Influence of the Structure and Experimental Surfaces Modifications of 2:1 Clay Minerals on the Adsorption Properties of Methylene Blue

In this work the adsorption capacities of methylene blue on Mg-smectite and sepiolite and its derived material obtained after acid treatment and/or the addition of Fe at its surfaces are studied. Natural smectite with high Mg-content in its octahedral sheet (Mg-smectite) displays higher adsorption capacity than the sepiolite due to the ability of Mg-smectite to expand the basal spacing to accommodate methylene blue cations between adjacent layers and the inability of sepiolite to adsorb these cations within the structural channels. The acid-activation of Mg-smectite causes a clear decrease in the adsorption capacity attributed to the partial loss of the interlayer positions by the loss of the octahedral sheet and subsequent formation of amorphous silica. Moreover, the adsorption of the Mg-smectite decreases even more when iron oxohydroxides species are incorporated in its interlayer spacing making inaccessible the interlayer active sites for the adsorption of methylene blue cations. On the contrary, the microwave-assisted acid treatment of sepiolite causes a slight increase in the adsorption capacity related with the dispersion of fibers. Nevertheless, contrary to that observed with Mg-smectite, higher increasing of adsorption capacities are obtained after the formation of new adsorption centers due to the incorporation of iron oxohydroxides species at the external surfaces of sepiolite.

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Comparative Study on the Adsorption Capacities of the Three Black Phosphorus-Based Materials for Methylene Blue in Water

Sustainability ◽

10.3390/su12208335 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8335

Author(s):

Juanhong Wang ◽

Zhaocheng Zhang ◽

Dongyang He ◽

Hao Yang ◽

Dexin Jin ◽

...

Keyword(s):

Methylene Blue ◽

Adsorption Capacity ◽

Black Phosphorus ◽

Adsorption Effect ◽

Adsorption Sites ◽

Surface Areas ◽

Adsorption Behaviors ◽

Adsorption Capacities ◽

Reduced Graphene ◽

Black Phosphorene

Dye effluent has attracted considerable attention from worldwide researchers due to its harm and toxicity in recent years; as a result, the treatment for dye has become one of the focuses in the environmental field. Adsorption has been widely applied in water treatment owing to its various advantages. However, the adsorption behaviors of the new materials, such as the 2D black phosphorus (BP), for pollution were urgently revealed and improved. In this work, BP, black phosphorene (BPR), and sulfonated BPR (BPRS) were prepared by the vapor phase deposition method, liquid-phase exfoliating method, and modification with sulfonation, respectively. The three BP-based materials were characterized and used as adsorbents for the removal of methylene blue (MB) in water. The results showed that the specific surface areas (SSAs) of BP, BPR, and BPRS were only 6.78, 6.92, and 7.72 m2·g−1, respectively. However, the maximum adsorption capacities of BP, BPR, and BPRS for MB could reach up to 84.03, 91.74, and 140.85 mg·g−1, which were higher than other reported materials with large SSAs such as graphene (GP), nanosheet/magnetite, and reduced graphene oxide (rGO). In the process of BP adsorbing MB, wrinkles were generated, and the wrinkles would further induce adsorption. BPR had fewer layers (3–5), more wrinkles, and stronger adsorption capacity (91.74 mg·g−1). The interactions between the BP-based materials and MB might cause the BP-based materials to deform, i.e., to form wrinkles, thereby creating new adsorption sites between layers, and then further inducing adsorption. Although the wrinkles had a certain promotion effect, the adsorption capacity was limited, so the sulfonic acid functional group was introduced to modify BPR to increase its adsorption sites and promote the adsorption effect. These findings could provide a new viewpoint and insight on the adsorption behavior and potential application of the BP-based materials.

