scholarly journals CH4/N2 Adsorptive Separation on Zeolite X/AC Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Cai Long Xue ◽  
Wen Ping Cheng ◽  
Wen Ming Hao ◽  
Jing Hong Ma ◽  
Rui Feng Li
Keyword(s):  
Adsorption Capacity ◽  
Micropore Volume ◽  
Zeolite X ◽  
Adsorption Selectivity ◽  
Adsorptive Separation ◽  
Capacity Loss ◽  
Pressure Swing ◽  
Polar Functional Groups ◽  
Adsorption Desorption ◽  
The Relationship

A series of zeolite X/activated carbon (AC) composites were prepared from the same starting materials at various activation time. The corresponding modified samples were obtained by being treated with diluted NH4Cl solution. The relationship between porosity development, surface properties, and CH4/N2 adsorption performance was investigated. The increase of micropore volume is beneficial to the improvement of CH4 and N2 adsorption capacity, but more sensitive for CH4. In addition, the polar functional groups of zeolite X/AC composites may enhance CH4 adsorption capacity. More importantly, both developing micropore structure and surface modification contributed to enhance the adsorption selectivity αCH4/N2. As the optimum sample of these studies, HZAC(24) showed CH4 adsorption capacity of 17.3 cm3/g and the highest adsorption selectivity αCH4/N2 of 3.4. The CH4 and N2 adsorption isotherms of all samples can be well fitted by the Langmuir–Freundlich model. HZAC(24) showed an excellent cyclability of adsorption/desorption of CH4 with a neglectable capacity loss after subsequent cycles. Moreover, HZAC(24) displayed relatively rapid adsorption kinetics. These properties of zeolite X/AC composites are essential for the adsorptive separation of CH4 from N2 in the pressure swing adsorption (PSA) process.

scholarly journals Selective and rapid removal of Mo(VI) from water using functionalized Fe3O4-based Mo(VI) ion-imprinted polymer

2020 ◽  
Author(s):  
Lang Wu ◽  
Zhengwei Luo ◽  
Hui Jiang ◽  
Zijian Zhao ◽  
Wenhua Geng
Keyword(s):  
Adsorption Capacity ◽  
Isotherm Model ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Ion Imprinted Polymer ◽  
Imprinted Polymer ◽  
Adsorption Selectivity ◽  
X Ray ◽  
Ion Imprinted ◽  
Adsorption Desorption

Abstract Fe3O4 nanoparticles-based magnetic Mo(VI) surface ion-imprinted polymer (Mo(VI)-MIIP) was elaborated employing 4-vinyl pyridine as a functional monomer. The adsorbent preparation was confirmed by Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, vibrating sample magnetometer, thermogravimetric analysis, and surface area analysis. Batch adsorption experiments displayed that the maximum adsorption capacity of Mo(VI)-MIIP was 296.40 mg g−1 at pH 3, while that of the magnetic non-imprinted polymer (MNIP) was only 147.10 mg g−1. The adsorption isotherm model was well-fitted by the Langmuir isotherm model. The adsorption experiments revealed that Mo(VI)-MIIP reached adsorption equilibrium within 30 min, and the kinetics data fitting showed that the pseudo-second-order kinetics model suitably described the adsorption process. Mo(VI)-MIIP exhibited an excellent adsorption selectivity to Mo(VI) in binary mixtures of Mo(VI)/Cr(VI), Mo(VI)/Cu(II), Mo(VI)/H2PO44-, Mo(VI)/Zn(II), and Mo(VI)/I–, with relative selectivity coefficients toward MNIP of 13.71, 30.27, 20.01, 23.53, and 15.89, respectively. After six consecutive adsorption-desorption cycles, the adsorption capacity of Mo(VI)-MIIP decreased by 9.5% (from 228.4 mg g−1 to 206.7 mg g−1 at initial Mo(VI) concentration of 250 mg L−1), demonstrating its reusability.

scholarly journals Preparation of Polyaniline/Emulsion Microsphere Composite for Efficient Adsorption of Organic Dyes

