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

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.

2021 ◽  
Vol 10 (4) ◽  
pp. 48-55
Author(s):  
Tran To Uyen ◽  
Trinh Thi Tu Anh ◽  
Tamikazu Kume ◽  
Cao Dong Vu ◽  
Nguyen Minh Hiep ◽  
...  

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


2019 ◽  
Vol 80 (7) ◽  
pp. 1357-1366
Author(s):  
Jianming Liu ◽  
Runying Bai ◽  
Junfeng Hao ◽  
Bowen Song ◽  
Yu Zhang ◽  
...  

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.


Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3127
Author(s):  
Risi Wang ◽  
Ya Li ◽  
Xixiang Shuai ◽  
Jun Chen ◽  
Ruihong Liang ◽  
...  

Traditional aerogels lack specific functional groups for the adsorption of Pb2+, which results in a low adsorption capacity and limits the application scope. Novel porous pectin-based aerogels (PPEAs) were prepared by incorporating polyethylenimine (PEI) using ethylene glycol diglycidyl ether (EGDE) as a cross-linker for the removal of Pb2+ from water. The cross-linking mechanism, morphology, mechanical strength, thermal stability, adsorption properties, and mechanism of the aerogels were investigated. The aerogels possessed several desirable features, such as a large maximum Pb2+ adsorption capacity (373.7 mg/g, tested at pH 5.0), ultralight (as low as 63.4 mg/cm3), high mechanical strength (stress above 0.24 MPa at 50% strain), and easy recyclability. Meanwhile, the equilibrium adsorption data was well described by the Langmuir–Freundlich (Sips) model and the kinetic adsorption process was well fitted using the pseudo-second-order model. The donor groups, such as -NH2, and oxygen-containing functional groups were responsible for the Pb2+ adsorption, which was confirmed by the FTIR and XPS analysis. The excellent characteristics mean that PPEAs are highly effective adsorbents in the remediation of lead-containing wastewater.


2019 ◽  
Author(s):  
Chem Int

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.


2017 ◽  
Vol 75 (7) ◽  
pp. 1651-1658 ◽  
Author(s):  
Hongyu Jia ◽  
Ningning Liu

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.


2012 ◽  
Vol 209-211 ◽  
pp. 2005-2008 ◽  
Author(s):  
Fang Juan Zhang ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang

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.


2011 ◽  
Vol 233-235 ◽  
pp. 1972-1980 ◽  
Author(s):  
Yu Bin Tang ◽  
Fang Yu ◽  
Fang Yan Chen ◽  
Cheng Chen

Rectorite (REC), humic acid (HA) and polyvinyl alcohol (PVA) were used to prepare microspheres. Batch adsorption experiments of Pb2+ion on to the microspheres were performed. The results obtained indicate that adsorption time, the microspheres dosage and temperature were the main factors influencing the adsorptive capacities. The adsorption data for Pb2+ion were well described by the Freundlich, Langmuir and Temkin models. The kinetic experimental data properly correlated with the pseudo-first-order model, pseudo-second-order model and Elovich equation. The adsorption process is spontaneous, endothermic and out-of-order. The whole adsorption process is mainly controlled by entropies. The adsorption can be classified as chemical adsorption. The mechanisms for the adsorption of Pb2+ion on to the microspheres involved ion-exchange adsorption of Pb2+or the formation of complex compound. Under the experimental conditions employed, the removal of Pb2+ion attained value of 96.05%.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 898
Author(s):  
Ximena Jaramillo-Fierro ◽  
Silvia González ◽  
Fernando Montesdeoca-Mendoza ◽  
Francesc Medina

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.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1519
Author(s):  
Zhuo Wang ◽  
Ha Neul Park ◽  
Sung Wook Won

In this study, the optimal conditions for the fabrication of polyethylenimine/polyvinyl chloride cross-linked fiber (PEI/PVC-CF) were determined by comparing the adsorption capacity of synthesized PEI/PVC-CFs for Reactive Yellow 2 (RY2). The PEI/PVC-CF prepared through the optimal conditions was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analyses. Several batch adsorption and desorption experiments were carried out to evaluate the sorption performance and reusability of PEI/PVC-CF for RY2. As a result, the adsorption of RY2 by PEI/PVC-CF was most effective at pH 2.0. A pseudo-second-order model fit better with the kinetics adsorption data. The adsorption isotherm process was described well by the Langmuir model, and the maximum dye uptake was predicted to be 820.6 mg/g at pH 2.0 and 25 °C. Thermodynamic analysis showed that the adsorption process was spontaneous and endothermic. In addition, 1.0 M NaHCO3 was an efficient eluent for the regeneration of RY2-loaded PEI/PVC-CF. Finally, the repeated adsorption–desorption experiments showed that the PEI/PVC-CF remained at high adsorption and desorption efficiencies for RY2, even in 17 cycles.


2021 ◽  
Vol 21 (6) ◽  
pp. 1471
Author(s):  
Poedji Loekitowati Hariani ◽  
Addy Rachmat ◽  
Muhammad Said ◽  
Salni Salni

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.


Sign in / Sign up

Export Citation Format

Share Document