carbon is the good supporter compare to silica.

Abstract: This study investigated the effect of ultraviolet (UV) enhancement and the Fe³⁺-EDTA Complex on the degradation of methylene blue (MB) in Fenton-like system. By studying different variables including H₂O₂ concentration, Fe³⁺-EDTA concentration and pH value，and using MB as a model pollutant, the best experimental conditions was to investigated. Experimental results showed that it is possible to degrade MB wastewater effectively by modified UV-Fenton with Fe³⁺-EDTA at neutral pH. Besides, optimality condition (pH= 7, [Fe³⁺-EDTA] = 2 mmol/L, [H₂O₂] = 10 mmol/L) which were used in the modified UV-Fenton that achieves a removal of over 95% of the MB in 60 min reaction time. Therefore, this new modified Fenton system is an effective treatment for MB wastewater.