scholarly journals Green Preparation of Nanoporous Pyrrhotite by Thermal Treatment of Pyrite as an Effective Hg(Ⅱ) Adsorbent: Performance and Mechanism

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 74 ◽  
Author(s):  
Ping Lu ◽  
Tianhu Chen ◽  
Haibo Liu ◽  
Ping Li ◽  
Shuchuan Peng ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Batch Experiments ◽  
Order Model ◽  
Effective Utilization ◽  
Removal Capacity ◽  
Endothermic Process ◽  
Pseudo Second Order ◽  
Natural Pyrite

The removal of Hg(II) from aqueous solutions by pyrrhotite derived from the thermal activation of natural pyrite was explored by batch experiments. The adsorption isotherms demonstrated that the sorption of Hg(II) by modified pyrite (MPy) can be fitted well by the Langmuir model. The removal capacity of Hg(II) on MPy derived from the Langmuir model was determined to 166.67 mg/g. The adsorption process of Hg(II) on MPy was well fitted by a pseudo-second-order model. The sorption of Hg(II) on MPy was a spontaneous and endothermic process. The removal of Hg(II) by MPy was mainly attributed to a chemical reaction resulting in cinnabar formation and the electrostatic attraction between the negative charges in MPy and positive charges of Hg(II). The results of our work suggest that the thermal activation of natural pyrite is greatly important for the effective utilization of ore resources for the removal of Hg(II).

scholarly journals Synthesis Fe3O4/Talc nanocomposite by coprecipition-ultrasonication method and advances in hexavalent chromium removal from aqueous solution

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.

Removal of sunset yellow FCF from aqueous solution using polyethyleneimine-modified MWCNTs

2015 ◽  
Vol 73 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Hejun Gao ◽  
Luanluan Zhang ◽  
Yunwen Liao
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Order Model ◽  
Sunset Yellow ◽  
Multi Wall Carbon Nanotubes ◽  
Initial Ph ◽  
Pseudo Second Order

A novel adsorbent consisting of polyethyleneimine-modified multi-wall carbon nanotubes (PEI-MWCNTs) was synthesized by grafting PEI on the carboxyl MWCNTs. The surface properties of the PEI-MWCNTs were measured by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared, and zeta potential. The adsorption behavior of the PEI-MWCNTs was investigated using sunset yellow FCF as adsorbate. The effects of dosage of adsorbent, the initial pH of solution, contact time and temperature on the adsorption capacity were studied. Then, the kinetics and thermodynamics of the adsorption process were further investigated. Experimental results showed that the adsorption kinetics fitted a pseudo-second-order model and the adsorption isotherms agreed well with the Langmuir model. The adsorption process occurred very fast and the adsorption capacity of PEI-MWCNTs was much higher than that of many of the previously reported adsorbents. Additionally, the plausible adsorption mechanism was discussed.

scholarly journals Adsorption behavior of phosphate on anion-functionalized nanoporous polymer

2015 ◽  
Vol 52 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Zhenyu Wu ◽  
Dasheng Gao ◽  
Ningning Liu
Keyword(s):  
Adsorption Process ◽  
Treatment Method ◽  
Langmuir Model ◽  
Adsorption Behavior ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
N2 Adsorption ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Desorption

An anion-functionalized nanoporous polymer was successfully prepared by quaternary ammonization and anion-exchange treatment method. The polymer was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, N2 adsorption/desorption isotherms and thermogravimetric analysis. Batch experiments were conducted to investigate the adsorption behavior of phosphate on the polymer. The results indicated that the experimental equilibrium data can be well described by the Langmuir model. The maximum adsorption capacity determined from the Langmuir model was 4.92 mg g−1. For kinetic study, the adsorption behavior followed the pseudo-second-order model. Thermodynamic studies indicated that the adsorption process was spontaneous and exothermic.

scholarly journals Removal of methylene blue using activated carbon prepared from date stones activated with NaOH

