scholarly journals Hydrothermal Conversion of Red Mud into Magnetic Adsorbent for Effective Adsorption of Zn(II) in Water

2019 ◽  
Vol 9 (8) ◽  
pp. 1519 ◽  
Author(s):  
Wenqing Dong ◽  
Kun Liang ◽  
Yanyi Qin ◽  
Huijia Ma ◽  
Xuan Zhao ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Adsorption Capacity ◽  
Red Mud ◽  
Maximum Adsorption Capacity ◽  
Magnetic Adsorbent ◽  
Hydrothermal Route ◽  
Hydrothermal Temperature ◽  
Facile Hydrothermal Route ◽  
Average Distribution ◽  
The Aluminum Industry

Red mud, a Fe-rich waste generated from the aluminum industry, was recovered as an adsorbent for wastewater treatment. The separation process of red mud from water after adsorption, including centrifugation and filtration, was complicated. This study demonstrated an alternative option to recycle red mud for preparing magnetic adsorbent via a facile hydrothermal route using ascorbic acid as reductant. Red mud is weakly magnetized and consists of andradite, muscovite, hematite, and cancrinite. After hydrothermal treatment, andradite in red mud was reductively dissolved by ascorbic acid, and transformed into magnetite and morimotoite. With increasing hydrothermal temperature, the dissolution of andradite accelerated, and the crystallite size of magnetite increased. When the hydrothermal temperature reached 200 °C, the prepared adsorbent P-200 showed a desirable saturation magnetization of 4.1 Am2/kg, and could be easily magnetically separated from water after adsorption. The maximum adsorption capacity of P-200 for Zn2+ was 89.6 mg/g, which is eight-fold higher than that of the raw red mud. The adsorption of Zn2+ by P-200 fitted the Langmuir model, where cation exchange was the main adsorption mechanism. The average distribution coefficient of Zn2+ at low ppm level was 16.81 L/g for P-200, higher than those of the red mud (0.3 L/g) and the prepared P-120 (1.48 L/g) and P-270 (5.48 L/g), demonstrating that P-200 had the best adsorption capacity for Zn2+ and can be served as a practical adsorbent for real-world applications. To our knowledge, this is the first study to report the conversion of red mud into a magnetic adsorbent under mild conditions.

Synthesis of Calcium Silicate Hydrate Compounds From Wet Flue Gas Desulfurization (FGD) Waste

2020 ◽  
Vol 1 (2) ◽  
pp. 88-95
Author(s):  
Denise Alves Fungaro ◽  
Lucas Caetano Grosche ◽  
Juliana de Carvalho Izidoro
Keyword(s):  
Adsorption Capacity ◽  
Flue Gas ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Flue Gas Desulfurization ◽  
Maximum Adsorption Capacity ◽  
Fusion Temperature ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Wide Range

In this study Calcium silicate hydrate based products (CSHP) were synthesized from wet flue gas desulfurization waste (FGD) by alkali fusion followed by hydrothermal treatment. The effect of various factors on the formation of products, such as mineralizing agent, fusion temperature and time, crystallization time and addition of Ca and Si were studied as well as the conditions optimized. The FGD and synthesized materials were characterized by using X-Ray (XRD), Scanning Electron Microscope (SEM), X-ray fluorescence (XFR), among other methods. A fusion temperature of 600 °C with NaOH, fusion duration of 1 h, and a subsequent hydrothermal temperature of 100 °C for a reaction of 24 h were found to be the optimal conditions. In these synthesis conditions, CSHP containing tobermorite and Al-tobermorite was the major phases. The synthesized CSHP revealed high selective uptake for Cs+ in water. The maximum adsorption capacity of Cs+ onto the synthesized material, as calculated from the Langmuir model, was 1949 µmol g-1. The performance on the Cs+ removal in the presence of high Na+ contents was also evaluated. The adsorbent material showed a high Cs+ adsorption capacity in deionized water and a decrease of 56% and 62% in saturated media with the Na+ ions and seawater, respectively. Therefore, CSHP as a higher value-added product can be obtained from a by-product of a coal-fired power plant, which has wide range applications, including for Cs+ removal from wastewater.

