Adsorption of Congo Red from Aqueous Solutions by Porous Soybean Curd Xerogels

Abstract Soybean curd is a very popular food containing high-quality protein, polyunsaturated fats, vitamins, minerals and other nutrients. This study aims to prepare porous soybean curd xerogels via a vacuum freeze drying method and uses them as adsorbents to remove congo red from aqueous solutions. The morphology and functional groups of the soybean curd xerogels were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The adsorption properties of congo red onto the soybean curd xerogels were carried out through investigating the infl uencing experimental parameters such as the drying method, solution pH, adsorbent dose, contact time and temperature. The results showed that the adsorption isotherm data were fitted well to the Freundlich isotherm. Adsorption kinetics of congo red onto the soybean curd followed the pseudo-second-order kinetic model. The thermodynamic parameters, such as ΔG0, ΔH0 and ΔS0, were also determined.

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The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽

10.3390/min9100626 ◽

2019 ◽

Vol 9 (10) ◽

pp. 626 ◽

Cited By ~ 2

Author(s):

Salah ◽

Gaber ◽

Kandil

Keyword(s):

Aqueous Solutions ◽

Metal Ions ◽

Langmuir Isotherm ◽

Freundlich Isotherm ◽

Order Kinetic ◽

X Ray Diffraction ◽

Solution Ph ◽

X Ray ◽

Order Kinetic Model ◽

Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

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Preparation of Magnetic Composite Polyaniline/Fe3O4−Hydrotalcite and Performance in Removal of Methyl Orange

Adsorption Science & Technology ◽

10.1155/2021/4150073 ◽

2021 ◽

Vol 2021 ◽

pp. 1-18

Author(s):

Thi Tuong An Tran ◽

Huynh Thanh Linh Duong ◽

Thi Thuy Phuong Pham ◽

Tri Nguyen ◽

Thi Dung Nguyen ◽

...

Keyword(s):

Methyl Orange ◽

Organic Dyes ◽

Freundlich Isotherm ◽

Batch Adsorption ◽

Magnetic Composite ◽

Order Kinetic ◽

Solution Ph ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

And Performance

Magnetic composite fabricated from polyaniline and Fe3O4-hydrotalcite (Pan/MHT) was successfully applicated for removal of methyl orange (MO) from wastewater. The structure and properties of Pan/MHT were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer, and Brunauer-Emmett-Teller adsorption isotherm. Adsorption kinetic results indicated that the adsorption process followed pseudosecond-order kinetic model ( R 2 = 0.999 ), MO adsorption onto Pan/MHT was well described by Freundlich isotherm ( R 2 = 0.994 ), and the MO adsorption capacity of 2 Pan/MHT obtained the highest with Q e = 156.25 mg / g . Batch adsorption experiments were carried out using magnetic composite with the effects of initial MO concentration, solution pH, and adsorbent dosage. The results revealed that the magnetic Pan/MHT exhibited efficient adsorption of MO in the aqueous solution as a result of the affinity for organic dyes, microporous structure, and suitable surface area for adsorption (15,460 m2/g). The superparamagnetic behavior of Pan/MHT (with H c = 18.56 Oe , M s = 23.38 × 10 − 3 emu / g , and M r = 0.91 × 10 − 3 emu / g ) helps that it could be separated from the solution and performs as an economical and alternative adsorbent to removal and degrade azo dye from wastewater. Pan/MHT was also investigated to reuse after desorption of MO in 0.1 M HCl, and the results show that 2 Pan/MHT can be reused for 4 cycles with Q e = 79.66 mg / g .

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Removal of fluoride from aqueous solution by adsorption onto Kanuma mud

Water Science & Technology ◽

10.2166/wst.2010.472 ◽

2010 ◽

Vol 62 (8) ◽

pp. 1888-1897 ◽

Cited By ~ 8

Author(s):

Nan Chen ◽

Zhenya Zhang ◽

Chuanping Feng ◽

Miao Li ◽

Rongzhi Chen ◽

...

