scholarly journals The Removal of Methylene Blue Dye from Aqueous Solutions Using Activated and Non-Activated Bentonites

2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.

2020 ◽  
Vol 32 (10) ◽  
pp. 2624-2632
Author(s):  
C.S. Nkutha ◽  
N.D. Shooto ◽  
E.B. Naidoo

This work reports the feasibility of using pristine and chemically modified coral limestones by acid and base. Their potential adsorptive capabilities is probed by treatment of toxic Cr(VI), Pb(II) ions and methylene blue in aqueous solution under different experimental parameters by batch method. Parameters such as agitation time, concentration, temperature and pH were varied to understand the sorption behaviour of the adsorbents in each case. The adsorbents were characterized by SEM, XRD and FTIR. Morphological analysis by SEM micrographs show that the surface of all adsorbents was irregular in nature. XRD spectra confirmed the orthorhombic structure of aragonite in the pristine coral limestones (PCL), acid modified coral limestones (ACL) and base modified coral limestones (BCL). FTIR results affirmed the presence of (CO3 2-) and (-C=O) groups of the carbonate ions and Ca-O attachment to the surface of PCL and removal of CaCO3 characteristic peaks in ACL and BCL. However, in the modified adsorbents shifting of Ca-O peaks occurred. The recorded maximum adsorption capacities of PCL, ACL and BCL for Cr(VI) ions were 69.42, 65.04, 64.88 mg/g, Pb(II) ions 39.36, 74.11, 78.34 mg/g and methylene blue 37.24, 46.28, 46.39 mg/g, respectively. The uptake of Pb(II), Cr(VI) ions, methylene blue onto PCL fitted Freundlich model. Also the uptake of Cr(VI) ions and methylene blue onto ACL and BCL fitted Freundlich isotherm. However, uptake of Pb(II) ions onto both ACL and BCL fitted Langmuir isotherm. The data revealed that the adsorption of Pb(II) ions onto PCL and ACL and methylene blue dye onto PCL was exothermic. Whilst the adsorption of Cr(VI) ions onto PCL, ACL and BCL and methylene blue dye onto ACL and BCL were endothermic in nature, hence increasing the temperature would enhance the uptake of Pb(II) ions onto BCL, Cr(VI) ions onto ACL and BCL and methylene blue onto ACL and BCL. The obtained (ΔGº) values at all studied temperatures for the adsorption of Pb(II), Cr(VI) ions and methylene blue onto PLC, ACL and BCL indicated a spontaneous process.


Author(s):  
Sridharan Balu ◽  
Kasimayan Uma ◽  
Guan-Ting Pan ◽  
Thomas C.-K. Yang ◽  
Sayee Kannan Ramaraj

Semiconductor materials have been shown to have better photocatalytic behavior and can be utilized for the photodegradation of organic pollutants. In this work, three-dimensional flower-like SnS2 were synthesized by a facile hydrothermal method. Core-shell structured SiO2@α-Fe2O3 nanocomposites were then deposited on the top of the SnS2 flowers. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and photoluminescence spectroscopy (PL). The photocatalytic behavior of the SnS2-SiO2@α-Fe2O3 nanocomposites was observed by observing the degradation of methylene blue (MB). The results show an effective enhancement of photocatalytic activity for the degradation of MB especially for the 15 wt. % SiO2@α-Fe2O3 nanocomposites on SnS2 flowers.


2020 ◽  
Vol 32 (12) ◽  
pp. 3203-3208
Author(s):  
J.P. Shubha ◽  
B.S. Prathibha ◽  
N. Jayalakshmi

Green fuel perished curd was used to synthesize ZnO/Ag/NiO ternary heterostructure with zinc nitrate, nickel carbonate and silver nitrate as oxidizers. The obtained nanostructure was characterized by various analytical techniques such as powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (FESEM), transmission electron microscopy (TEM). The particles and flakes composition of ZnO/Ag/NiO nanomaterials was confirmed. Photocatalytic activity of ZnO/Ag/NiO was evaluated with methylene blue dye by source of light, concentration of hydrogen ion, catalyst and dye concentrations. The obtained ZnO/Ag/NiO nanoparticles reveal better catalytic property for the photodegradation of methylene blue dye under visible light.


