scholarly journals Improvement of dyes removal from aqueous solution by Nanosized cobalt ferrite treated with humic acid during coprecipitation

2019 ◽  
Vol 9 (4) ◽  
pp. 281-298 ◽  
Author(s):  
Shaimaa M. Ibrahim ◽  
Abdelrahman A. Badawy ◽  
Hisham A. Essawy
Keyword(s):  
Humic Acid ◽  
Active Sites ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Cobalt Iron ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Co Precipitation

Abstract Highly effective novel adsorbent [CoFe2O4-humic acid(HA)] was synthesized by co-precipitation technique at pH 6 (H6) and pH 8 (H8). XRD, SBET and Zeta-potential measurements were used to study the physicochemical properties of the prepared nanoparticles. XRD results showed that the chemical treatment of CoFe2O4 by HA causes the appearance of carbon as new active sites for adsorption process. Batch adsorption tests were achieved to eliminate anionic remazole-red (RR-133) and cationic methylene blue (MB) dyes. The obtained data showed that H6 and H8 solids calcined at 300 and 500 °C have higher adsorption rate for removing of dye than unmodified cobalt iron mixed oxide. The removal reached 100% after a period of dye contact time 2 min and 30 min for RR and MB, respectively. The uptake of RR and MB was much affected by the pH of dye solution. The pseudo-second-order kinetic model was the most fitted well and the adsorption process followed the Langmuir isotherm model. The adsorption of dye on adsorbent was chemisorption process. The as-prepared adsorbents can be regenerated and reused four times for both dyes. The efficiency of the prepared nano-samples and durability as adsorbent were accomplished. Graphic abstract

Adsorption of Cu(II), Ni(II) and Zn(II) ions by nano kaolinite: Thermodynamics and kinetics studies

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Adsorption Process ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

An easy route for preparation emulsion of kaolinite (Al2Si2O5.4H2O) from Sweileh sand deposits, west Amman, Jordan by hydrochloric acid under continuous stirring for 4 h at room temperature was performed and nano kaolinite powder was used as an adsorbent for the removal of Cu(II), Zn(II) and Ni(II) ions. Nano kaolinite was characterized by XRD, FT-IR and SEM techniques. Effect of pH, adsorbent dose, initial metal ion concentration, contact time and temperature on adsorption process was examined. The negative values of ΔGo and the positive value of ΔHo revealed that the adsorption process was spontaneous and endothermic. The Langmuir isotherm model fitted well to metal ions adsorption data and the adsorption capacity. The kinetic data provided the best correlation of the adsorption with pseudo-second order kinetic model. In view of promising efficiency, the nano kaolinite can be employed for heavy metal ions adsorption.

scholarly journals Novel Ag/Kaolin Nanocomposite as Adsorbent for Removal of Acid Cyanine 5R from Aqueous Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Saeedeh Hashemian ◽  
Mohammad Reza Shahedi
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Alkaline Condition ◽  
Order Kinetic ◽  
Nano Composite ◽  
Order Kinetic Model ◽  
Endothermic Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Ag/kaolin nanocomposite was prepared by reduction of Ag+ion with ethanol at alkaline condition on kaolin surface. Nanocomposite was characterized by FTIR, XRD, TEM, and BET methods. Results showed the Ag/kaolin composite has particle size 50 nm. The surface area was increased from kaolin to Ag/kaolin from 1.0215 to 7.409 m2 g−1, respectively. Ag/kaolin nanocomposite was used for adsorption of acid cyanine 5R (AC5R) from aqueous solution. The effect of parameters such as contact time, pH, and mass of nano composite has been investigated. The maximum percentage of adsorption of AC5R was found at pH 3 and contact time of 60 min. The higher percentage removal of AC5R by Ag/kaolin than kaolin can be attributed to catalytic activity of Ag on the surface of kaolin. The experimental data was fitted by pseudo-second-order kinetic model. The adsorption isotherm data could be well interpreted by Langmuir isotherm model. From the results of thermodynamic study, the adsorption process of AC5R onto Ag/kaolin nanocomposite was spontaneous and endothermic process. The process is clean and safe for purifying of water pollution.