Keyword(s):

Adsorption Process ◽

Fluoride Concentration ◽

Freundlich Isotherm ◽

Order Kinetic ◽

Solution Ph ◽

Intra Particle Diffusion ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Solid Liquid Interface ◽

Solid Liquid

Kanuma mud, a geomaterial, is used as an adsorbent for the removal of fluoride from water. The influences of contact time, solution pH, adsorbent dosage, initial fluoride concentration and co-existing ions were investigated by batch equilibration studies. The rate of adsorption was rapid with equilibrium being attained after about 2 h, and the maximum removal of fluoride was obtained at pH 5.0–8.0. The Freundlich isotherm model was found to represent the measured adsorption data well. The negative value of the thermodynamic parameter ΔG suggests the adsorption of fluoride by Kanuma mud was spontaneous, the endothermic nature of adsorption was confirmed by the positive ΔH value. The negative ΔS value for adsorbent denoted decreased randomness at the solid/liquid interface. The adsorption process using Kanuma mud followed the pseudo-second-order kinetic model. Fluoride uptake by the Kanuma mud was a complex process and intra-particle diffusion played a major role in the adsorption process. It was found that adsorbed fluoride could be easily desorbed by washing the adsorbent with a solution of pH 12. This indicates the material could be easily recycled.

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Itaconic acid-modified layered double hydroxide as a ‎novel adsorbent for effective removal of Congo red from aqueous solutions

10.21203/rs.3.rs-345643/v1 ◽

2021 ◽

Author(s):

Mohammad Dinari ◽

Shirin Shabani

Keyword(s):

Layered Double Hydroxide ◽

Itaconic Acid ◽

Congo Red ◽

Aqueous Media ◽

Freundlich Isotherm ◽

Second Order ◽

Order Kinetic ◽

Solution Ph ◽

Pseudo Second Order ◽

Double Hydroxide

Abstract Herein, we report the synthesis of Cu-Ca-Al/NO3-based layered double hydroxide through co-precipitation methodology. The prepared layered double hydroxide was then modified with itaconic acid. The physicochemical properties of the prepared materials were studied using Fourier transform-infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric analysis, and nitrogen adsorption/desorption technique. The prepared materials were then applied as novel adsorbents for the removal of Congo red as a model of an anionic dye from aqueous media. To reach maximum adsorption, the effect of parameters including sample solution pH, adsorbent amount, contact time, and initial concentration of Congo red on the adsorption process was investigated. Kinetic studies were also conducted to study the mechanism of adsorption. In this regard, the kinetic models of pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion were studied. The results showed that the adsorption of Congo red onto Cu-Ca-Al-LDH and LDH-ITA adsorbents followed the pseudo-second-order kinetic model. To evaluate the equilibrium adsorption data, different isotherms including Langmuir, Freundlich, and Dubinin-Radushkevich were also applied. The data revealed that the Freundlich isotherm provided the best fit with the equilibrium data of both adsorbents. Maximum adsorption capacities of 81 and 84 mg g− 1 were obtained using Cu-Ca-Al-LDH and LDH-ITA adsorbents, respectively.

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Facile solvothermal synthesis of Fe3O4/magnetic grapefruit peel for adsorptive removal of congo red, humic acid and phosphate from aqueous solutions

Materials Express ◽

10.1166/mex.2020.1610 ◽

2020 ◽

Vol 10 (1) ◽

pp. 37-44 ◽

Cited By ~ 1

Author(s):

Stelgen Inkoua ◽

Herman Loussala Maloko ◽

Mave Motandi Koko ◽

Liangguo Yan

Keyword(s):

Humic Acid ◽

Aqueous Solutions ◽

Congo Red ◽

Solvothermal Reaction ◽

Magnetic Composite ◽

Order Kinetic ◽

Solution Ph ◽

Grapefruit Peel ◽

The Fourier Transform ◽

High Level

An environment-friendly and economical magnetic composite, namely Fe3O4/GP, was produced from grapefruit peel (GP) and ferric chloride via the solvothermal method in one easy step, and was used to remove Congo red (CR), humic acid (HA), and phosphate (P) from aqueous solutions. The Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM) procedures and specific surface area and zeta potential determination were applied to describe the structure of Fe3O4/GP composite. The results shown the Fe3O4 particles, which fabricated during the solvothermal reaction, were distributed evenly on the surface of GP. Then Fe3O4/GP composite also presented a high level of magnetism, and thus could be separated quickly from suspension by an external magnet. The adsorption efficiencies of Fe3O4/GP for CR, HA, and P were 92.88%, 47.45%, and 99.02%, which were found uninfluenced by the initial solution pH and attained the equilibrium state within 10 min. The kinetic and isothermal tests were performed and the data were consistent with the pseudo-second-order kinetic equation and the Freundlich model.

