Enhanced adsorption removal of anionic dyes via a facile preparation of amino-functionalized magnetic silica

A novel amino-functionalized magnetic silica (Fe3O4@SiO2-NH2) was easily prepared via a one-step method integrating the immobilization of 3-aminopropyltriethoxysilane with a sol-gel process of tetraethyl orthosilicate into a single process. This showed significant improvement in the adsorption capacity of anionic dyes. The product (Fe3O4@SiO2-NH2) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, zeta potential and vibrating sample magnetometry. The adsorption performance of Fe3O4@SiO2-NH2 was then tested by removing acid orange 10 (AO10) and reactive black 5 (RB5) from the aqueous solutions under various experimental conditions including initial solution pH, initial dye concentrations, reaction time and temperature. The results indicated that the maximum adsorption capacity of AO10 and RB5 on Fe3O4@SiO2-NH2 was 621.9 and 919.1 mg g−1 at pH 2, respectively. The sorption isotherms fit the Langmuir model nicely. Similarly, the sorption kinetic data were better fitted into the pseudo-second order kinetic model than the pseudo-first order model. In addition, the thermodynamic data demonstrated that the adsorption process was endothermic, spontaneous and physical. Furthermore, Fe3O4@SiO2-NH2 could be easily separated from aqueous solutions by an external magnetic field, and the preparation was reproducible.

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Core-Shell Structured Magnetic Carboxymethyl Cellulose-Based Hydrogel Nanosorbents for Effective Adsorption of Methylene Blue from Aqueous Solution

Polymers ◽

10.3390/polym13183054 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3054

Author(s):

Yiming Zhou ◽

Te Li ◽

Juanli Shen ◽

Yu Meng ◽

Shuhua Tong ◽

...

Keyword(s):

Methylene Blue ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Carboxymethyl Cellulose ◽

Chemical Properties ◽

Polymer Nanocomposite ◽

Core Shell ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Solution Ph

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.

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Adsorption of Pb2+ ions from aqueous solutions by gelatin/activated carbon composite bead form

Adsorption Science & Technology ◽

10.1177/0263617417693006 ◽

2017 ◽

Vol 36 (1-2) ◽

pp. 355-371 ◽

Cited By ~ 6

Author(s):

Fareeda Hayeeye ◽

Qiming J Yu ◽

Memoon Sattar ◽

Watchanida Chinpa ◽

Orawan Sirichote

Keyword(s):

Activated Carbon ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Ph Value ◽

Carbon Composite ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Experimental Conditions ◽

Composite Bead

Gelatin and activated carbon materials have been combined together to obtain a gelatin/activated carbon composite bead form which is ecofriendly, nontoxic, biocompatible, and inexpensive material. In this paper, gelatin/activated carbon adsorption for Pb2+ ions from aqueous solutions was studied experimentally under various conditions. The experimental conditions such as contact time, solution pH, and gelatin/activated carbon dosage were examined and evaluated by using batch adsorption experiments. The maximum adsorption capacity of gelatin/activated carbon for Pb2+ ions was obtained to be 370.37 mg g−1. This maximum capacity was comparable with that of commercial ion exchange resins and it was much higher than those of natural zeolites. The uptake process for Pb2+ ions was found to be relatively fast with 92.15% of the adsorption completed in about 5 min in batch conditions. The adsorption capacity was also strongly solution pH dependent. Adsorption was observed at pH value as low as 2.0 and maximum adsorption was achieved at a pH of approximately 5. The results indicated that the gelatin/activated carbon was effective to be used as an adsorbent for Pb2+ ions removal in wastewater treatment.

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Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers

Applied Sciences ◽

10.3390/app10051738 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1738

Author(s):

Kay Thwe Aung ◽

Seung-Hee Hong ◽

Seong-Jik Park ◽

Chang-Gu Lee

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Equilibrium Studies ◽

Naoh Solution ◽

Surface Modified ◽

Pan Fibers

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.