Preparation of novel porous Al2O3-SiO2 nanocomposites via solution-freeze-drying-calcination method for the efficient removal of uranium in solution

2021 ◽  
Author(s):  
Maoling Wu ◽  
Ling Ding ◽  
Jun Liao ◽  
Yong Zhang ◽  
Wenkun Zhu
Keyword(s):  
Adsorption Process ◽  
Interaction Mechanism ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Calcination Method ◽  
Adsorption Desorption

Abstract In this work, the efficient extraction of uranium in solution using Al2O3-SiO2-T was reported. Kinetics and isotherm models indicated that the removal process of uranium onAl2O3-SiO2-T accorded with pseudo-second-order kinetic model and Langmuir isotherm model, which showed that the adsorption process was a uniform mono-layer chemical behavior. The maximum adsorption capacity of Al2O3-SiO2-T reached 738.7 mg g-1, which was higher than AlNaO6Si2 (349.8 mg g-1) and Al2O3-SiO2-NT (453.1 mg g-1), indicating that the addition of template could effectively improve the adsorption performance of Al2O3-SiO2 to uranium. Even after five cycles of adsorption-desorption, the removal percentage of uranium on Al2O3-SiO2-T remained 96%. Besides, the extraction efficiency of uranium on Al2O3-SiO2-T was 72.5% in simulated seawater, which suggested that the Al2O3-SiO2-T was expected to be used for uranium extraction from seawater. Further, the interaction mechanism between Al2O3-SiO2-T and uranium species was studied. The results showed that the electrostatic interaction and complexation played key roles in the adsorption process of Al2O3-SiO2-T to uranium.

scholarly journals Kinetics of adsorption of methylene blue onto activated kolanut pod

2021 ◽  
Vol 12 (2) ◽  
pp. 156-162
Author(s):  
A.S. Muhammad ◽  
M.A. Abdurrahman
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Kinetics Of Adsorption ◽  
Initial Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Calculated Amount

A batch adsorption process was carried out by optimizing, the effect of contact time (10min to 180min) and initial concentration (5mg/l to150mg/l). The adsorbent was characterized using FTIR spectra and SEM, and the result obtained showed shifting and disappearance of peaks after adsorption. The results of the adsorption kinetics, which includes the correlation coefficient 0.9771 and the agreement between the amount adsorbed experimentally (1.472mg/g) and the calculated amount absorbed(1.196mg/g) revealed that MB was adsorbed satisfactory according to the pseudo second-order kinetic model.

scholarly journals Modified Cenospheres as an Adsorbent for the Removal of Disperse Dyes

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Markandeya Tiwari ◽  
S. P. Shukla ◽  
D. Mohan ◽  
D. S. Bhargava ◽  
G. C. Kisku
Keyword(s):  
Adsorption Process ◽  
Low Cost ◽  
Agitation Speed ◽  
Disperse Dyes ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorbate Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorbent Dose

The main objective of this investigation was to use modified cenospheres for the removal of disperse blue 79:1 (DB) and disperse orange 25 (DO) dyes from aqueous solution by batch adsorption process under different conditions (pH, adsorbent dose, adsorbate concentration, agitation speed, contact time, and temperature). Modified cenosphere was capable of removing up to 78% of DB and 81% of DO dyes from aqueous solutions of 40 mg/L dyes concentration. The investigated data was explained by the Langmuir isotherm. The experimental data were found to follow the pseudo-second-order kinetic model. The results of this study suggested that modified cenospheres could be used as a low-cost alternative to expensive adsorbents like activated carbon in wastewater treatment for the removal of disperse dyes.

Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun
Keyword(s):  
Tall Fescue ◽  
Adsorption Process ◽  
Exothermic Reaction ◽  
Equilibrium Concentration ◽  
Black Soil ◽  
Adsorption Behavior ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

Adsorption of Zn(II) from Aqueous Solutions by Thiol-Functionalized MCM-48

2011 ◽  
Vol 413 ◽  
pp. 148-153 ◽  
Author(s):  
Xue Na Hu ◽  
Ya Han ◽  
Jia Yan Li ◽  
Jun Yan Wu ◽  
Jian Rong Chen ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Pluronic P123 ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Poly Ethylene Oxide ◽  
Ft Ir ◽  
Poly Ethylene ◽  
Poly Propylene

Thiol-functionalized MCM-48 (SH-MCM-48) was synthesized by co-condensation method, with co-templates of cetyltrimethylammonium bromide (CTAB) and nonionic poly (ethylene oxide)–poly (propylene oxide)–poly (ethylene oxide) triblock copolymer (Pluronic P123). The resulting material was characterized by XRD and FT-IR spectrum. The potential of SH-MCM-48 for adsorption Zn (II) from aqueous solution was examined. Batch adsorption studies were carried out to investigate the effect of experimental parameters including pH, metal ions concentration and adsorption time. The maximum adsorption capacities of Zn (II) onto SH-MCM-48 were 30.12, 34.01 and 38.02 mg g-1 at the temperature of 303, 313 and 323K, respectively. The adsorption kinetics data were found to follow the pseudo-second-order kinetic model, and adsorption isotherms were fitted well with Langmuir and Freundlich models. Moreover, the adsorption thermodynamic parameters (△G0, △H0 and △S0) were measured, and indicated that the adsorption was an exothermic and spontaneous process.

