scholarly journals Lignocellulose@ Activated Clay Nanocomposite with Hierarchical Nanostructure Enhancing the Removal of Aqueous Zn(II)

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1710 ◽  
Author(s):  
Xiaotao Zhang ◽  
Yinan Hao ◽  
Zhangjing Chen ◽  
Yuhong An ◽  
Wanqi Zhang ◽  
...  
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Weight Ratio ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Hierarchical Nanostructure ◽  
Desorption Temperature ◽  
Desorption Time ◽  
Adsorption Temperature ◽  
Hcl Concentration

A lignocellulose@ activated clay (Ln@AC) nanocomposite with a hierarchical nanostructure was successfully synthesized by the chemical intercalation reaction and applied in the removal of Zn(II) from an aqueous solution. Ln@AC was characterized by N2 adsorption/desorption isotherms and X-Ray Diffraction (XRD), scanning Electron Microscope (SEM), transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis, and the results indicate that an intercalated–exfoliated hierarchical nanostructure was formed. The effects of different adsorption parameters on the Zn(II) removal rate (weight ratio of Ln to AC, Ln@AC dosage, initial Zn(II) concentration, pH value, adsorption temperature, and time) were investigated in detail. The equilibrium adsorption capacity reached 315.9 mg/g under optimal conditions (i.e., the weight ratio of Ln to AC of 3:1, Ln@AC dosage of 1 g/L, initial Zn(II) concentration of 600 mg/L, pH value of 6.8, adsorption temperature of 65 °C, and adsorption time of 50 min). The adsorption process was described by the pseudo-second-order kinetic model, Langmuir isotherm model, and the Elovich model. Moreover, Zn(II) could be easily eluted by HCl, and the effects of HCl concentration, desorption temperature, and ultrasonic desorption time on desorbed amount were tested. Desorption studies revealed that with an HCl concentration of 0.25 mol/L, desorption temperature of 70 °C, and ultrasonic desorption time of 20 min, the maximum desorption capacity and efficiency were achieved at 202.5 mg/g and 64.10%, respectively. Regeneration experimental results indicated that the Ln@AC exhibited a certain recyclable regeneration performance. Due to such outstanding features, the novel Ln@AC nanocomposite proved to have great adsorption potential for Zn(II) removal from wastewater, and exhibited an extremely significant amount of adsorbed Zn(II) when compared to conventional adsorbents.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

Nano-ZrO2/TiO2 Impregnated Orange Wood Sawdust and Peach Stone Shell Adsorbents for Cr (VI) Removal

2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan
Keyword(s):  
Contact Time ◽  
Ph Value ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Wood Sawdust ◽  
Adsorption Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Equilibrium Status

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.

Synthesis and Characterization of Zeolite X Obtained from Coal Gangue for Adsorption of Cu2+

2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Copper Ions ◽  
Removal Rate ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Zeolite X ◽  
Initial Ph

China is a big coal producing country, there are a lot of coal gangue piled up. The zeolite X was synthesized by alkali melting and hydrothermal method based on the coal gangue from Chifeng city, Inner Mongolia. The obtained zeolite X sample is characterized by X-ray diffraction, SEM, EDS spectrum and IR which showed the X zeolite is an octahedral structure with complete crystal shape and uniform grain size. The results of BET showed the specific surface area of zeolite X is 354.8 m2/g and the minimum pore size is 3.8 nm which indicated that the zeolite X belongs to mesoporous materials. The adsorption conditions of the zeolite X adsorbent on copper ions were optimized. A solution containing Cu2+ ions with an initial concentration of 300 mg/L was added to the zeolite X with a dosage of 0.1 g and the initial pH value of the solution was adjusted to 6. Then the solution was oscillated for 120 min at 225 r/min. The maximum adsorption capacity and removal rate were 148.6 mg/g and 99.1%, respectively. The adsorption mechanism was discussed by adsorption kinetics and thermodynamics. The quasi-second order kinetic equation can be well used to describe the adsorption kinetics of zeolite X to Cu2+ (R2 = 0.9994) and Langmuir can well describe the adsorption behavior of zeolite X to Cu2+ (R2 = 0.9995) which showed the adsorption is a monolayer of chemical adsorption. The adsorption capacity of zeolite X to Cu2+ is about 4.0 times that of coal gangue, indicating that the zeolite X has good adsorption capacity.