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Effectiveness of Alkali-Acid Treatment in Enhancement the Adsorption Capacity for Rice Straw: The Removal of Methylene Blue Dye

ISRN Physical Chemistry ◽

10.1155/2013/208087 ◽

2013 ◽

Vol 2013 ◽

pp. 1-15 ◽

Cited By ~ 19

Author(s):

Nady A. Fathy ◽

Ola I. El-Shafey ◽

Laila B. Khalil

Keyword(s):

Methylene Blue ◽

Adsorption Capacity ◽

Rice Straw ◽

Acid Treatment ◽

Low Cost ◽

Second Order ◽

Isotherm Models ◽

Blue Dye ◽

Acid Modification ◽

Pseudo Second Order

The effectiveness of alkali-acid modification in enhancement the adsorption capacity of rice straw (RS) for removing a basic dye was studied. The obtained adsorbents were characterized by slurry pH, pHPZC, iodine number, methylene blue number, FTIR, and SEM analyses. Adsorption of methylene blue (MB) was described by the Langmuir, Freundlich, Tempkin, and Redlich-Peterson isotherm models. Effects of contact time, initial concentration of MB dye, pH of solution, adsorbent dose, salt concentration of NaCl, and desorbing agents on the removal of MB were reported. Kinetic studies were analyzed using the pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models and were found to follow closely the pseudo-second-order model. Equilibrium data were best represented by the Langmuir and Redlich-Peterson isotherms. The adsorption capacities were varied between 32.6 and 131.5 mg/g for untreated and treated RS samples with NaOH-1M citric acid (ARS-1C), respectively. Adsorption behavior of the ARS-1C sample was experimented in a binary mixture containing methylene blue (basic) and reactive blue 19 (acidic) dyes which showed its ability to remove MB higher than RB19. Overall, the results indicate that the alkali-acid treatment proved to be potential modification for producing effective low-cost adsorbents for the removal of the basic dyes from wastewater.

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The effect of acid activation and calcination of halloysite on the efficiency and selectivity of Pb(II), Cd(II), Zn(II) and As(V) uptake

Clay Minerals ◽

10.1180/claymin.2016.051.3.06 ◽

2016 ◽

Vol 51 (3) ◽

pp. 385-394 ◽

Cited By ~ 15

Author(s):

Paulina Maziarz ◽

Jakub Matusik

Keyword(s):

Photoelectron Spectroscopy ◽

Active Sites ◽

Structural Changes ◽

Selective Adsorption ◽

Temperature Treatment ◽

High Temperature Treatment ◽

Acid Activation ◽

Subsequent Formation ◽

X Ray ◽

Mineral Structure

AbstractThe present study investigated the efficiency and mechanisms of aqueous Pb(II), Cd(II), Zn(II) and As(V) adsorption on natural (H), calcined (HC), and acid-activated halloysite (HA). The XRD and FTIR measurements indicated that the aluminosilicate framework was not affected by high-temperature treatment, in contrast to acid activation, which led to structural changes mainly in the tetrahedral sheet. The sorption of cations on H sample was low, though it was most effective for As(V). The X-ray photoelectron spectroscopy results suggested that removal of As(V) might be related to its reduction to As(III) involving oxidation of Fe(II) present in the mineral structure and/or iron minerals. The calcination enhanced halloysite sorption capacity for cations, while the As(V) sorption decreased. This was due to partial dehydroxylation and the subsequent formation of additional active sites. The acid treatment induced selective adsorption of Pb(II).

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Textural and structural modifications of saponite from Cerro del Aguila by acid treatment

Clay Minerals ◽

10.1180/0009855013640003 ◽

2001 ◽

Vol 36 (4) ◽

pp. 483-488 ◽

Cited By ~ 14

Author(s):

