scholarly journals Preparation of hydrogel reinforced with bentonite by gamma irradiation for metal absorption

2021 ◽  
Vol 10 (4) ◽  
pp. 48-55
Author(s):  
Tran To Uyen ◽  
Trinh Thi Tu Anh ◽  
Tamikazu Kume ◽  
Cao Dong Vu ◽  
Nguyen Minh Hiep ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Adsorption Process ◽  
Absorption Spectrometry ◽  
Order Model ◽  
Adsorption Capacities ◽  
Dose Concentration ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Aas Method ◽  
Irradiation Technology

A natural-based sodium carboxymethyl cellulose (CMC) hydrogel reinforced with bentonite was prepared by using gamma irradiation technology. This is a novel hydrogel that uses natural polymer to absorb metal ions in wastewater. The influence of dose, concentration of CMC and bentonite on the sorption of hydrogels was investigated by atomic absorption spectrometry (AAS) method. According to the Langmuir isotherm model, the maximum adsorption capacities of CMC/bentonite hydrogel for Cu2+ and Pb2+ were 181.82 mg/g and 204.08 mg/g at room temperature, respectively. The pseudo-second-order model which describes the adsorption process of Cu2+ and Pb2+ was also studied

scholarly journals High Removal Efficiency of Diatomite-Based X Zeolite for Cu2+ and Zn2+

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6525
Author(s):  
Guangyuan Yao ◽  
Yuqiang Liu ◽  
Shuilin Zheng ◽  
Ya Xu
Keyword(s):  
Ion Exchange ◽  
Adsorption Process ◽  
Interface Properties ◽  
Order Model ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
X Zeolite ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetics And Isotherms

Diatomite-based X zeolite was obtained and its crystallinity, morphology, and interface properties were investigated by XRD, BET, SEM, EDS, and XRF. The obtained X zeolite possessed a unique meso-microporous structure and showed good ion exchange properties for Cu2+ and Zn2+. The pseudo-second-order model and Langmuir isotherm model can best describe the adsorption kinetics and isotherms of Cu2+ and Zn2+, respectively. The maximal adsorption capacities of X zeolite for Cu2+ and Zn2+ were 146 and 195 mg/g at 323 K, respectively. Meanwhile, the adsorption process for Cu2+ and Zn2+ were chemical adsorption and ion exchange, respectively. Furthermore, the adsorption data turned out to be an endothermic and spontaneous process. Compared with other reported materials, the adsorption capacity of X zeolite synthesized from diatomite was among the highest. Therefore, it could be a promising adsorbent for the disposal of wastewater that contains metal ions.

scholarly journals Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites

2019 ◽  
Vol 80 (7) ◽  
pp. 1357-1366
Author(s):  
Jianming Liu ◽  
Runying Bai ◽  
Junfeng Hao ◽  
Bowen Song ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Ligand Exchange ◽  
Adsorption Process ◽  
High Adsorption ◽  
Order Model ◽  
Powder Composites ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Level ◽  
Adsorption Desorption

Abstract This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO2-modified Fe3O4 (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH)3, Ce (OH)3, and Fe3O4, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity. The magnetic adsorbent exhibits a high adsorption capacity of 53.72 mg/g, a short equilibrium time of 60 min, and superior selectivity for phosphate. Moreover, the adsorbent strongly depends on the pH during the adsorption process and maintains a large adsorption capacity when the pH level is between 2 and 6. The adsorption of phosphate by the CMIO@PP (1:3) accords with the Langmuir isotherm model, and the adsorption process follows the pseudo-second order model. Meanwhile, adsorption–desorption experiments show that the adsorbent could be recycled a few times and that a high removal efficiency of phosphate from civil wastewater was achieved. Finally, mechanisms show that the adsorption of phosphate by the CMIO@PP (1:3) is mainly caused by electrostatic attraction and ligand exchange.