2019 ◽  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Langmuir Model ◽  
Synthetic Dyes ◽  
Batch Experiments ◽  
Order Model ◽  
X Ray ◽  
Bet Method ◽  
Pseudo Second Order

<p>Synthetic dyes have a hurtful effect on human health and the environment. In this work, activated carbon was produced from date stones for use in elimination of methylene blue charged in aqueous solutions. Before that, the adsorbent was characterized by BET method, SEM, X-ray and TGA. The results of the adsorption kinetics are describe better with the pseudo-second order model (R2= 0.998). Frendlich adsorption isotherm model describe better the experimental data than the Langmuir model. The capacity for methylene blue removal was found to be 163.67 mg/g. Batch experiments studies show that the activated carbon produced as of date stones can be used effectively in the treatment of cationic dyes in aqueous solutions.</p>

scholarly journals Synthesis, characterization and adsorption capacity of lead(II) ions of Fe3O4/C core-shell structure materials

2021 ◽  
Vol 10 (2) ◽  
pp. 43-48
Author(s):  
Dang Le Hai ◽  
Trang Luu Thu ◽  
Hoang Tran Vinh ◽  
Doanh Vu Viet ◽  
Thu Le Dieu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Magnetite Nanoparticles ◽  
Shell Structure ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Core Shell ◽  
Order Model ◽  
Pseudo Second Order ◽  
Core Shell Structure ◽  
Model Expression

Core shell magnetite nanoparticles (Fe3O4@C) as adsorbent for lead ions from aqueous solution were synthesized. The characteristics of the modified materials were analysed. It could also be shown that the adsorption isotherms were well described by the Langmuir model. The kinetic of the adsorption process was found to follow the pseudo-second-order model expression. Thermodynamic studies indicated that the adsorption process was feasible, spontaneous and endothermic.

Adsorption of Dye from Wastewater by Modified Sawdust

2014 ◽  
Vol 1065-1069 ◽  
pp. 3123-3126
Author(s):  
Gang Chao Zhu ◽  
Jian Xin Shou ◽  
Jia Wei Qian ◽  
Hua Zheng Xin ◽  
Mu Qing Qiu
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Langmuir Model ◽  
Ammonium Bromide ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Adsorption Processes ◽  
Endothermic Process ◽  
Pseudo Second Order

In this study, sawdust modified by cetyltimethyl ammonium bromide was applied to adsorb conge red in aqueous solutions. The characteristics of modified sawdust were characterized by Fourier transform infrared spectrum and scanning electron microscopy. The effect of factors, such as pH, contact time, temperature, dosage, and salt concentration, were investigated. The results revealed that the addition of modified sawdust can significantly increase the adsorption capacity of dye. The maximum adsorption capacity of dye on modified sawdust was 109 mg·g-1 at 328K. The adsorption processes were rapid within the first 30 min and reached equilibrium in about 150 min. The adsorption kinetics fitted well with pseudo-second-order model. The pH value of the solution had significant impact on the amount of adsorption. Adsorption isotherm fitted better with the Langmuir model and the adsorption was an endothermic process

scholarly journals Removal of lead(II) ions by an adsorption process with the use of an advanced SiO2/lignin biosorbent

2017 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Przemysław Bartczak ◽  
Tomasz Szatkowski ◽  
Teofil Jesionowski
Keyword(s):  
Experimental Data ◽  
Contact Time ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Order Model ◽  
Multifunctional Material ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Maximal Sorption Capacity ◽  
Optimal Ph

Abstract We demonstrate here that lignin can be successfully combined with silica to create a multifunctional material with considerable sorption capabilities. Experiments were carried out in which a silica/lignin hybrid was used for the removal of lead(II) ions from water solutions. Adsorption kinetics were also determined and preliminary regeneration tests were performed. The effectiveness of the adsorption process depends on the following parameters: contact time of adsorbent and adsorbate (equilibrium times: 5 min for concentration 25 mg/L, 10 min for 50 and 75 mg/L, 60 min for 100 mg/L), pH (optimal pH = 5) and adsorbent mass. The kinetics of the adsorption of lead(II) ions on the SiO2/lignin biosorbent are best described by a pseudo-second-order model. Adsorption isotherms of lead(II) ions were also determined. The experimental data were found to be in agreement with the Langmuir model, and the maximal sorption capacity of the adsorbent with respect to lead(II) was 89.02 mg/g.