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 167 ◽  
Author(s):  
Yuanli Liu ◽  
Liushuo Song ◽  
Linlin Du ◽  
Peng Gao ◽  
Nuo Liang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
In Situ Polymerization ◽  
Organic Dyes ◽  
Removal Rate ◽  
Three Dimensional ◽  
Maximum Adsorption Capacity ◽  
Adsorption Selectivity ◽  
Polymeric Microspheres ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Surface-functionalized polymeric microspheres have wide applications in various areas. Herein, monodisperse poly(styrene–methyl methacrylate–acrylic acid) (PSMA) microspheres were prepared via emulsion polymerization. Polyaniline (PANI) was then coated on the PSMA surface via in situ polymerization, and a three-dimensional (3D) structured reticulate PANI/PSMA composite was, thus, obtained. The adsorption performance of the composite for organic dyes under different circumstances and the adsorption mechanism were studied. The obtained PANI/PSMA composite exhibited a high adsorption rate and adsorption capacity, as well as good adsorption selectivity toward methyl orange (MO). The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm. The maximum adsorption capacity for MO was 147.93 mg/g. After five cycles of adsorption–desorption, the removal rate remained higher than 90%, which indicated that the adsorbent has great recyclability. The adsorbent materials presented herein would be highly valuable for the removal of organic dyes from wastewater.

Effect of Surface Area and Micropore Volume of Activated Carbons from Coal by KOH, NaOH and ZnCl2 Treatments on Methane Adsorption

2018 ◽  
Vol 17 (6) ◽  
Author(s):  
Atakan Toprak ◽  
Turkan Kopac
Keyword(s):  
Surface Area ◽  
Activated Carbons ◽  
Micropore Volume ◽  
Industrial Applications ◽  
Methane Adsorption ◽  
Bet Surface Area ◽  
Adsorption Characteristics ◽  
Adsorption Capacities ◽  
Adsorption Desorption ◽  
The Relationship

Abstract This paper investigates the methane adsorption characteristics of activated carbons produced from coal by activation with KOH, NaOH and ZnCl2 treatments at different agent to coal ratios (1:1–6:1) and temperatures (600–800 °C) under N2 flow. CH4 adsorption capacities and desorption behaviors of the activated carbons were examined at 0 °C and 25 °C. The relationship between CH4 adsorption characteristics and surface properties of activated carbons, such as BET surface area determined by N2 adsorption at −196 °C, and micropore volume determined by CO2 adsorption at 0 °C were investigated. Optimal results for CH4 adsorption at 0 °C and 25 °C were obtained for the activated carbon samples obtained with KOH treatment at 800 °C at 4:1 ratio, as 2.67 and 1.12 mmol/g, respectively. The results have shown that CH4 adsorption increased proportionally with micropore volume of activated carbons, whereas BET surface area does not exhibit an exact consistency. CH4 adsorption-desorption isotherms at 25 °C have shown that an increase in mesopore formation caused a decrease in adsorption; but allowed desorption to be reversible. Higher methane adsorption capacities were obtained from activated carbons produced from coal by various treatments in this study than most of the reported results in literature at the similar conditions, indicating the suitability of the evaluated materials for industrial applications of methane storage.

CO2 Capture onto Zeolite 13X and Zeolite 4A by Pressure Swing Adsorption in a Fixed Bed

2014 ◽  
Vol 592-594 ◽  
pp. 1456-1460 ◽  
Author(s):  
Lalhmingsanga Hauchhum ◽  
P. Mahanta
Keyword(s):  
Adsorption Capacity ◽  
Pressure Swing Adsorption ◽  
Fossil Fuels ◽  
Gas Adsorption ◽  
Fixed Bed ◽  
Fuel Gas ◽  
Zeolite 13X ◽  
Zeolite 4A ◽  
Pressure Swing ◽  
Adsorption Desorption