Adsorptive removal of Rhodamine B from aqueous solution by nanoporous polydivinylbenzene

2017 ◽  
Vol 75 (7) ◽  
pp. 1651-1658 ◽  
Author(s):  
Hongyu Jia ◽  
Ningning Liu
Keyword(s):  
Rhodamine B ◽  
Adsorption Process ◽  
Order Model ◽  
N2 Adsorption ◽  
Adsorptive Removal ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Scanning Electron

Nanoporous polydivinylbenzene (PDVB) material has been successfully prepared via the copolymerization of divinylbenzene monomers. The nanoporous PDVB was characterized through N2 adsorption/desorption isotherms, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The nanoporous PDVB as an adsorbent was applied for the removal of Rhodamine B (RhB). The adsorption behavior of PDVB for the removal of RhB showed that the isotherm data followed the Langmuir isotherm model and the kinetic adsorption obeyed the pseudo-second-order model. Thermodynamic parameters illustrated that the adsorption process was spontaneous and exothermic. Interestingly, the spent nanoporous PDVB has excellent regenerative performance through treating it with ethanol. These results revealed that PDVB might be an excellent adsorbent for the removal of RhB from wastewater.

The Removal of Phosphate by Coal Gangue from Wastewater

2012 ◽  
Vol 209-211 ◽  
pp. 2005-2008 ◽  
Author(s):  
Fang Juan Zhang ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Waste Water ◽  
Adsorption Process ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The feasibility of coal gangue as an adsorbent for phosphate removal from wastewater was investigated. The results showed that the equilibrium data were well fit to Langmuir isotherm model and the maximum adsorption capacity calculated was 2.49 mg/g at 25°C. The adsorption process followed pseudo-second order model. And the practical waste water experiment indecated that the phosphate concentration of real sewage decreased from 0.625mg/L to 0.121mg/L. These results suggested that coal gangue can be used as an adsorbent to removal phosphate from wastewater.

scholarly journals Structuring of ZnTiO3/TiO2 Adsorbents for the Removal of Methylene Blue, Using Zeolite Precursor Clays as Natural Additives

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 898
Author(s):  
Ximena Jaramillo-Fierro ◽  
Silvia González ◽  
Fernando Montesdeoca-Mendoza ◽  
Francesc Medina
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Sol Gel ◽  
Area Measurement ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Surface Area Measurement ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Adsorption is an effective method of removing harmful pollutants from air and water. In the present study, zeolites prepared by sol-gel method from two Ecuadorian clays were combined with precursor clays and the ZnTiO3/TiO2 semiconductor for adsorbing methylene blue (MB) as a water contaminant. The synthesized compounds were characterized using powder X-ray diffraction, X-ray fluorescence, scanning electron microscopy, energy dispersive X-ray, and surface area measurement. These compounds were combined to form cylindrical extrudates of 0.2 cm (diameter) and 1.0 cm (length). The adsorption characteristics of the composites were measured using batch sorption studies as a function of pH, initial concentration, and contact time. The pseudo-second-order model and the Langmuir isotherm model were better suited to the adsorption process. The equilibrium state was achieved around 180 min of adsorption, and a pH of 7 was established as the optimal operating condition. The maximum adsorption values of the dye were obtained with the composites derived from G-Clay, whose average adsorption capacity was 46.36 mg g−1, in contrast with composites derived from R-Clay, whose average adsorption value was 36.24 mg g−1. The results reflect that synthesized composites could be used potentially for the removal of cationic dye from wastewater.

scholarly journals Modification of Fishbone-Based Hydroxyapatite with MnFe2O4 for Efficient Adsorption of Cd(II) and Ni(II) from Aqueous Solution

2021 ◽  
Vol 21 (6) ◽  
pp. 1471
Author(s):  
Poedji Loekitowati Hariani ◽  
Addy Rachmat ◽  
Muhammad Said ◽  
Salni Salni
Keyword(s):  
Heat Treatment ◽  
Aqueous Solution ◽  
Adsorption Process ◽  
Fish Bones ◽  
Adsorption Capacities ◽  
Hydroxyapatite Composite ◽  
Bet Analysis ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Channa Striata