Comparative Study of Removal of Cadmium (II) and Chromium (III) Ions from Aqueous Solution Using Low-Cost Biosorbent

2014 ◽  
Vol 12 (1) ◽  
pp. 477-486 ◽  
Author(s):  
Abbas H. Sulaymon ◽  
Ahmed A. Mohammed ◽  
Tariq J. Al-Musawi
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Low Cost ◽  
Order Kinetic ◽  
Cadmium Removal ◽  
Biosorption Capacity ◽  
Biosorption Process ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Batch Biosorption

Abstract This study aims to evaluate the ability of abundant low-cost garden grass to remove cadmium and chromium ions from aqueous solutions. Batch biosorption studies were carried out to examine the biosorption capacity, pH value, temperature, agitation speed, and metal ions concentration. The biosorption process revealed that the garden grass was an effective biosorbent of cadmium and chromium. The maximum chromium and cadmium removal rate was 90 and 80% at pH 4, respectively. FTIR spectroscopy analysis showed that the hydroxyl, amine, and carboxyl groups were the major groups responsible for the biosorption process. The maximum biosorption capacity was 18.19 and 19.4 mg/g for cadmium and chromium, respectively. The biosorption isotherm data fitted well the Langmuir model. Kinetic data were adequately fitted by the pseudo-second-order kinetic model.

Research on Adsorption of Cu2+ in Wastewater by Carbonaceous Adsorbent Made by Sludge

2013 ◽  
Vol 368-370 ◽  
pp. 269-274
Author(s):  
Jin Chuan Gu ◽  
Zi Liang Mei ◽  
Chun Mei Wei ◽  
Hui Yan Wang ◽  
Wen Jun Lin ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Ph Value ◽  
Adsorption Property ◽  
Adsorption Properties ◽  
Order Kinetic ◽  
Adsorption Temperature ◽  
Order Kinetic Model ◽  
Static Conditions ◽  
Kinetics Of ◽  
Carbonaceous Adsorbent

The adsorption property of Cu2+ in aqueous solution by carbonaceous adsorbent made by sludge was studied. Under static conditions, the influences to the adsorption properties by the dosage of adsorbent, adsorption time, concentration of Cu2+, adsorption temperature, pH value, and other factors were systematically studied. The adsorption kinetics of the carbonaceous adsorbent was analyzed, and its adsorption properties were primarily discussed. The research results show that the carbonaceous adsorbent made by sludge has strong removal efficiency of Cu2+; the adsorption process complies with the Fruendlich adsorption isotherm; and the adsorption process can be represented by first-order kinetic model.

scholarly journals Photo-assisted heterogeneous Fenton-like process for treatment of PNP wastewater

2020 ◽  
Vol 10 (1) ◽  
pp. 136-145 ◽  
Author(s):  
F. C. Ban ◽  
X. T. Zheng ◽  
H. Y. Zhang
Keyword(s):  
Kinetic Equation ◽  
Ph Value ◽  
Removal Rate ◽  
Optimum Process ◽  
Process Conditions ◽  
Order Kinetic ◽  
Heterogeneous Fenton ◽  
Solution Ph ◽  
Order Kinetic Model ◽  
Fenton System

Abstract The purpose of this study was to investigate the effect of photo-assisted heterogeneous Fenton on p-nitrophenol (PNP) wastewater treatment by a homemade reactor. Supported Fe-Ce/Al2O3 was used as a catalyst and H2O2 as an oxidant to treat simulated p-nitrophenol wastewater under ultraviolet light. The effects of H2O2 dosage, catalyst dosage, initial solution pH value, reaction temperature and reaction time on the removal rate of p-nitrophenol in a photo-assisted heterogeneous Fenton system were determined. According to the relation between the concentration of each component and time, the relation curve is fitted, and then the kinetic equation is established. Finally, we obtained the optimum process conditions to achieve the PNP wastewater removal rate of 98.7%. The degradation of the photo-assisted heterogeneous Fenton method conforms to the first-order kinetic model, and the kinetic equation is . Therefore, photo-assisted heterogeneous Fenton treatment of PNP wastewater is effective and can be used in the treatment of refractory wastewater.

scholarly journals Preparation of Magnetic g-C3N4/Fe3O4 Composite and Its Application in the Separation of Catechol from Water

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2844 ◽  
Author(s):  
Ruilan Xu ◽  
Yong Peng
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Practical Significance ◽  
Adsorption Parameters ◽  
Adsorption Models ◽  
The Matrix ◽  
Co Precipitation ◽  
Adsorption Desorption ◽  
First Time ◽  
The Magnetic Field