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Adsorptive removal of phosphate by a Fe–Mn–La tri-metal composite sorbent: Adsorption capacity, influence factors, and mechanism

Adsorption Science & Technology ◽

10.1177/0263617420942709 ◽

2020 ◽

Vol 38 (7-8) ◽

pp. 254-270

Author(s):

Yuanrong Zhu ◽

Xianming Yue ◽

Fazhi Xie

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Phosphate Removal ◽

Maximum Adsorption Capacity ◽

Hydroxyl Groups ◽

Metal Composite ◽

Order Kinetic ◽

Composite Sorbent ◽

Composite Adsorbent

Reducing input of phosphorus is the key step for control of eutrophication and algal blooming in freshwater lakes. Adsorption technology is a cost-effective technology for phosphate removal in water for the purpose. Thus, in this study, a novel Fe–Mn–La tri-metal composite sorbent was developed, and then evaluated for phosphate removal. The results showed that the maximum adsorption capacity could be approached to 61.80 mg g−1 at 25°C under pH of 6.03. Adsorption of phosphate by Fe–Mn–La tri-metal composite adsorbent fitted better by pseudo-second-order kinetic equation and Langmuir model, which suggested that the adsorption process was surface chemical reactions and mainly in a monolayer coverage manner. The thermodynamic study indicated that the adsorption reaction was an endothermic process. The phosphate removal gradually decreased with the increasing of pH from 3.02 to 11.00. The sequence of coexisting anions competing with phosphates was that CO32− > Cl− > SO42− > NO3−. Dissolved organic matter, fulvic acid as a representative, would also decrease adsorption capacities of phosphate by Fe–Mn–La tri-metal composite adsorbents. Adsorption capacity would be decreased with increasing addition of adsorbents, while removal efficiency would be increased in this process. The Fe–Mn–La tri-metal composite adsorbent showed a good reusability when applied to removal of dissolved phosphate from aqueous solutions. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy analyses indicated that some hydroxyl groups (–OH) on the surface of adsorbent were replaced by the adsorbed PO43−, HPO42−, or H2PO4−. Aggregative results showed that the novel Fe–Mn–La tri-mental composite sorbent is a very promising adsorbent for the removal of phosphate from aqueous solutions.

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Sorptive removal of phenanthrene from aqueous solutions using magnetic and non-magnetic rice husk-derived biochars

Royal Society Open Science ◽

10.1098/rsos.172382 ◽

2018 ◽

Vol 5 (5) ◽

pp. 172382 ◽

Cited By ~ 7

Author(s):

Wei Guo ◽

Shujuan Wang ◽

Yunkai Wang ◽

Shaoyong Lu ◽

Yue Gao

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Functional Groups ◽

Rice Husk ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Adsorption Data ◽

Magnetic Modification ◽

Pseudo Second Order ◽

Rice Husk Biochar

A magnetically modified rice husk biochar (MBC) was successfully prepared by a hydrothermal method from original biochar (BC) and subsequently used to remove phenanthrene (PHE) from aqueous solutions. The porosity, specific surface area and hydrophobicity of BC were significantly improved (approx. two times) after magnetic modification. The adsorption data fitted well to pseudo-second-order kinetic and Langmuir models. Compared with BC, MBC had a faster adsorption rate and higher adsorption capacity of PHE. The adsorption equilibrium for PHE on MBC was achieved within 1.0 h. The maximum adsorption capacity of PHE on MBC was 97.6 mg g −1 based on the analysis of the Sips model, which was significantly higher than that of other sources of BCs. The adsorption mechanism of the two BCs was mainly attributed to the action of surface functional groups and π–π-conjugated reactions. The adsorption of PHE on MBC mainly occurred in the functional groups of C–O and Fe 3 O 4 , but that on BC was mainly in the functional groups of –OH, N–H, C=C and C–O.

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Cobalt-Iron Alloy Nanoparticles Impregnated Partially Graphitized Carbon Adsorbent from Metallized Bagasse for Organic Pollutants Removal

10.26434/chemrxiv.13168574.v1 ◽

2020 ◽

Author(s):

Sai Rashmi M. ◽

Akhila S. ◽

Velvita Duas ◽

Ashish Singh ◽

Akshaya Samal ◽

...