In the present investigation , neem leaves are obtained from the agricultural fields and its potential for the removal of dye is tested with the model system of methylene blue in water . The MB has health hazards, its been reported that exposures to the dyes cause allergic reactions, and hence its reflected as toxic. The results obtained from batch experiments are quite useful in giving information about the efficacy of dye-adsorbent system. The influence of factors such as the initial pH value, adsorbent dose, and time of contact was investigated. The results indicate that the percentage removal also increased with the rise in the adsorption capacity (qe). 82% of colour elimination can be obtained at the dose of 100g/l NLP for methylene blue of 10mg/l concentration. The optimal parameters for this experiment were 10mg/l for initial dye concentration, 5gm/50ml adsorbent dosage and pH 8. In the batch system, the adsorption capacity was increased when the parameters were increased until it achieved the equilibrium. Langmuir adsorption isotherm graphics plotted with l/qevis 1/Ce. Trend lines for the adsorption data of different concentration of methylene blue with neem leave as adsorbent is plotted. The linear regression was piloted using plot l/qevis 1/Ce; it was found that R2 value are quite closer to 1 signifying Langmuir isotherm as a good fit for this experimental data. Results indicated that neem leaves has potential to remove Methylene Blue Dye from aqueous streams and can be successfully used as a low cost adsorbent.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Mih Venasius Nsom ◽  
Ekane Peter Etape ◽  
Josepha Foba Tendo ◽  
Beckley Victorine Namond ◽  
Paul T. Chongwain ◽  
...  

Pectin-starch magnetite hybrid nanoparticles were fabricated, characterized, and evaluated as potential absorbents for methylene blue dye based on recycling water from the textile industry. The nanocomposite adsorbent was synthesized with the iron salt coprecipitation method, and the precipitates obtained were sponge-like. The effects of a pectin : starch ratio in the absorbent and the amount of methylene blue adsorbed were investigated. The nanocomposites obtained were characterized using a Fourier-transform infrared spectroscopy (FTIR), before and after methylene blue adsorption. Fourier-transform infrared spectroscopy (FTIR) spectra provided the evidence that the starch-pectin iron oxide hybrid nanoparticles were successfully synthesized. It also indicated that the hybrid nanoparticles actually absorbed the methylene blue dye from the effluent. PXRD results showed that the synthesized hybrid composite adopted the spinel microstructure of Fe3O4 though the crystallinity of the composite decreased with an increase in the pectin : starch ratio. Furthermore, calculations based on PXRD showed that the synthesized powders were nanoparticles. The amount of adsorbed dye by hybrid adsorbent increased with an increase in the starch : pectin ratio, and the increase was better observed at a low polymer concentration of 18%. The amount of adsorbed dye by hybrid adsorbent was high at high pH and low at low pH value which attested to the ion exchange and electrostatic force mechanism during the adsorption process. Finally, the capacity of the absorbent decreased with an increase in temperature.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fiza Akram ◽  
Muhammad Saeed ◽  
Javaid Akhtar ◽  
Syed Ali Raza Naqvi ◽  
Atta ul Haq

Abstract This study reports the fabrication of Fe2O3, Bi2O3, and BiFeO3, characterization and evaluation of the photocatalytic performances for methylene blue dye degradation. The materials were synthesized by precipitation method and characterized by scanning electron microscopy, X-ray diffraction, energy dispersive X-rays analyses, and Fourier transform infrared analyses. The photocatalytic activities of Fe2O3, Bi2O3, and BiFeO3 were compared by performing degradation experiments with 50 mL of 100 mg/L methylene blue solution. The as-prepared BiFeO3 was found as 2.4 times and 1.7 times more effective than Fe2O3 and Bi2O3, with a 79, 47, and 57% catalytic activity, respectively. The degradation of methylene blue over the BiFeO3 catalyst was optimized in terms of pH, catalyst dosage, temperature, and methylene blue concentration. The Eley–Rideal mechanism was proposed to describe the reaction kinetics in terms of the first order and second order kinetics model. Activation energy E (kJ/mol), enthalpy ΔH (kJ/mol), entropy ΔS (J/mol) and free energy ΔG (kJ/mol) were calculated as 20.8, 18.2, 197.5 and −45.3 respectively. The negative value of free energy shows that photodegradation is favored in present conditions.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Adugna Nigatu Alene ◽  
Gietu Yirga Abate ◽  
Adere Tarekegne Habte