Combustion of fossil fuels is one of the major sources of greenhouse gas CO2, it is therefore necessary to develop technologies that will allow us to utilize the fossil fuels while reducing the emissions of greenhouse gases. Pressure swing adsorption (PSA) is a potential technique for removing CO2from high-pressure fuel gas streams. Zeolites are suitable candidate sorbents for use in the PSA process. Studies of the gas adsorption of CO2onto zeolite 13X and zeolite 4A were conducted at a temperature of 25 °C, 35 °C, 45 °C and 60 °C up to a pressure of 1 bar. The data fitting is accomplished with the Toth and Sips adsorption models which are generally used for micro-porous adsorbents such as zeolites. Moreover, regeneration studies have been conducted in order to verify the possibility of adsorbents reutilization, to determine its CO2adsorption capacity within consecutive cycles of adsorption–desorption. Zeolite with higher surface area showed higher CO2adsorption capacity. There is no full reversibility for the two zeolites.

scholarly journals Preparation of a Novel Lignin Nanosphere Adsorbent for Enhancing Adsorption of Lead

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2704 ◽  
Author(s):  
Chao Liu ◽  
Youming Li ◽  
Yi Hou
Keyword(s):  
Adsorption Capacity ◽  
Chemical Interaction ◽  
Average Diameter ◽  
Lead Ions ◽  
Maximum Adsorption Capacity ◽  
Step Method ◽  
Capacity Loss ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Kinetics And Isotherms

Carboxymethyl lignin nanospheres (CLNPs) were synthesized by a two-step method using microwave irradiation and antisolvent. The morphology and structure of CLNPs were characterized by 31P-NMR, FTIR, and SEM, and the results showed that they had an average diameter of 73.9 nm, a surface area of 8.63 m2 or 3.2 times larger than the original lignin, and abundant carboxyl functional groups of 1.8 mmol/g. The influence of dosage, pH, contact time, and concentration on the adsorption of metal ions onto CLNPs were analyzed, and the maximum adsorption capacity of CLNPs for Pb(II) was found to be 333.26 mg/g, which is significantly higher than other lignin-based adsorbents and conventional adsorbents. Adsorption kinetics and isotherms indicated that the adsorption of lead ions in water onto CLNPs followed the pseudo-second-order model based on monolayer chemisorption mechanism. The main chemical interaction between CLNPs and lead ions was chelation. CLNPs also showed an excellent recycling performance, with only 27.0% adsorption capacity loss after 10 consecutive adsorption–desorption cycles.

Soil and Stream Water Chemistry During Spring Snowmelt

1992 ◽  
Vol 23 (1) ◽  
pp. 13-26 ◽  
Author(s):  
W. H. Hendershot ◽  
L. Mendes ◽  
H. Lalande ◽  
F. Courchesne ◽  
S. Savoie
Keyword(s):  
Stream Water ◽  
Base Cations ◽  
Stream Chemistry ◽  
Stream Water Chemistry ◽  
The Matrix ◽  
Adsorption Desorption ◽  
The Relationship ◽  
Best Fit ◽  
Spring Snowmelt ◽  
Over Time

In order to determine how water flowpath controls stream chemistry, we studied both soil and stream water during spring snowmelt, 1985. Soil solution concentrations of base cations were relatively constant over time indicating that cation exchange was controlling cation concentrations. Similarly SO4 adsorption-desorption or precipitation-dissolution reactions with the matrix were controlling its concentrations. On the other hand, NO3 appeared to be controlled by uptake by plants or microorganisms or by denitrification since their concentrations in the soil fell abruptly as snowmelt proceeded. Dissolved Al and pH varied vertically in the soil profile and their pattern in the stream indicated clearly the importance of water flowpath on stream chemistry. Although Al increased as pH decreased, the relationship does not appear to be controlled by gibbsite. The best fit of calculated dissolved inorganic Al was obtained using AlOHSO4 with a solubility less than that of pure crystalline jurbanite.

scholarly journals Adsorption Capacity and Selectivity of Molecularly Imprinted Polymers towards β-Sitosterol