Catechol has strong toxicity and deformity as well as carcinogenicity, and it is difficult to degrade naturally. Therefore, it is of great practical significance to develop efficient adsorbents to separate catechol from water quickly and effectively. In this work, g-C3N4/Fe3O4 magnetic nanocomposites were prepared using g-C3N4 as the matrix by chemical co-precipitation, mixing with Fe2+ and Fe3+ solutions. Then, g-C3N4/Fe3O4 was used, for the first time, as an adsorbent to investigate the removal rate of catechol under different conditions by the magnetic field separation method. The adsorption parameters of the g-C3N4/Fe3O4 nanocomposite were evaluated by the Langmuir and Freundlich adsorption models. The results showed that the g-C3N4/Fe3O4 nanocomposite presented a two-step adsorption behavior and a considerably high adsorption capacity. The removal rate of catechol reached 70% at the dosage of 50 mg, adsorption time of 30 min, and pH value of 6. Five adsorption–desorption cycles demonstrated that the g-C3N4/Fe3O4 material had good stability and reusability.

scholarly journals Preparation of new diatomite–chitosan composite materials and their adsorption properties and mechanism of Hg(II)

2017 ◽  
Vol 4 (12) ◽  
pp. 170829 ◽  
Author(s):  
Yong Fu ◽  
Xiaoxu Xu ◽  
Yue Huang ◽  
Jianshe Hu ◽  
Qifan Chen ◽  
...  
Keyword(s):  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Contact Time ◽  
Ph Value ◽  
Raw Materials ◽  
Removal Rate ◽  
Adsorption Properties ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model

A new composite absorbent with multifunctional and environmental-friendly structures was prepared using chitosan, diatomite and polyvinyl alcohol as the raw materials, and glutaraldehyde as a cross-linking agent. The structure and morphology of the composite absorbent, and its adsorption properties of Hg(II) in water were characterized with Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) measurements and ultraviolet–visible (UV–Vis) spectra. The effect of the pH value and contact time on the removal rate and absorbance of Hg(II) was discussed. The adsorption kinetic model and static adsorption isotherm and regeneration of the obtained composite absorbent were investigated. The results indicated that the removal of Hg(II) on the composite absorbent followed a rapid adsorption for 50 min, and was close to the adsorption saturation after 1 h, which is in accord with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. When the pH value, contact time and the mass of the composite absorbent was 3, 1 h and 100 mg, respectively, the removal rate of Hg(II) on the composite absorbent reached 77%, and the maximum adsorption capacity of Hg(II) reached 195.7 mg g −1 .

MODIFIED AMORPHOUS SiO2 FROM Zr-CONTAINING SILICA RESIDUE: A PROMISING WAY OF RECYCLING USEFUL MATERIALS AS WELL AS REMOVING Cr(VI) FROM WATER

2021 ◽  
pp. 2150022
Author(s):  
YU LIANG ◽  
WANTING CHEN ◽  
HAN ZHANG ◽  
JIMO WANG ◽  
HAO DING ◽  
...  
Keyword(s):  
Ph Value ◽  
Waste Water Treatment ◽  
Order Kinetic ◽  
Solution Ph ◽  
Amorphous Sio2 ◽  
Adsorption Temperature ◽  
Effective Option ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
The Impact

The amorphous SiO2, which is purified from Zr-containing silica residue, was modified by CTAB before the adsorption of Cr(VI). The impact of different variables, such as solution pH value, adsorption time, adsorption temperature, and adsorbent dosage were investigated on the Cr(VI) removal from solution. The results show that the optimal pH value for Cr(VI) adsorption is 3. And 60 min is needed for the adsorption with 10 g/L of modified amorphous SiO2 at [Formula: see text]C. The acquired adsorption isotherm and the adsorption process can be interpreted by Langmuir model and pseudo-second-order kinetic model, respectively. This paper provides an effective option for waste water treatment as well as a way of recycling useful materials from the discarded Zr-containing silica residue.

Kinetic and thermodynamic study of the adsorption of calcium onto sugar beet pulp

2016 ◽  
pp. 565-570
Author(s):  
Huang Qin ◽  
Zhu Si-ming ◽  
Zeng Di ◽  
Yu Shu-juan
Keyword(s):  
Sugar Beet ◽  
Adsorption Equilibrium ◽  
Ph Value ◽  
Hard Water ◽  
Sugar Beet Pulp ◽  
Order Kinetic ◽  
Factors Affecting ◽  
Isotherm Equation ◽  
Equilibrium Data ◽  
Beet Pulp

Sugar beet pulp (SBP) was used as low value adsorbent for the removal of calcium from hard water. Batch experiments were conducted to determine the factors affecting adsorption of the process such as pH value and Ca concentration. The adsorption equilibrium of Ca2+ by the SBP is reached after 100min and a pseudo second-order kinetic model can describe the adsorption process. The initial concentrations of Ca varied from 927 to 1127mgCa2+/L. A dose of 30g/L sugar beet pulp was sufficient for the optimum removal of calcium. The overall uptake of Ca ions by sugar beet pulp has its maximum at pH=8. The adsorption equilibrium data fitted well with the Langmuir adsorption isotherm equation.

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