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Evaluation of insoluble xanthate and crosslinked starch-graft-polyacrylamide-co-sodium xanthate for the adsorption of Cu(II) in aqueous solutions

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq141102002t ◽

2015 ◽

Vol 21 (4) ◽

pp. 465-476

Author(s):

Jun Tan ◽

Xiaoyan Wei ◽

Yuxia Ouyang ◽

Rui Liu ◽

Ping Sun ◽

...

Keyword(s):

Aqueous Solutions ◽

Removal Efficiency ◽

Copper Ions ◽

Physical Adsorption ◽

Freundlich Isotherm ◽

Absorption Capacity ◽

Synthetic Wastewater ◽

Ionic Exchange ◽

Order Kinetic ◽

Order Kinetic Model

The effectiveness of insoluble xanthate (ISX) and crosslinked starch-graft-polyacrylamide-co-sodium xanthate (CSAX) for Cu(II) removal from wastewater was evaluated. The two types of xanthates were characterized by SEM, XRD, FTIR, and elemental analysis. Also, the factors influencing adsorption behaviors of copper ions from aqueous solutions were investigated. The results indicated CSAX had higher absorption capacity for Cu(II) than ISX because it contained more N and S. While as far as the removal efficiency was concerned, ISX was better than CSAX for its strong ligand-CSS- groups. The removal efficiency of Cu(II) onto CSAX and ISX increased with the increase in pH. The mechanism for Cu(II) adsorption was ionic exchange for ISX whereas both ion exchange and physical adsorption contributed to adsorption by CSAX. The adsorption kinetics of ISX and CSAX for Cu(II) were favorably described by the pseudo-second-order kinetic model, and the adsorption isotherms were described well with the Freundlich isotherm model. The study with synthetic wastewater showed CSAX was a worthwhile alternative to the traditional ISX only when the wastewater contained both Cu(II) and turbidity.

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Synthesis of carbon dots-assisted MgAl-LDH hollow microspheres with hierarchical structure for the effective removal of Congo red from wastewater

E3S Web of Conferences ◽

10.1051/e3sconf/202126902003 ◽

2021 ◽

Vol 269 ◽

pp. 02003

Author(s):

Zhigang Jia ◽

Cong Han ◽

Rui Chang ◽

Daqing Zhang

Keyword(s):

Congo Red ◽

Carbon Dots ◽

Ostwald Ripening ◽

Order Kinetic ◽

Effective Removal ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Ft Ir ◽

Double Hydroxide

Hierarchical hollow Mg-Al layered double hydroxide microspheres (HHMs) are successfully prepared by hydrothermal treatment in the presence of carbon dots (CDs). Morphology and structure of the as-prepared samples are characterized using XRD, SEM, FT-IR, and TEM techniques. The growth process of HHMs has been investigated in detail, and Ostwald ripening mechanism is suggested for the hierarchical growth of HHMs. Adsorption isotherms and adsorption kinetics of HHMs for congo red (CR) are investigated. Langmuir and Temkin model are more fitted to the experimental data of CR isotherm adsorption. Adsorption kinetic data obeys the pseudo-second-order kinetic model. Moreover, thermodynamic parameters (ΔGo, ΔHo and ΔSo) show that the CR adsorption onto HHMs is an endothermic and spontaneous process. The as-prepared HHMs could be a potential adsorbent for wastewater treatment containing anion dyes.

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Comparative Study of Ni-Zn LHS and Mg-Al LDH Adsorbents of Navy Blue and Yellow F3G Dye

Indonesian Journal of Chemistry ◽

10.22146/ijc.21175 ◽

2018 ◽

Vol 16 (1) ◽

pp. 36 ◽

Cited By ~ 6

Author(s):

Idha Yulia Ikhsani ◽

Sri Juari Santosa ◽

Bambang Rusdiarso

Keyword(s):

Adsorption Capacity ◽

Freundlich Isotherm ◽

Second Order ◽

Isotherm Models ◽

Disperse Dyes ◽

Order Kinetic ◽

Initial Ph ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Pseudo Second Order

Adsorption of disperse dyes from wastewater onto Ni-Zn LHS (layered hydroxide salts) and Mg-Al LDH (layered double hydroxides) has been compared in this study. Effects of initial pH solution, contact time and initial dye concentration were investigated. The ability of the adsorbent to be reused was also studied. The results showed that acidic condition was favorable for the adsorption of each dyes onto both adsorbent. The adsorption kinetics was studied using pseudo-first-order, pseudo-second-order and Santosa’s kinetics models. The experimental data fits well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption of navy blue onto both adsorbent followed Freundlich isotherm adsorption, while yellow F3G followed Langmuir isotherm adsorption. In the application for the adsorption the wastewater containing dyes, Ni-Zn LHS has a better adsorption capacity of 52.33 mg/g than that of Mg-Al LDH that 30.54 mg/g. Calcination of the adsorbent which has already been used increased the adsorption capacity of Mg-Al LDH to 84.75 mg/g, but decreased the adsorption capacity of the Ni-Zn LHS to 42.65 mg/g.