2019 ◽  
Vol 31 (11) ◽  
pp. 2527-2531
Author(s):  
St. Fauziah ◽  
N.H. Soekamto ◽  
P. Budi ◽  
P. Taba
Keyword(s):  
Adsorption Capacity ◽  
Molecularly Imprinted Polymers ◽  
Solid Phase ◽  
Polymerization Reaction ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Sample Extract ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Isothermal Equation

Molecularly imprinted polymers (MIP) as an adsorbent has been synthesized using β-sitosterol as molecule template on free radical polymerization reaction. The capacity and selectivity of the adsorption from MIP to β-sitosterol was studied in this study. The β-sitosterol concentration in the adsorption-desorption test and the MIP selectivity test were analyzed by UV-visible and HPLC. The MIP obtained from the synthesis results in a high adsorption capacity. Based on the Freundlich adsorption isothermal equation, the adsorption capacity (k) was found to be 1.24 mg/g. The MIP can adsorb 100 % β-sitosterol while cholesterol was only 3 %. The MIP is most selective to β-sitosterol, therefore, has high potential to apply as adsorbent at solid phase extraction method to isolate β-sitosterol from sample extract.

scholarly journals Biochar of Spent Coffee Grounds as Per Se and Impregnated with TiO2: Promising Waste-Derived Adsorbents for Balofloxacin

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2295
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Hagar Morsy
Keyword(s):  
Adsorption Capacity ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Spent Coffee Grounds ◽  
Thermal Stabilities ◽  
Coffee Grounds ◽  
Bet Analysis ◽  
Pseudo Second Order ◽  
Set Up ◽  
Adsorption Desorption

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett-Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.

Removal of Cd(II) from Water System Using Novel Biosorbent Derived from Persimmon Fallen Leaves

2015 ◽  
Vol 1130 ◽  
pp. 685-688
Author(s):  
Rui Yi Fan ◽  
Qing Ping Yi ◽  
Qing Lin Zhang ◽  
Zheng Rong Luo
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Water System ◽  
Raw Material ◽  
Batch Adsorption ◽  
Diospyros Kaki ◽  
Cadmium Metal ◽  
Fallen Leaves ◽  
Adsorption Desorption

A biosorbent was prepared by treating the persimmon (Diospyros kaki Thunb.) fallen leaves with sodium hydroxide (NaOH). The NaOH concentration and stirring period for the preparation of the biosorbent were adjusted to optimise the Cd(I) adsorption capacity of the biosorbents. Removal of highly toxic Cadmium metal ions from water system using the optimal biosorbent named ‘NPFL’ was investigated using a mimic industrial column. The result showed that NPFL could remove Cd(II) in large quantities from aqueous solution with coexisting metal ions. The raw material, NPFL and Cd(II) loaded NPFL were characterized by SEM-EDS. The reusability of NPFL was also studied by batch adsorption-desorption test.

Effect of L-Arginine on the Carbon Microsphere Forming under Hydrothermal Carbonization

2019 ◽  
Vol 41 (1) ◽  
pp. 72-72
Author(s):  
Jilei Liang Jilei Liang ◽  
Mengmeng Wu Mengmeng Wu ◽  
Hongmei Cai Hongmei Cai ◽  
Hao Wang Hao Wang ◽  
Hua Huang Hua Huang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Adsorption Capacity ◽  
Surface Property ◽  
Condensation Reaction ◽  
Hydrothermal Carbonization ◽  
Carbon Microspheres ◽  
N2 Adsorption ◽  
Sem Images ◽  
Ft Ir ◽  
Adsorption Desorption

Carbon microspheres (CMs) with a diameter of 5-10 μm have been synthesized by hydrothermal carbonization of starch and L-arginine. The surface property and structure of CMs were examined by FT-IR spectra, N2 adsorption-desorption isotherms and SEM images. These characterizations indicated that the L-arginine does not connect into the CMs but it promotes the starch hydrolysis and polymerization-condensation reaction of intermediate, which accelerates the formation of CMs and improves the yield in shorter time. The surface property of CMs determines adsorption capacity for acetic acid. By contrast, the porosity resulted from the carbonization at 500 and#176;C dominates the adsorption capacity for acetic acid.

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