M. Suárez Barrios ◽

C. de Santiago Buey ◽

E. García Romero ◽

J. M. Martín Pozas

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Acid Treatment ◽

Active Sites ◽

Internal Surface ◽

Acid Activation ◽

Acid Attack ◽

Surface Areas ◽

Treated Sample

AbstractThe physicochemical properties of clays can be modified by acid treatment with inorganic acids. This treatment is usually referred to as ‘acid activation’, because it increases the specific surface area and the number of active sites of the solids. In the present study, the acid activation of saponite from Cerro del Aguila (Madrid, Spain) with HCl solutions was measured. Illite, quartz and small amounts of feldspar were found as impurities in the raw saponite.Acid treatments were carried out with different concentrations of HCl solutions. The samples obtained were characterized by mineralogical and chemical analyses, XRD, FT-IR spectroscopy, N2 adsorption-desorption isotherms and TEM. The acid attack, under the conditions employed, produced a progressive destruction of the structure of saponite by partial dissolution of the octahedral Mg(II) cations. Amorphous silica coming from the tetrahedral sheet of saponite was generated. The specific surface area of the most intensely treated sample (2.5% for 24 h) was doubled with respect to that of natural saponite. This increase in the surface area is due to the increase in both the external and internal surface areas.

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Adsorption Mechanism of Rectorite Modified by Lithium

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.919-921.2017 ◽

2014 ◽

Vol 919-921 ◽

pp. 2017-2021

Author(s):

Yin An Ming ◽

Ying Ru Wang ◽

Zheng Liu ◽

Fu Rong Zhou

Keyword(s):

Methylene Blue ◽

Adsorption Capacity ◽

Adsorption Mechanism ◽

Interlayer Spacing ◽

Blue Dye ◽

Adsorption Efficiency ◽

X Ray Diffraction ◽

X Ray ◽

Index Measurement ◽

Infrared Spectrophotometer

In this paper, the mechanism that lithium-modified rectorite (Rec-Li) and raw rectorite adsorbed methylene blue dye in wastewater was investigated, and the adsorption properties of the two adsorbents were also compared. The results showed that the static saturated adsorption capacity of raw rectorite was 77.75mg/g, however, the capacity of lithium-modified rectorite was up to 189.62mg/g, the adsorption efficiency was increased by 144%. Therefore, the adsorption capacity of Rec-Li to methylene blue was much higher than raw rectorite. The Rec-Li and raw rectorite were characterized respectively by means of fourier transform infrared spectrophotometer (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and colloid index measurement. The analysis indicated that, after modification by lithium, the colloid index was changed from 12mL/3g to 198mL/3g and the interlayer spacing was changed from 0.01~0.1μm to 1~1.5μm. With the increasing of the colloid index, the dispersion effect of adsorbent in wastewater and the contact area between adsorbent and pollutants were improved. And the increase of interlayer spacing was conducive to pollutants entering the hole and so that the adsorption capacity of Rec-Li was increased significantly.

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Char Products From Bamboo Waste Pyrolysis and Acid Activation

Frontiers in Materials ◽

10.3389/fmats.2020.624791 ◽

2021 ◽

Vol 7 ◽

Author(s):

Prakash Parthasarathy ◽

Hamish R. Mackey ◽

Sabah Mariyam ◽

Shifa Zuhara ◽

Tareq Al-Ansari ◽

...

Keyword(s):

Methylene Blue ◽

Activated Carbon ◽

Interior Design ◽

Activated Carbons ◽

Raw Material ◽

Material Surface ◽

Acid Activation ◽

Methylene Blue Adsorption ◽

Surface Areas ◽

Adsorption Capacities

Bamboo is found worldwide but is especially concentrated in tropical and subtropical areas with the major producing nations being China, Indonesia and Thailand with an annual production of 12 million tonnes. It has found uses in many applications such as: furniture, flooring, roofing, fencing, interior design and scaffolding in the construction industry. In this study, discarded waste bamboo furniture was used in the ground form as the raw material feedstock for the production of a series of biochars and activated carbons. The biochars were produced at different temperatures, namely, 723, 823, 923, 1,023, 1,123 and 1223 K, in a muffle furnace inerted with nitrogen and for different pyrolysis times. The product chars yields were 20–30% by weight of the raw material, surface areas were 100–350 m2/g. Other tests include elemental analysis, helium displacement density, pH, ICP-AES on a leachate sample. Four of the different temperature samples of biochar were used to adsorb the basic dye methylene blue and were shown to possess high adsorption capacities. Then, the same bamboo raw material powder was treated with acid and pyrolysed/activated in a nitrogen atmosphere at the same range of temperatures to produce activated carbons; these were characterized using similar test methods to the biochars. The yields are in the range 20–40% by weight of the raw material feedstock and the BET surface areas are in the range 200–600 m2/g. Three of the different temperature activated carbons were used to adsorb methylene blue and the results were compared with the biochar results. All the adsorption experimental isotherm results were analyzed using conventional isotherm equations. The benefits and cost implications of both biochar and activated carbon routes are discussed. The methylene blue adsorption capacities are extremely attractive in the range 0.42–1.12 mmol/g (150–300 mg/g char product) and extend to over 2.35 mmol/g (700 mg/g) for the bamboo derived activated carbons. The micropore and mesopore volumes have been determined under the various char and activated carbon experimental conditions and coupled with the surface areas; these results have been used to explain the trends in the methylene blue adsorption capacities.