4-Sulfonylcalix[6]Arene Modified Fe3O4@Aspergillus Niger Biosorbents for Effective Removal of Uranium(VI) from Aqueous Solutions

2019 ◽  
Vol 19 (11) ◽  
pp. 6978-6986
Author(s):  
Le Li ◽  
Qi Liao ◽  
Chen Cao ◽  
Shuangyang Tang ◽  
Dexin Ding ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Aqueous Solutions ◽  
High Selectivity ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Order Model ◽  
Effective Removal ◽  
Experimental Parameters ◽  
Pseudo Second Order ◽  
Ft Ir

A biosorbent, 4-sulfonylcalix[6]arene modified Fe3O4@Aspergillus Niger (MFSC), was successfully prepared through a two-step route for the effective removal of uranium (U(VI)) from aqueous solutions with high selectivity. The structure of MFSC was characterized by FT-IR, SEM, XRD, TGA and VSM, respectively. The impacts of various experimental parameters were investigated in detail. The results indicated that the biosorption of U(VI) on MFSC was mainly attributed to the electrostatic attraction (91% within 8 hours for U(VI)). The adsorption kinetics and adsorption isotherm of U(VI) were found to follow the pseudo second-order model and to be fitted by the Langmuir model, respectively. The thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. The findings herein highlight the MFSC with high ability for removal of U(VI) from aqueous solutions.

scholarly journals Weathered Sand of Basalt as a Potential Nickel Adsorbent

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1238
Author(s):  
Jae Hong Park ◽  
Jae Kwan Lee
Keyword(s):  
Adsorption Process ◽  
Sem Analysis ◽  
Langmuir Model ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Freundlich Isotherms ◽  
Freundlich Equation ◽  
Low Concentrations ◽  
Pseudo Second Order

The natural mineral, weathered sand of basalt (WSB), was utilized to investigate whether nickel can be removed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were performed to characterize WSB. The effects of various conditions, i.e., contact time, pH, WSB dosage, particle size of WSB, and temperature were analyzed. The experimental data were analyzed by two widely used equations, i.e., Langmuir and Freundlich isotherms. The results obtained revealed that the WSB adsorption process was more consistent with the Langmuir model than the Freundlich equation. The kinetics data fitted well into the pseudo-second-order model. The findings of the present study indicate that WSB could be used for removing nickel from aqueous solution. Moreover, its concentration can be reduced from 1.0 mg/L to ND (not detected, below the device limit <0.01 μg/L) under the optimal condition. Therefore, WSB is considered to be usable as one of the adsorbents for nickel removal in water. In addition, since heavy metals are often present in low concentrations in water, it is considered that WSB can be applied as one of the effective alternatives for removing low-concentration nickel.

Study on the Formaldehyde Adsorption Kinetics of Dry Waters

2014 ◽  
Vol 809-810 ◽  
pp. 907-911
Author(s):  
Jun Long Wang ◽  
Jie Hou ◽  
Ting Jiang ◽  
Yong Jun He ◽  
Yao Dong Liang
Keyword(s):  
Adsorption Kinetics ◽  
High Speed ◽  
Adsorption Process ◽  
Average Diameter ◽  
Adsorption Rate ◽  
Absorption Kinetics ◽  
Order Model ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Formaldehyde Adsorption

Dry waters with an average diameter of 82 μm were prepared by a high speed mixed route. The formaldehyde absorption kinetics of dry waters was investigated by simulating indoor formaldehyde pollution in glass chamber. The results showed that pseudo-second order model could be used to simulate the adsorption process; the adsorption rate was highest in the initial 60 minutes; when the adsorption lasted for 180 minutes, the adsorption reached equilibrium.

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