Due to their toxicity, Cd(II) and Ni(II) ions in the environment are severe. The hydroxyapatite composite was improved with magnetic MnFe2O4 to remove Cd(II) and Ni(II) ions from an aqueous solution. Hydroxyapatite was extracted from Snakehead (Channa striata) fish bones via alkaline-heat treatment. The hydroxyapatite/MnFe2O4 composite performance was analyzed through XRD, FTIR, SEM-EDS, BET analysis, and VSM, and the results reveal that the hydroxyapatite/MnFe2O4 composite shows good magnetic properties of 21.95 emu/g. The kinetics evaluation confirmed that the pseudo-second-order kinetics model was more suitable to describe the adsorption of Cd(II) and Ni(II) ions by hydroxyapatite/MnFe2O4 composite from the solution. The Langmuir isotherm model was suitable to describe the adsorption process of the Cd(II) and Ni(II)  ions, where the adsorption capacities for Cd(II) and Ni(II) are 54.3 and 47.4 mg/g, respectively. Desorption of Cd(II) and Ni(II) ions from hydroxyapatite/MnFe2O4 composite using NaCl as the eluent was more effective than EDTA. The findings of this study indicate that hydroxyapatite/MnFe2O4 can reduce Cd(II) and Ni(II) ions in wastewater so that it can recover natural resources.

scholarly journals Application of Biochar to the Remediation of Pb-Contaminated Solutions

2018 ◽  
Author(s):  
Maria Rosaria Boni ◽  
Agostina Chiavola ◽  
Simone Marzeddu
Keyword(s):  
Adsorption Process ◽  
Chemical Characterization ◽  
Complete Removal ◽  
Order Model ◽  
Equilibrium Conditions ◽  
Sem Images ◽  
Adsorption Capacities ◽  
Equilibrium Data ◽  
Pseudo Second Order

The BIOTON® biochar, produced by a wood biomass pyrolysis process, usually applied as a soil amendment, was investigated for a novel application, i.e. the adsorption of lead from contaminated solutions. The experimental activity firstly included the physical-chemical characterization of BIOTON®; SEM images were also obtained to highlight its internal structure. The adsorption process was investigated through batch and column experiments. Adsorption kinetics showed a very rapid achievement of the equilibrium conditions, i.e. at 2h and 4h for 50 mg/L and 100 mg/L initial Pb concentration, respectively. Complete removal also occurred within the same time. The Brunauer–Emmett–Teller model better fitted the equilibrium data for both Pb concentrations, whereas the kinetics were best represented by the pseudo second order model. The column tests showed that the addition of biochar as adsorbent media within the bed significantly extended the time of breakthrough and exhaustion, with respect to the column filled with soil only. The adsorption capacities of BIOTON® versus lead solutions was found to be comparable to that reported for commercial adsorbents. Therefore, BIOTON® can be considered a valid option, with the additional benefit to reduce the environmental impact since allows to recover a residue which alternately would need to be disposed of.

scholarly journals Acid and Ultrasound Assisted Modification of Boron Enrichment Process Waste and Using for Methylene Blue Removal from Aqueous Solutions

2018 ◽  
Vol 20 (2) ◽  
pp. 234-242 ◽  
Keyword(s):  
Methylene Blue ◽  
Dye Removal ◽  
Adsorption Process ◽  
Optimum Conditions ◽  
Process Waste ◽  
Adsorption Capacities ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ultrasound Assisted ◽  
Enrichment Process

In this study, raw boron enrichment waste was treated with hydrochloric acid and ultrasound at 35-kHz frequency for 60 minutes. To optimize the adsorption conditions for removal of methylene blue (MB) from synthetic wastewaters using raw boron enrichment waste (BEW), acid modified boron enrichment waste (HBEW) and ultrasound modified BEW (UBEW) by adsorption process and to compare the adsorption efficiency of chemical and ultrasonic modifications of BEW were aimed. The optimum adsorption conditions were determined economically and eco-friendly aspect and MB removal percents were found as 80%, 80% and 92% at optimum conditions for BEW, HBEW and UBEW, respectively. The maximum regression coefficient values were obtained as 0.911, 0.998 and 0.984 for BEW, HBEW and UBEW, respectively at Langmuir isotherm model. The adsorption rate was fitted well to pseudo-second order kinetics according to a good correlation coefficient. The adsorption of MB onto adsorbents studied is spontaneous in nature and feasible because of negative ∆G values. The results indicated that the boron enrichment process waste could be a suitable adsorbent for removal of MB from aqueous solution. The maximum adsorption capacities were equal to about 107,0 mg/g, 160,7 mg/g and 145,3 mg/g for BEW, HBEW and UBEW adsorbents at 298 K, respectively. The maximum dye removal percent was achieved for UBEW as 92% and ultrasound assisted modification was found more efficient method compared with acidic modification for MB removal.