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Synthesis of Expanded Graphite: Effect of the graphite flake size on adsorption capacities to Methylene Blue

Vietnam Journal of Catalysis and Adsorption ◽

10.51316/jca.2021.046 ◽

2021 ◽

Vol 10 (3) ◽

pp. xx-xx

Author(s):

Chien Hoang Thi ◽

Ly Vu Thi Huong ◽

Thao Tran Thi ◽

Thuy Vu Thi ◽

Ngan Nguyen Thi ◽

...

Keyword(s):

Methylene Blue ◽

Specific Surface ◽

Adsorption Capacity ◽

Surface Area ◽

Specific Surface Area ◽

Expanded Graphite ◽

Graphite Flake ◽

Adsorption Capacities ◽

First Time

For the first time, the expansion grade of graphite was studied through the effect of the flake size. The result shown the larger flake size exhibits a higher expansion grade. In addition, the more expanded material, the higher specific surface area can be obtained. The synthesized expanded graphites were used for the adsorption of methylene blue. The expanded graphite with the highest expansion grade displayed the highest adsorption capacity due to its specific surface area.

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Effects of EDTA on adsorption of Cd(II) and Pb(II) by low-permeability soil minerals and on their microscopic characteristics

10.21203/rs.2.19991/v1 ◽

2020 ◽

Author(s):

Xueji You ◽

Shuguang Liu ◽

Chaomeng Dai ◽

Guihui Zhong ◽

Yanping Duan ◽

...

Keyword(s):

Adsorption Capacity ◽

Active Sites ◽

Ethylenediaminetetraacetic Acid ◽

Freundlich Isotherm ◽

Batch Adsorption ◽

Low Permeability ◽

Soil Minerals ◽

Adsorption Capacities ◽

Quartz Sands ◽

Site Competition

Abstract Background Ethylenediaminetetraacetic acid (EDTA) can serve as a washing agent in the remediation of low-permeability layers contaminated by heavy metals (HMs). Therefore, batch adsorption experiments, where quartz sands (SM1) and mineral mixtures (SM2) were used as low-permeability soil minerals (SMs), were implemented to explore the effects of different EDTA concentrations, pH and exogenous chemicals on the HM-SM-EDTA adsorption system. Changes in microscopic characterizes of SMs were determined by instrument analysis to investigate the mechanisms.Results As the EDTA concentration increased gradually, it gradually cut down the maximum Cd adsorption capacities of SM1 and SM2 from approximately 135 to 55 mg/kg and 2,660 to 1,453 mg/kg; and the maximum Pb adsorption capacities of SM1 and SM2 were reduced from 660 to 306 mg/kg and 19,677 to 19,262 mg/kg, respectively. When the mole ratio (MR = moles of HM ions / sum of moles of HM ions and EDTA) was closer to 0.5, the effect of EDTA was more effective; and Freundlich isotherm model fitted better to the data. It took 5 to 10 min for EDTA to begin taking its effect. EDTA worked well at pH below 7.0 and 4.0 for Cd and Pb, respectively. Low-molecular-weight organic acids (LMWOAs) affected the system mainly by bridging, complexation, adsorption site competition and reductive dissolution. Cu 2+ , Fe 2+ ions could greatly increase the Cd and Pb adsorption on SM2. There were feature changes in mineral particles including attachment of EDTA and microparticles, agglomeration, connection and smoother surfaces, making the specific surface area decrease from 16.73 to 12.59 m 2 /g.Conclusion All findings indicated that EDTA could effectively and economically reduce the HM adsorption capacity of SMs at the reasonable MR value, contact time and pH. The extent of the effects of LMWOAs and exogenous metal ions on the HM-SM-EDTA system depended on the synthesis of diverse effects and the selectivity of EDTA, respectively. EDTA reduced the HM adsorption capacity of SMs not only by complexation with HM ions, but also decreasing SSA and blocking active sites. Hence, the acquired insight from the presented study can help to promote the remediation of contaminated soil and groundwater.

