scholarly journals Al-Waste-Based Zeolite Adsorbent Used for the Removal of Ammonium from Aqueous Solutions

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Ruth Sánchez-Hernández ◽  
Isabel Padilla ◽  
Sol López-Andrés ◽  
Aurora López-Delgado

This work evaluates the use of a synthetic NaP1 zeolite obtained from a hazardous Al-containing waste for the removal of ammonium (NH4+) from aqueous solutions by batch experiments. Experimental parameters, such as pH (6–8), contact time (1–360 min), adsorbent dose (1–15 g/L), and initial NH4+ concentration (10–1500 mg/L), were evaluated. Adsorption kinetic models and equilibrium isotherms were determined by using nonlinear regression. The kinetic was studied by applying both the pseudo-first-order and pseudo-second-order models. The equilibrium isotherms were analyzed according to two-parameter equations (Freundlich, Langmuir, and Temkin) and three-parameter equations (Redlich–Peterson, Sips, and Toth). The results showed that the NH4+ uptake on NaP1 was fast (15 min) leading to a high experimental sorption capacity (37.9 mg/g). The NH4+ removal on NaP1 was a favorable process that followed the pseudo-first-order kinetic model. The NH4+ adsorption was better described by the Sips (54.2 mg/g) and Toth (58.5 mg/g) models. NaP1 zeolite from Al-waste showed good NH4+ sorption properties, becoming a potential adsorbent to be used in the treatment of contaminated aqueous effluents. Thus, a synergic effect on the environmental protection can be achieved: the end of waste condition of a hazardous waste and the water decontamination.

2013 ◽  
Vol 741 ◽  
pp. 55-58
Author(s):  
Wen Lian Luo

The removal of Cu2+ ions from aqueous solution was studied using pickled diatomite samples. The linear Langmuir and Freundlich adsorption equations were applied to describe the equilibrium isotherms. The pseudo-first-order and pseudo-second-order models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model.


2018 ◽  
Vol 66 (2) ◽  
pp. 121-127
Author(s):  
AZM Mainul Islam Mazumder ◽  
Chowdhury Raihan Bikash ◽  
Md Ataur Rahman ◽  
Md Mufazzal Hossain

Adsorptive removal of remazol red R (RRR) and remazol black B (RBB) from aqueous solution has been investigated by using ZnO as an adsorbent. Time for adsorption equilibrium, kinetics of adsorption at different initial concentrations of dyes and adsorption isotherms at different temperatures have been studied. Adsorption capacity increased with increasing initial dye concentration. The pseudo first-order and pseudo second-order kinetics were used to describe kinetic data and the rate constants were evaluated. Experimental data fits better in the pseudo second-order kinetic model than in the pseudo first-order kinetic model for both the dyes. Langmuir and Freundlich isotherm models were applied to describe the adsorption of RRR and RBB onto ZnO powders. Langmuir isotherm model provided a better correlation for the experimental data in comparison to the Freundlich isotherm model. Adsorption of both RRR and RBB on ZnO are physical in nature and increases with decreasing temperature. The equilibrium adsorption capacity decreases from 3.43 mg/g at 200C to 2.36 mg/g at 400C for RRR whereas that in the case of RBB changes from 0.77 mg/g at 300C to 0.75 mg/g at 400C. Adsorption of RRR on ZnO was found to be three times higher than the adsorption of RBB at a particular temperature. A model for adsorption of both the dyes has been proposed. Dhaka Univ. J. Sci. 66(2): 121-127, 2018 (July)


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaoyu Li ◽  
Fengbo Li ◽  
Lejin Fang

The adsorption of naphthalene on graphene oxide (GO) nanosheets in presence of Paecilomyces cateniannulatus (P. cateniannulatus) was conducted by the batch techniques. The morphology and nanostructure of GO were characterized by SEM, TEM, FTIR, XPS, and Raman. The adsorption kinetics indicated that the adsorption of naphthalene on GO and GO + P. catenlannulatus can be satisfactorily fitted pseudo-first-order and pseudo-second-order kinetic model, respectively. P. catenlannulatus inhibited the adsorption of naphthalene on GO at pH<4.0, whereas the increased adsorption was observed at pH>4.0. The adsorption of naphthalene on GO and GO + P. catenlannulatus can be better fitted by Langmuir and Freundlich model, respectively. The change in the conformation of GO was responsible to the increased adsorption of naphthalene by SEM and TEM images. According to FTIR analysis, naphthalene was absorbed by the oxygen-containing functional groups of GO, especially for –COOH. The finding in the study provides the implication for the preconcentration and removal of polycyclic aromatic hydrocarbons from environment cleanup applications.