Keyword(s):

Adsorption Capacity ◽

Dye Adsorption ◽

Iron Alloy ◽

Carbon Adsorbent ◽

Water Remediation ◽

Maximum Adsorption Capacity ◽

Anionic Dyes ◽

Experimental Conditions ◽

Hair Dye ◽

Methylene Orange

<div><p>Here, we report a highly efficient adsorbent obtained from the carbonization of metallized bagasse. The material is characterized using FESEM, HRTEM, PXRD, zeta-potential and VSM techniques. The material shows an impressive adsorbent property for anionic dyes, pharmaceutical (paracetamol) along with commercially used ‘hair dye’. Further, pH triggered adsorption of Methylene orange (MO), Congo red (CR), Amido black (AB), and paracetamol were studied and results show an impressive adsorption capacity of 1102.9, 1253.9, 877.2, 227.8 mg/g respectively. It is seen that under experimental conditions, adsorbent shows ultrafast adsorption kinetics where ~96% AB dye gets adsorbed in just 5 min, 93% of CR adsorption in 5 min and ~89% of MO adsorption in 5 min. Also, we could observe fast adsorption rate for commercially used ‘hair dye’ and paracetamol drug. Interestingly, in just 5 min, 95% of hair dye adsorption is seen and ~84% drug removal with maximum adsorption capacity of , recyclability of the adsorbent demonstrates the practical benefits of the material for waste water remediation.</p></div>

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Surface Modification of Bentonite with Polymer Brushes and Its Application as an Efficient Adsorbent for the Removal of Hazardous Dye Orange I

Nanomaterials ◽

10.3390/nano10061112 ◽

2020 ◽

Vol 10 (6) ◽

pp. 1112 ◽

Cited By ~ 3

Author(s):

Wenjuan Guo ◽

Ahmad Umar ◽

Yankai Du ◽

Luyan Wang ◽

Meishan Pei

Keyword(s):

Polymer Brushes ◽

Adsorption Property ◽

Gravimetric Analysis ◽

Order Kinetic ◽

X Ray Diffraction ◽

Anionic Dyes ◽

Solution Ph ◽

Experimental Conditions ◽

Pseudo Second Order ◽

First Time

Poly(2-(dimethylamino)ethyl methacrylate)-grafted bentonite, marked as Bent-PDMAEMA, was designed and prepared by a surface-initiated atom transfer radical polymerization method for the first time in this study. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) were applied to characterize the structure of Bent-PDMAEMA, which resulted in the successful synthesis of Bent-PDMAEMA. As a cationic adsorbent, the designed Bent-PDMAEMA was used to remove dye Orange I from wastewater. The adsorption property of Bent-PDMAEMA for Orange I dye was investigated under different experimental conditions, such as solution pH, initial dye concentration, contact time and temperature. Under the optimum conditions, the adsorption amount of Bent-PDMAEMA for Orange I dye could reach 700 mg·g−1, indicating the potential application of Bent-PDMAEMA for anionic dyes in the treatment of wastewater. Moreover, the experimental data fitted well with the Langmuir model. The adsorption process obeyed pseudo-second-order kinetic process mechanism.

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Modified Vermiculite as Adsorbent of Hexavalent Chromium in Aqueous Solution

Minerals ◽

10.3390/min10090749 ◽

2020 ◽

Vol 10 (9) ◽

pp. 749

Author(s):

Celia Marcos ◽

Valeria Medoro ◽

Alaa Adawy

Keyword(s):

Adsorption Capacity ◽

Adsorption Energy ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Ion Chemistry ◽

Solution Ph ◽

Cooperative Process ◽

Order Kinetic Model ◽

Initial Adsorption ◽

Initial Adsorption Rate

The aim of this study was to investigate the efficiency of removing Cr6+ from aqueous solutions using two exfoliated vermiculite: (1) heated abruptly at 1000 °C and (2) irradiated with microwave radiation. The effects investigated were contact time, adsorbate concentration and initial Cr6+ concentration. The adsorption with both exfoliated vermiculites was well described by the DKR isotherm, indicative of a cooperative process and with the pseudo second order kinetic model. The Kd value for the two exfoliated vermiculites was similar, 0.2 ·1010 μg/Kg. The maximum adsorption capacity of Cr6+ with thermo-exfoliated vermiculite, 2.81 mol/g, was much higher than with microwave irradiated vermiculite, 0.001 mol/g; both values were obtained with 0.5 g of vermiculite in contact with distilled water enriched with 1 ppm of Cr6+ for 24 h. Factors such as ion chemistry, the solution pH and ionic strength, influence the values of capacity, adsorption energy and initial adsorption rate values of the exfoliated vermiculite. In addition, these values depended on the exfoliation process, being the adsorption capacity highest with abrupt heating of vermiculite, while the adsorption energy and rate values showed just a slight increase with microwave irradiation. This aspect is important to select the most suitable vermiculite modification treatment to use it as an adsorbent.