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Removal of Basic Dyes from Aqueous Solutions by Adsorption onto Moroccan Clay (Fez City)

Mediterranean Journal of Chemistry ◽

10.13171/10.13171/mjc8319050803hz ◽

2019 ◽

Vol 8 (3) ◽

pp. 158

Author(s):

Zaitan Hicham ◽

Zineb Bencheqroun ◽

Imane El Mrabet ◽

Mohammed Kachabi ◽

Mostafa Nawdali ◽

...

Keyword(s):

Aqueous Solutions ◽

Nitrogen Adsorption ◽

Textile Dyes ◽

Operating Conditions ◽

Point Of Zero Charge ◽

Order Kinetic ◽

Natural Clay ◽

Solution Ph ◽

Basic Dyes ◽

Order Kinetic Model

The main objective of this study was to investigate the potential of natural clay obtained (from Fez city, Morocco) as an adsorbent for the removal of basic dyes (Astrazon Blue BG and Astrazon Yellow 7GLL) from liquid effluents. Natural clay was characterised using different physical-chemical methods, including nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), pH of the point of zero charge (pHPZC) and Boehm titration method. The clay was tested to remove various textile dyes from the aqueous solution at room temperature. Parameters such as initial dye concentration, solution pH, adsorbent dosages and contact time were performed in a batch system for controlling the operating conditions. Experimental results data indicated that the adsorption process is a fast and spontaneous reaction. A pseudo-second-order kinetic model provides the best fit to the experimental data of BG and YL adsorption onto the natural clay. Theadsorption isotherm data of both the dyes onto the natural clay were fitted well to the Langmuir model. A maximum monolayer adsorption capacity of 101 mg.g-1 for BG and 127 mg.g-1 for YL are obtained at 298.15 K.The results suggest that the natural clay could be used as an inexpensive adsorbent for the removal of the textile dyes from aqueous solutions.

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Removal of Basic Dyes from Aqueous Solutions by Adsorption onto Moroccan Clay (Fez City)

Mediterranean Journal of Chemistry ◽

10.13171/mjc8319050803hz ◽

2019 ◽

Vol 8 (3) ◽

pp. 158-167 ◽

Cited By ~ 4

Author(s):

Zaitan Hicham ◽

Zineb Bencheqroun ◽

Imane El Mrabet ◽

Mohammed Kachabi ◽

Mostafa Nawdali ◽

...

Keyword(s):

Aqueous Solutions ◽

Nitrogen Adsorption ◽

Textile Dyes ◽

Operating Conditions ◽

Point Of Zero Charge ◽

Order Kinetic ◽

Natural Clay ◽

Solution Ph ◽

Basic Dyes ◽

Order Kinetic Model

The main objective of this study was to investigate the potential of natural clay obtained (from Fez city, Morocco) as an adsorbent for the removal of basic dyes (Astrazon Blue BG and Astrazon Yellow 7GLL) from liquid effluents. Natural clay was characterised using different physical-chemical methods, including nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), pH of the point of zero charge (pHPZC) and Boehm titration method. The clay was tested to remove various textile dyes from the aqueous solution at room temperature. Parameters such as initial dye concentration, solution pH, adsorbent dosages and contact time were performed in a batch system for controlling the operating conditions. Experimental results data indicated that the adsorption process is a fast and spontaneous reaction. A pseudo-second-order kinetic model provides the best fit to the experimental data of BG and YL adsorption onto the natural clay. Theadsorption isotherm data of both the dyes onto the natural clay were fitted well to the Langmuir model. A maximum monolayer adsorption capacity of 101 mg.g-1 for BG and 127 mg.g-1 for YL are obtained at 298.15 K.The results suggest that the natural clay could be used as an inexpensive adsorbent for the removal of the textile dyes from aqueous solutions.

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