2013 ◽  
Vol 842 ◽  
pp. 175-179
Author(s):  
Liang Jia ◽  
Jing Song Wang ◽  
Qing Wei Guo ◽  
Xiao Liang Zou ◽  
Lei Xie

This paper aims to investigate the adsorption of Cr (VI) by cross-linked magnetic hydroxamated chitosan (MHCTS). The adsorption experiments were carried out in batch systems. To determine the optimum condition of the adsorption, factors such as pH, reaction time, initial Cr (VI) concentration and adsorbent dosage were considered. The experimental results showed that MHCTS can adsorb Cr (VI) with high efficiency. Optimum adsorption was observed at pH 4.0, and the highest adsorption removal reached 99.2%. The equilibrium was established within 90 min. The process could be described by pseudo-first-order and pseudo-second-order kinetic model.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Javier Paul Montalvo Andia ◽  
Lidia Yokoyama ◽  
Luiz Alberto Cesar Teixeira

In the present work, the equilibrium, thermodynamics, and kinetics of boron removal from aqueous solutions by the adsorption on commercial magnesium oxide powder were studied in a batch reactor. The adsorption efficiency of boron removal increases with temperature from 25°C to 50°C. The experimental results were fitted to the Langmuir, Freundlich, and Dubinin–Radushkevich (DR) adsorption isotherm models. The Freundlich model provided the best fitting, and the maximum monolayer adsorption capacity of MgO was 36.11 mg·g−1. In addition, experimental kinetic data interpretations were attempted for the pseudo-first-order kinetic model and pseudo-second-order kinetic model. The results show that the pseudo-second-order kinetic model provides the best fit. Such result suggests that the adsorption process seems to occur in two stages due to the two straight slopes obtained through the application of the pseudo-first-order kinetic model, which is confirmed by the adjustment of the results to the pseudo-second-order model. The calculated activation energy (Ea) was 45.5 kJ·mol−1, and the values calculated for ∆G°, ∆H°, and ∆S° were −4.16 kJ·mol−1, 21.7 kJ·mol−1, and 87.3 kJ·mol−1, respectively. These values confirm the spontaneous and endothermic nature of the adsorption process and indicated that the disorder increased at the solid-liquid interface. The results indicate that the controlling step of boron adsorption process on MgO is of a physical nature.


2018 ◽  
Vol 38 ◽  
pp. 02014
Author(s):  
Yu Zhang ◽  
Jian Gu ◽  
Mengqi Zhang

The wool-ball-like TiO2 microspheres on carbon fabric (TiO2-CF) and FTO substrates (TiO2-FTO) have been synthesized by a facile hydrothermal method in alkali environment, using commercial TiO2 (P25) as precursors. The XRD results indicate that the as-prepared TiO2 have good crystallinity. And the SEM images show that the wool-ball-like TiO2 microspheres with a diameter of 2-3 μm are composed of TiO2 nanowires, which have a diameter of ~50 nm. The photocatalytic behavior of the wool-ball-like TiO2 microspheres, TiO2-CF and TiO2-FTO under ultraviolet light was investigated by a pseudo first-order kinetic model, using methyl orange (MO) as pollutant. The wool-ball-like TiO2 microspheres obtained a degradation rate constant (Kap) of 6.91×10-3 min-1 . The Kap values of TiO2-FTO and TiO2-CF reach 13.97×10-3 min-1 and 11.80×10-3 min-1, which are 2.0 and 1.7 times higher than that of pristine wool-ball-like TiO2 microspheres due to the “sum effect” between TiO2 and substrates. This study offers a facile hydrothermal method to prepare wool-ball-like TiO2 microspheres on CF and FTO substrates, which will improve the recyclability of phtocatalysts and can be extended to other fields.


Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1899 ◽  
Author(s):  
Jun ◽  
Kim ◽  
Han ◽  
Yoon ◽  
Kim ◽  
...  

For this study, we applied activated biochar (AB) and its composition with magnetite (AB-Fe3O4) as adsorbents for the removal of polychlorophenols in model wastewater. We comprehensively characterized these adsorbents and performed adsorption tests under several experimental parameters. Using FTIR, we confirmed successful synthesis of AB-Fe3O4 composite through cetrimonium bromide surfactant. We conducted adsorption tests using AB and AB-Fe3O4 to treat model wastewater containing polychlorophenols, such as 2,3,4,6-Tetrachlorophenol (TeCP), 2,4,6-Trichlorophenol (TCP), and 2,4-Dichlorophenol (DCP). Results of the isotherm and the kinetic experiments were well adapted to Freundlich’s isotherm model and the pseudo-second-order kinetic model, respectively. Main adsorption mechanisms in this study were attributed to non-covalent, π-electron acceptor–donor interactions and hydrophobic interactions judging from the number of chloride elements in each chlorophenol and its hydrophobic characteristics. We also considered the electrostatic repulsion effect between TeCP and AB, because adsorption performance of TeCP at basic condition was slightly worse than at weak acidic condition. Lastly, AB-Fe3O4 showed high adsorption selectivity of TeCP compared to other persistent organic pollutants (i.e., bisphenol A and sulfamethoxazole) due to hydrophobic interactions. We concluded that AB-Fe3O4 may be used as novel adsorbent for wastewater treatment including toxic and hydrophobic organic pollutants (e.g., TeCP).


2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order


2015 ◽  
Vol 71 (11) ◽  
pp. 1611-1619 ◽  
Author(s):  
Jun Liu ◽  
Hongyan Du ◽  
Shaowei Yuan ◽  
Wanxia He ◽  
Pengju Yan ◽  
...  

Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T = 293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (–CO−) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions.


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