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Examination of the Effectiveness of Physical and Chemical Activation of Natural Bentonite for the Removal of Heavy Metal Ions from Aqueous Solutions

Adsorption Science & Technology ◽

10.1260/026361702320360577 ◽

2002 ◽

Vol 20 (2) ◽

pp. 151-167 ◽

Cited By ~ 4

Author(s):

Fawzi Banat ◽

Sameer Al-Asheh ◽

Leena Abu-Aitah

Keyword(s):

Aqueous Solutions ◽

Metal Ions ◽

Adsorption Capacity ◽

Chemical Activation ◽

Sodium Dodecyl ◽

Batch Adsorption ◽

Initial Material ◽

Solution Ph ◽

Experimental Conditions ◽

Activated Bentonite

The ability of physically and chemically activated bentonite to adsorb copper and nickel ions from aqueous solutions was examined under various experimental conditions. Physically activated bentonite was obtained by thermal treatment of the initial material in an oven at 700°C (T-bentonite), while chemically activated bentonite was obtained in two ways, either by treatment of the initial material with sodium dodecyl sulphate (SDS) as an anionic surfactant to give SDS-bentonite or with aluminium hydroxypolycation as a pillaring agent to give Al-bentonite. Batch adsorption tests were undertaken to study the removal of Cu2+ and Ni2+ ions from aqueous solutions using the above-mentioned types of activated bentonite. The adsorption capacity of the bentonites towards both Cu2+ and Ni2+ ions followed the order: Al-bentonite > SDS-bentonite > T-bentonite > natural bentonite. The initial metal concentration, solution pH, temperature and salinity of the solution affected the adsorption capacity towards both metal ions. The uptake of Cu2+ ions increased with an increase in temperature (25–45°C) as well as with an increase in the initial pH of the solution (3–5). The uptake of Cu2+ and Ni2+ ions decreased significantly with an increase in the NaCl and KCl concentrations present in the aqueous solution. Sulphuric acid of 0.1 M concentration was found to be an effective desorbent for bentonite laden with heavy metals.

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Fabrication of Ceramsite Adsorbent from Industrial Wastes for the Removal of Phosphorus from Aqueous Solutions

Journal of Chemistry ◽

10.1155/2020/8036961 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Yue Yin ◽

Gaoyang Xu ◽

Linlin Li ◽

Yuxing Xu ◽

Yihan Zhang ◽

...

Keyword(s):

Adsorption Capacity ◽

Phosphorus Removal ◽

High Efficiency ◽

Column Experiment ◽

Industrial Wastes ◽

Phosphorus Concentration ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Solution Ph ◽

Phosphorus Adsorption

A more applicable adsorbent was fabricated using industrial wastes such as red mud, fly ash, and riverbed sediments. The heavy metal inside the raw materials created metal hydroxy on the adsorbent surface that offered elevated adsorption capacity for phosphorus. The required equilibrium time for the adsorption is only 10 min. The theoretical maximum adsorption capacity of the adsorbent was 9.84 mg·g−1 inferred from the Langmuir adsorption isotherm. Higher solution pH favored phosphorus adsorption. Kinetics study showed that the adsorption could be better fitted by the pseudo-second-order kinetic model. The presence of coexisting anions had no significant adverse impact on phosphorus removal. The speciation of the adsorbed phosphorus indicated that the adsorption to iron and aluminum is the dominating adsorption mechanism. Moreover, a dynamic adsorption column experiment showed that, under a hydraulic time of 10 min, more than 80% of the phosphorus in the influent was removed and the surplus phosphorus concentration was close to 0.1 mg L−1. The water quality after adsorption revealed its applicability in real treatment. Consequently, the adsorbent synthesized from industrial wastes is efficient and applicable due to the high efficiency of phosphorus removal and eco-friendly behavior in solutions.

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