Facile synthesis of magnetic Fe3O4/CeCO3OH composites with excellent adsorption capability for small cationic dyes

RSC Advances ◽  
2015 ◽  
Vol 5 (114) ◽  
pp. 94397-94404 ◽  
Author(s):  
Keyan Li ◽  
Fanfan Chai ◽  
Yongqin Zhao ◽  
Xinwen Guo
Keyword(s):  
Adsorption Capacity ◽  
Cationic Dyes ◽  
Maximum Adsorption Capacity ◽  
Facile Synthesis ◽  
Hydrothermal Route ◽  
One Step ◽  
Adsorption Capability ◽  
Magnetic Fe3o4

A magnetic Fe3O4/CeCO3OH composite prepared through a one-step hydrothermal route exhibits maximum adsorption capacity of 666.2 mg g−1 for MB.

scholarly journals Selective adsorption behavior of Cd2+ imprinted acrylamide-crosslinked-poly(alginic acid) magnetic polymers: fabrication, characterization, adsorption performance and mechanism

2020 ◽  
Author(s):  
Zuyu Li ◽  
Shuangzhen Guo ◽  
Da Li ◽  
Lihua Zang
Keyword(s):  
Metal Ions ◽  
Adsorption Capacity ◽  
Alginic Acid ◽  
Selective Adsorption ◽  
Physical Adsorption ◽  
Maximum Adsorption Capacity ◽  
Magnetic Adsorbent ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
The Impact

Abstract Poly(acrylamide) grafted and glutaraldehyde-crosslinked alginic acid nano-magnetic adsorbent (AAMA) was prepared by selecting Cd2+ as a template ion. Scanning electron microscope (SEM), Thermo-gravimetric analyzer (TGA), Vibrating sample magnetometer (VSM) and Infrared Spectroscopy (IR)were used to characterize the morphology and structure of AAMA. The adsorption of AAMA for different metal ions was compared and the impact of various factors for adsorption of Cd2+ was systematically investigated. These results suggested that the AAMA was the aggregates of Fe3O4 nanoparticles with a diameter of about 50–100 nm. and had selectivity for Cd2+ adsorption. The maximum adsorption capacity for Cd2+ is 175 mg/g at pH 5.0 and 303 K. The experimental data were well described by the Langmuir isotherm model and pseudo-second-order model. The parameters of adsorption thermodynamics concluded that the adsorption progress is spontaneous and endothermic in nature. The parameters of adsorption activation energy suggested that there is physical adsorption and chemisorption on the adsorption of metal ions. AAMA could be regenerated by EDTA and still keep 71% adsorption capacity in the fifth consecutive adsorption-regeneration cycle. Therefore, AAMA would be useful as a selective and high adsorption capacity nano-magnetic adsorbent in the removal of Cd2+ from wastewater.

scholarly journals REMOVAL OF THE REACTIVE REMAZOL BLACK B AND REMAZOL RED FROM AQUEOUS SOLUTIONS BY ADSORPTION ONTO TREATED RESIDUE FROM THE ALUMINUM INDUSTRY

2018 ◽  
Vol 48 (2) ◽  
pp. 101-106
Author(s):  
T. C. SILVA ◽  
T. J.M. FRAGA ◽  
M. CARVALHO ◽  
V. L. SILVA ◽  
M. A. DA MOTTA
Keyword(s):  
Adsorption Capacity ◽  
Aluminum Industry ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Adsorption Efficiency ◽  
Solution Ph ◽  
Remazol Black B ◽  
Remazol Red ◽  
The Aluminum Industry ◽  
Remazol Black