Background. Dyes are one of the most hazardous materials in industrial effluents which can cause several health problems in living organisms. The removal of dye from colored effluents has attracted increasing attention in the last decade. In this study, raw, beneficiated, and activated waste ash were evaluated as adsorbents for removal of methylene blue (MB) from aqueous solution by the batch adsorption method. Comprehensive characterization studies were carried out on each bioadsorbent, such as proximate analyses, bulk density, specific surface area, point of zero charge, pH, and Fourier transform infrared (FTIR) spectroscopy (which shows functional groups on adsorbents surface). The effects of pH, adsorbent dosage, initial dye concentration, and contact time were determined in order to know the optimum condition and adsorption potential of the adsorbents. The methylene blue (MB) removal efficiency of raw, beneficiated, and activated bioadsorbents from aqueous solutions was found to be 95.212%, 89.172%, and 84.504%, respectively. It is reported that adsorption efficiency of MB on each adsorbent was quite different due to electrostatic and dispersion interaction between the dye molecules and the surface property of the adsorbents. The obtained results were well fitted with the Freundlich isotherm model, and the adsorption process follows the pseudo-second-order kinetics model for all adsorbents. In fact, the results showed that raw, beneficiated, and activated waste ash bioadsorbents could be employed as effective and economical alternative material in the near future.


2011 ◽  
Vol 295-297 ◽  
pp. 1447-1450 ◽  
Author(s):  
Jun Tan Liu ◽  
Huan Gao ◽  
Shi Jing Liu

Using ·OH from Fenton’s reagent, the strong oxidation treatment of methylene blue dye wastewater can destruct the chromophore in organic compounds, and yield CO2, H2O and small molecule inorganic compounds by oxidative degradation finally. The influence of Fenton's reagent dosage, initial pH, and reaction time on the degradation effect was studied. The experimental results show that the decolorization rate of 100mL 20mg/L methylene blue dye wastewater can achieve 96% in the conditions of 0.02g FeSO4·7H2O, 1mL 30% H2O2, initial pH at 3.0 ~4.0, reaction time is 30 min, at room temperature. This treatment of dye wastewater is easy to operate and with good effect.


2014 ◽  
Vol 970 ◽  
pp. 29-32 ◽  
Author(s):  
Pongsaton Amornpitoksuk ◽  
Sumetha Suwanboon

The co-effect of PO43- and I- on the formation of a heterosturucture photocatalyst in the Ag3PO4-AgI system was studied by the co-precipitation method between AgNO3 and the precipitating agent. The precipitating agent was prepared by varying the mole ratios between Na2HPO4 and KI. At 10 mol.% KI, the product showed the mixed phase between Ag3PO4 and un-identified phase. For 30 - 90 mol.% KI, the un-identified phase and AgI were detected in the x-ray diffraction patterns. The un-identified phase strongly adsorbed the methylene blue dye. The product prepared from 30 mol.% KI had the highest content of un-identified phase and also showed the highest degree of decolorization in the dark. The photocatalytic properties of products in this system were confirmed by the decolorization of methylene blue under visible illumination.


Author(s):  
Aline Haas ◽  
Eliane Pereira dos Santos

 With the great generation of colored effluents, several methods for the removal of the color are used, being one of them the method of adsorption in solid medium. In this paper, the in natura orange peel was used as the alternative biomass for the adsorption process of methylene blue, which was characterized by moisture content, pH, apparent density, iodine number, and methylene blue index. To determine the adsorptive capacity of the methylene blue dye, pH 7 was obtained as favorable, the adsorption process showed an adsorption of 82% of the methylene blue dye and a 10 min equilibrium time, where the Freundlich isotherm presented a better adaptation to the adsorption process in orange peel, with its maximum adsorption capacity of 3.9630 mg g-1, for the methylene blue dye. 


Sign in / Sign up

Export Citation Format

Share Document