scholarly journals Efficient Congo Red Removal Using Porous Cellulose/Gelatin/Sepiolite Gel Beads: Assembly, Characterization, and Adsorption Mechanism

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3890
Author(s):  
Chenlu Jiao ◽  
Die Liu ◽  
Nana Wei ◽  
Jiannan Gao ◽  
Fan Fu ◽  
...  
Keyword(s):  
Congo Red ◽  
Adsorption Mechanism ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Dye Wastewater ◽  
Step Method ◽  
Gel Beads ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Highly Porous

Porous sustainable cellulose/gelatin/sepiolite gel beads were fabricated via an efficient ‘hydrophilic assembly–floating droplet’ two-step method to remove Congo red (CR) from wastewater. The beads comprised microcrystalline cellulose and gelatin, forming a dual network framework, and sepiolite, which acted as a functional component to reinforce the network. The as-prepared gel beads were characterized using FTIR, SEM, XRD, and TGA, with the results indicating a highly porous structure that was also thermally stable. A batch adsorption experiment for CR was performed and evaluated as a function of pH, sepiolite addition, contact time, temperature, and initial concentration. The kinetics and isotherm data obtained were in agreement with the pseudo-second-order kinetic model and the Langmuir isotherm, with a maximum monolayer capacity of 279.3 mg·g−1 for CR at 303 K. Moreover, thermodynamic analysis demonstrated the spontaneous and endothermic nature of the dye uptake. Importantly, even when subjected to five regeneration cycles, the gel beads retained 87% of their original adsorption value, suggesting their suitability as an efficient and reusable material for dye wastewater treatments.

Biosorption of hexavalent chromium from aqueous solution by polyethyleneimine-modified ultrasonic-assisted acid hydrochar from Sargassum horneri

2020 ◽  
Vol 81 (6) ◽  
pp. 1114-1129 ◽  
Author(s):  
Jun Wang ◽  
Qinglong Xie ◽  
Ao Li ◽  
Xuejun Liu ◽  
Fengwen Yu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Batch Adsorption ◽  
Crosslinking Reaction ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Ultrasonic Assisted ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract In this study, an efficient route to synthesizing polyethyleneimine-modified ultrasonic-assisted acid hydrochar (PEI-USAH) is developed and reported. Ultrasonic irradiation technique was used as surface modification method to shorten the crosslinking reaction for hydrochar and polyethyleneimine (PEI). The PEI-USAH showed an excellent adsorption capacity for Cr(VI) from aqueous solution. The physicochemical properties of this PEI-modified adsorbent were comparatively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis and CNHS analysis. The effects of contact time, initial pH, and biosorbent dose on adsorption capacities were investigated. The batch adsorption experiments showed that PEI-USAH possessed the maximum adsorption capacities of 94.38 mg/g and 330.84 mg/g for initial Cr(VI) concentration of 100 mg/L and 500 mg/L, respectively. Furthermore, this adsorption process could be fitted to Langmuir adsorption and described by the pseudo second order kinetic model. Based on the above findings, PEI-USAH could be used as a potential adsorbent for removal of Cr(VI) from wastewater.

scholarly journals Adsorption removal of Cr(VI) by isomeric FeOOH

2019 ◽  
Vol 80 (2) ◽  
pp. 300-307
Author(s):  
Di Zhang ◽  
Jiaxin Liu ◽  
Shibei Zhu ◽  
Huixin Xiong ◽  
Yiqun Xu
Keyword(s):  
Active Sites ◽  
Correlation Coefficients ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Adsorption Mechanisms ◽  
Ph Values ◽  
Adsorption Removal ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Theoretical Evidence

Abstract The aim of this work is to study the performances of isomeric α-, β-, and γ-FeOOH (goethite, akaganéite and lepidocrocite, including five samples named as Gth1 and Gth2, Aka1 and Aka2, and Lep, respectively) for removing hexavalent chromium (Cr(VI)) from aqueous solutions. The adsorption mechanisms were explored by kinetic and isothermal experiments. Adsorption efficiencies under the different pH values, anions, and the levels of adsorbate and adsorbent were also measured. Results showed that the Cr(VI) adsorption by isomeric FeOOH could be best described by pseudo-second-order kinetic model. The processes of Cr(VI) isothermal adsorption could be greatly fitted by the Langmuir and Freundlich equations with the high correlation coefficients of R2 (>0.92). Also, there were the optimum pH values of 3.0–8.0 for FeOOH to adsorb Cr(VI), and their adsorption capacities were tightly related with the active sites of adsorbents. Cr(VI) adsorptions by these adsorbents were easily influenced by H2PO4–, and then SO42–, while there were little effects by Cl–, CO32– and NO3–. These obtained results could provide a potentially theoretical evidence for isomeric FeOOH materials applied in the engineering treatment of the polluted chromate-rich waters.

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