 In this paper, the use of a clay residue as an adsorbent of the Remazol Black B (RB) and Remazol Red RB133 (RR) is studied. The residue is generated in a large amount on the Alluminum industry, especially the Arconic Alumínio S/A, Itapissuma, Pernambuco State. The thermally treated residue behavior was studied by performing a kinetic and equilibrium experiments. The variables evaluated in all experiments were the adsorption capacity (q) and adsorption efficiency (%). Adsorption experiments were performed at environmental conditions, with 50 mL of dye solution, with controlled steering speed, solution pH and adsorbent amount. In the kinetic studies was verified that for RB and RR, the system achieves the equilibrium state after 5 min. In the equilibrium, both reactive dyes obtained their maximum adsorption capacity (qm) with 1.0g of adsorbent and pH 4.0 and 6.5; with qm 0.98 mg·g-1 and 6.88 mg·g-1 for the RB and RR, respectively.

scholarly journals Use of red mud activated at different temperatures as a low cost adsorbent of reactive dye

2021 ◽  
Author(s):  
Maria Lucia Pereira Antunes ◽  
Fabiano Tomazini Conceição ◽  
Guillermo Rafael Beltran Navarro ◽  
Alexandre Martins Fernandes ◽  
Steven Frederick Durrant
Keyword(s):  
Thermal Treatment ◽  
Adsorption Capacity ◽  
Red Mud ◽  
Textile Industry ◽  
Low Cost ◽  
Waste Product ◽  
Reactive Dye ◽  
Maximum Adsorption Capacity ◽  
Different Temperatures ◽  
Acidic Conditions

ABSTRACT Red mud, a waste product generated during alumina extraction from bauxite, could be used as a low-cost adsorbent. Here, the effect of thermal treatment on the adsorption of Reactive Blue 19 (RB19) dye by red mud was compared with the adsorption capacity of untreated red mud. Thermal treatment of red mud at 500°C results in an increase in adsorption capacity from 357 mg g-1 (untreated red mud) to 416 mg g-1, under acidic conditions. Red mud samples thermally treated at 600°C and 800°C show a reduction in adsorption capacity, however, falling to 337 mg g-1, in acid medium. The change in the maximum adsorption capacity of red mud to RB19 following thermal treatment is associated with specific surface area. Red mud subjected to 500°C can be used for the treatment of water and wastewaters with a higher efficiency than untreated red mud, thus finding possible application in the textile industry.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Adsorption and Catalysis of Orange II from Wastewater by Inorganic-Organic-Bentonite

2011 ◽  
Vol 340 ◽  
pp. 236-240
Author(s):  
Jian Feng Ma ◽  
Jian Ming Yu ◽  
Bing Ying Cui ◽  
Ding Long Li ◽  
Juan Dai
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Dye Removal ◽  
Maximum Adsorption Capacity ◽  
Orange Ii ◽  
Acid Dye ◽  
Secondary Pollution ◽  
Organic Bentonite ◽  
Maximum Removal

Inorganic-organic-bentonite was synthesized by modification of bentonite by Hydroxy-iron and surfactant, which could be applied in dye removal by adsorption and catalysis. The removal of acid dye Orange II was studied at various factors such as time and pH of solution. The results showed that the inorganic-organic-bentonite could efficiently remove the dye with efficiency of 96.22%. The maximum adsorption capacity is 76 mg/g. The pH of solution has significant effect on both adsorption and catalysis. When pH was 4, the maximum removal efficiency of adsorption and catalysis were 97.57% and 87.23%, respectively. After degradation, the secondary pollution was diminished and the bentonite could be reused.

scholarly journals Adsorptive and Coagulative Removal of Trace Metals from Water Using Surface Modified Sawdust-Based Cellulose Nanocrystals

J ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 193-205
Author(s):  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Taile Leswifi ◽  
Maurice S. Onyango
Keyword(s):  
Trace Metals ◽  
Adsorption Capacity ◽  
Cellulose Nanocrystals ◽  
Inductively Coupled Plasma ◽  
Electrostatic Interactions ◽  
Natural Waters ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Major Drawback ◽  
Surface Modified

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

scholarly journals Characterizing Bacterial Cellulose Produced byKomagataeibacter sucrofermentans H-110 on Molasses Medium and Obtaining a Biocomposite Based on It for the Adsorption of Fluoride