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Membrane adsorber with hierarchically porous HKUST-1 immobilized in membrane pores by flowing synthesis

10.22541/au.164014626.61650361/v1 ◽

2021 ◽

Author(s):

Ke Bai ◽

Senqing Fan ◽

Yu Chen ◽

Yilin Wang ◽

Jiaojiao Chen ◽

...

Keyword(s):

Mass Transfer ◽

Methylene Blue ◽

Adsorption Capacity ◽

Congo Red ◽

Active Sites ◽

Confined Space ◽

Hierarchically Porous ◽

Membrane Pores ◽

Membrane Adsorber ◽

Adsorption Desorption

A membrane adsorber with hierarchically porous HKUST-1 (HP-HKUST-1) immobilized in membrane pores has been fabricated by flowing synthesis. The XRD characteristics indicated that the structure integrity of the HP-HKUST-1 immobilized in the membrane pores can be kept after template agent removed. Other characteristics presented by XPS, FTIR, SEM, TEM and BET proved the effective immobilization of HP-HKUST-1 in membrane pores. Compared with hydrothermal HKUST-1 powder, the adsorption capacity for Congo red and Methylene blue adsorption can be increased several times by hydrothermal HP-HKUST-1 powder, owing to the mesopores with rich active sites for adsorption. When the solution was flowed through the membrane adsorber, the adsorption rate for these adsorbates increased significantly, owing to the enhanced mass transfer in the confined space of the membrane pores with micro or nano scale. After going through seven adsorption-desorption experiments, the membrane adsorber with HP-HKUST-1 immobilized in membrane pores shows a remarkable repeatability.

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Activated Carbon from Prickly Pear Seed Cake: Optimization of Preparation Conditions Using Experimental Design and Its Application in Dye Removal

International Journal of Chemical Engineering ◽

10.1155/2019/8621951 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 7

Author(s):

Y. El Maguana ◽

N. Elhadiri ◽

M. Bouchdoug ◽

M. Benchanaa ◽

A. Jaouad

Keyword(s):

Methylene Blue ◽

Activated Carbon ◽

Experimental Design ◽

Adsorption Capacity ◽

Carbonization Temperature ◽

Prickly Pear ◽

Acid Activation ◽

Seed Cake ◽

Impregnation Ratio ◽

Preparation Conditions

In the present study, the experimental design method was used to optimize the preparation conditions of an activated carbon from prickly pear seed cake by phosphoric acid activation. The parameters studied include impregnation ratio, carbonization temperature, and carbonization time. The optimal conditions for the preparation of the activated carbon with high adsorption capacity for methylene blue were identified to be an impregnation ratio of 2.9, carbonization temperature of 541°C, and carbonization time of 88 min. The obtained activated carbon was characterized by SEM/EDX, FTIR, pHpzc, and its capacity to adsorb methylene blue. FTIR analysis and pHPZC showed the acidic character of the activated carbon surface. The adsorption capacity of the optimal activated carbon was found to be 260 mg·g−1 for methylene blue. The adsorption equilibrium of methylene blue was well explained by the pseudo-second-order model and Freundlich isotherm. Furthermore, the performance of the produced activated carbon was examined by the methyl orange removal.

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