scholarly journals Adsorption and desorption of Hg(II) from aqueous solution using magnetic Fe3O4@PPy composite microspheres

2021 ◽  
Author(s):  
Xiao-qiang Cao ◽  
Fei Xiao ◽  
Xiao-yu Xie ◽  
Xuan Li ◽  
Guang Li ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Temperature Dependent ◽  
Order Model ◽  
Composite Microspheres ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Recovery Percentage ◽  
Magnetic Fe3o4 ◽  
Satisfactory Recovery

Abstract Functional magnetic Fe3O4@PPy microspheres were prepared and characterized by XRD, FTIR, SEM, TEM, and magnetometer, and the adsorption of Hg(II) onto Fe3O4@PPy was investigated. The results showed that the adsorption of Hg(II) onto Fe3O4@PPy dramatically increases within 5 min and reaches adsorption equilibrium at 200 min. The adsorption of Hg(II) increases with pH increased, and a removal efficiency (RE) of 90.5% was obtained at pH 7.2. The isotherm studies revealed that the adsorption of Hg(II) onto the Fe3O4@PPy fits well with the Langmuir isotherm model, and the calculated qm value of 232.56 mg/g. The adsorption process of Hg(II) onto the Fe3O4@PPy is well-fitted by the pseudo-second-order model with a high correlation coefficient (R2) of 0.999. The thermodynamic coefficients (ΔH°, ΔS°, and ΔG°) were calculated from the temperature-dependent adsorption isotherms and illustrated that the adsorption of Hg(II) on the Fe3O4@PPy was spontaneous and endothermic. Different desorption agents were used to recover Hg(II) adsorbed onto Fe3O4@PPy, and a satisfactory recovery percentage of 93.0% was obtained by using 0.1 M HCl and 0.05 M NaCl.

scholarly journals Application of Wasted Oolong Tea as a Biosorbent for the Adsorption of Methylene Blue

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yunfei Hu ◽  
Yue Zhang ◽  
Yuqun Hu ◽  
Chen-Yao Chu ◽  
Jinke Lin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Adsorption Efficiency ◽  
Order Model ◽  
Oolong Tea ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Second Order Model

Tea powder, a biosorbent prepared from wasted oolong tea, was collected as a prospective adsorbent for the adsorption of methylene blue (MB) from aqueous solution. The effect of factors on adsorption efficiency, isotherms, kinetics, and potential mechanism was carried out. Adsorption capacity of MB onto wasted tea powder increased with the MB concentration and contact time, whereas the increase in pH value and ion strength appeared to have a negative effect for the adsorption process. The adsorption efficiency increased rapidly and reached a stable state within 120 min. The optimal tea powder loading weight is suggested to be at 0.1 to 0.2 g, and the highest efficiency of 94.8% is achieved at 333 K. There were no significant changes in adsorption efficiency when the effect of temperature is considered. The Langmuir isotherm model was found to be the best isotherm models to elucidate the adsorption mechanism in this study. The maximum adsorption capacities calculated at different temperatures by the Langmuir model ranging from 312.5 to 333.3 mg·g−1 were much close to the experimental results. From the kinetic analysis, the pseudo--second-order model was found to be the best model to describe the adsorption behavior. The calculated adsorption capacities at different initial MB concentrations by the pseudo-second-order model ranging from 92.34 to 400 mg·g−1 were well close to the experimental data. The fitting results obtained from the intraparticle diffusion model suggested that the intraparticle diffusion was not the only rate-controlling step and some other mechanisms along with the intraparticle diffusion were probably involved. The intraparticle diffusion of MB molecules into pore structures of wasted tea powder is the rate-limiting step for the adsorption process in this study. The repetitive cycle experiments indicated that the wasted oolong tea powder was efficiently regenerated using NaOH and thus be used for many times.

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