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1422
Author(s):  
Viktor V. Revin ◽  
Alexander V. Dolganov ◽  
Elena V. Liyaskina ◽  
Natalia B. Nazarova ◽  
Anastasia V. Balandina ◽  
...  
Keyword(s):  
Composite Material ◽  
Adsorption Capacity ◽  
Bacterial Cellulose ◽  
Functional Materials ◽  
Degree Of Crystallinity ◽  
Maximum Adsorption Capacity ◽  
Fluoride Ions ◽  
Sorption Ability ◽  
Wide Range ◽  
Biocomposite Material

Currently, there is an increased demand for biodegradable materials in society due to growing environmental problems. Special attention is paid to bacterial cellulose, which, due to its unique properties, has great prospects for obtaining functional materials for a wide range of applications, including adsorbents. In this regard, the aim of this study was to obtain a biocomposite material with adsorption properties in relation to fluoride ions based on bacterial cellulose using a highly productive strain of Komagataeibacter sucrofermentans H-110 on molasses medium. Films of bacterial cellulose were obtained. Their structure and properties were investigated by FTIR spectroscopy, NMR, atomic force microscopy, scanning electron microscopy, and X-ray structural analysis. The results show that the fiber thickness of the bacterial cellulose formed by the K. sucrofermentans H-110 strain on molasses medium was 60–90 nm. The degree of crystallinity of bacterial cellulose formed on the medium was higher than on standard Hestrin and Schramm medium and amounted to 83.02%. A new biocomposite material was obtained based on bacterial cellulose chemically immobilized on its surface using atomic-layer deposition of nanosized aluminum oxide films. The composite material has high sorption ability to remove fluoride ions from an aqueous medium. The maximum adsorption capacity of the composite is 80.1 mg/g (F/composite). The obtained composite material has the highest adsorption capacity of fluoride from water in comparison with other sorbents. The results prove the potential of bacterial cellulose-based biocomposites as highly effective sorbents for fluoride.

scholarly journals Full Factorial Design for Gold Recovery from Industrial Solutions

Toxics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 111
Author(s):  
Maria Mihăilescu ◽  
Adina Negrea ◽  
Mihaela Ciopec ◽  
Petru Negrea ◽  
Narcis Duțeanu ◽  
...  
Keyword(s):  
Factorial Design ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Design Method ◽  
Precious Metals ◽  
Gold Recovery ◽  
Maximum Adsorption Capacity ◽  
Gold Concentration ◽  
Commercial Resin

Gold is one of the precious metals with multiple uses, whose deposits are much smaller than the global production needs. Therefore, extracting maximum gold quantities from industrial diluted solutions is a must. Am-L-GA is a new material, obtained by an Amberlite XAD7-type commercial resin, functionalized through saturation with L-glutamic acid, whose adsorption capacity has been proved to be higher than those of other materials utilized for gold adsorption. In this context, this article presents the results of a factorial design experiment for optimizing the gold recovery from residual solutions resulting from the electronics industry using Am-L-GA. Firstly, the material was characterized using atomic force microscopy (AFM), to emphasize the material’s characteristics, essential for the adsorption quality. Then, the study showed that among the parameters taken into account in the analysis (pH, temperature, initial gold concentration, and contact time), the initial gold concentration in the solution plays a determinant role in the removal process and the contact time has a slightly positive effect, whereas the pH and temperature do not influence the adsorption capacity. The maximum adsorption capacity of 29.27 mg/L was obtained by optimizing the adsorption process, with the control factors having the following values: contact time ~106 min, initial Au(III) concentration of ~164 mg/L, pH = 4, and temperature of 25 °C. It is highlighted that the factorial design method is an excellent instrument to determine the effects of different factors influencing the adsorption process. The method can be applied for any adsorption process if it is necessary to reduce the number of experiments, to diminish the resources or time consumption, or for expanding the investigation domain above the experimental limits.

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