scholarly journals Removal of Cr(VI) from Aqueous Environments Using Micelle-Clay Adsorption

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohannad Qurie ◽  
Mustafa Khamis ◽  
Adnan Manassra ◽  
Ibrahim Ayyad ◽  
Shlomo Nir ◽  
...  

Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.

2019 ◽  
Vol 7 (1) ◽  
pp. 029
Author(s):  
Nelly Wahyuni ◽  
Imelda H. Silalahi ◽  
Dina Angelina

Abstrak Fenol merupakan polutan yang sangat berbahaya di lingkungan karena bersifat racun dan sulit terdegradasi oleh organisme pengurai. Lempung alam yang berasal dari Kecamatan Capkala, Kabupaten Bengkayang  akan dikaji penggunaannya sebagai adsorben fenol. Adsorpsi dilakukan dengan metoda batch pada variasi waktu kontal dan konsentrasi awal fenol. Data kesetimbangan adsorpsi diuji dengan isoterm Langmuir dan Freundlich. Hasil penelitian menunjukkan waktu kontak optimum adsorpsi adalah 4 jam. Proses adsorpsi fenol  oleh lempung alam  mengikuti model isoterm adsorpsi Langmuir dengan kapasitas adsorpsi sebesar 0,65mg/g. Kata Kunci: fenol, Freundlich, isoterm adsorpsi, Langmuir, lempung alamAbstract Phenol is a pollutant that is very dangerous in the environment because it is toxic and difficult to degrade by decomposing organisms. Natural clay from Capkala District, Bengkayang Regency will be studied as phenol adsorbent. Batch experiments were carried out by varying the parameters like contact time of adsorption and initial phenol concentration. The equilibrium data were tested with Langmuir and Freundlich isotherm. The results showed that the optimum contact time for adsorption was 4 hours. The process of adsorption of phenol by natural clay follows the Langmuir adsorption isotherm model with an adsorption capacity of 0.65mg/g.  Keywords: adsorption isotherm, Freundlich, natural clay, phenol, Langmuir.


Author(s):  
Somayeh Rahdar ◽  
Shahin Ahmadi

Background and purpose: The aim of this study was to evaluate the efficiency of zinc oxidenanoparticles (ZnO NPs) in combination with US-H2O2 advanced oxidation processes (AOPs) for the removal of antibiotic amoxicillin (AMO) from aquatic environment.Materials and Methods: This experimental study was conducted in a batch reactor system. The effect of the parameters, such as pH (3-8), the dose of nanoparticles (0.01-0.08 g/L), reaction time (10-100 min), the initial concentration of the AMO (150-250 mg/L) and H2O2 (0.1 – 5Mol/L) on the removal efficiency were studied in ultrasonic reactor. The residual AMO concentrations were measured at 190 nm using a UV/Vis spectrophotometer.Results: The results showed that the US-H2O2 advanced oxidation processes using ZnO NPs can effectively lead to the removal of AMO from the wastewater. The optimal conditions for this process were pH 3, 0.1 M of H2O2 and the dose ZnO NPs 0.05 g/L and time of 60 minutes. In the current study, it was found that the removal efficiency dropped with the increasing concentrations of AMO. Under optimal conditions with 150 mg/L of AMO and contact time of 60 min, the efficiency removal was also equal to 92.47%.Conclusion: The results of this study showed that AOP was a very effective method that can be used for the removal of AMO antibiotic from aqueous solutions.


2019 ◽  
Vol 9 (4) ◽  
pp. 697
Author(s):  
Vladimir Petrov ◽  
Zhong Chen ◽  
Anna Romanchuk ◽  
Valeria Demina ◽  
Yuxin Tang ◽  
...  

Hydrogen titanates (H-titanates) of different nanostructures (nanotubes, nanowires, nanosheets) have been synthesized by hydrothermal methods. The europium (III) sorption from aqueous solutions onto nano-sized H-titanates was studied as a function of contact time, pH values, and initial Eu (III) concentration in batch experiments. Reversibility of adsorption of europium has been investigated as well. Nano-sized H-titanates can be used for tri-valent f-elements removal in polluted water treatment due to fast and efficient sorption of Eu (III).


2013 ◽  
Vol 726-731 ◽  
pp. 2931-2935
Author(s):  
Qi Bin Liang ◽  
Yun Gen Liu ◽  
Kun Tian

The study aimed at phosphorus and nitrogen removal by honeycomb cinder modified with Zinc chloride (ZnCl2). By bench-scale batch experiments, honeycomb cinders with different modification time and ZnCl2 dosage were modified and its adsorption capacities were evaluated by methylence blue as the adsorbate. Under the optimal modification conditions, large amount modified honeycomb cinders were prepared to remove the phosphorus and nitrogen from domestic sewage, which different operating conditions of honeycomb cinders dosage, and contact time were considered. The results show that removal efficiencies of total phosphate (TP), orthophosphate (PO43-P), total nitrogen (TN) and ammonia nitrogen (NH4+-N) could reach 89.9%, 96.7%, 18.9% and 23.3% under the optimal conditions, respectively. Modified honeycomb cinders might be an effective and low cost adsorbent for phosphorus removal.


1990 ◽  
Vol 70 (3) ◽  
pp. 305-311 ◽  
Author(s):  
BAOHUA GU ◽  
L. E. LOWE

The adsorption of B, in the form of boric acid, was studied on three precipitated humic acids (HA), representing three distinct soil types. B adsorption by HA was strongly pH-dependent, being low and relatively constant in the pH range 3.0–6.5, increasing markedly up to a peak at near pH 9.5, and then decreasing at still higher pH values. Adsorption isotherms for pH values near 6.7 and 8.8 conformed well to the Langmuir equation. The adsorption maxima (b values), as calculated with the Langmuir equation, ranged from 73 to 207 mmol kg−1 HA at a pH near 8.8, and from 10 to 42 mmol kg−1 at a pH near 6.7. The considerable variation in B adsorption by these HA samples was attributed to "Fe + Al" contents present as contaminants in the HA. The role of HA in B adsorption is expected to be minor in most acid and near neutral soils, but may be of greater significance in soils of high pH and above average organic matter content. Key words: Boron adsorption, boric acid, humic acid, Langmuir adsorption isotherm.


2012 ◽  
Vol 724 ◽  
pp. 61-64
Author(s):  
Ying Li ◽  
Xiao Yan Lin ◽  
Zhe Chen ◽  
Xue Guang Luo ◽  
Wei Li Zuo

A composite membrane of thermoplastic carboxymethyl cellulose (TCMC) /PLA was prepared by electrospinning process, and crossliked by epichlorohydrin solution at different temperature. The cross-linking temperature was optimized by characterizing the morphology and tensile strength of the film. The optimal cross-linking temperature was 50°C. A composite membrane was used to remove Cu2+ from aqueous solutions, and the effects of initial concentration of Cu2+ and contact time on the removal efficiency of Cu2+ were investigated. The removal efficiency of Cu2+ was 13.78%, at the initial concentration of 40 mg·L-1 and contact time of 30s.


2020 ◽  
Vol 81 (1) ◽  
pp. 10-20 ◽  
Author(s):  
T. Reinhardt ◽  
M. Gómez Elordi ◽  
R. Minke ◽  
H. Schönberger ◽  
E. Rott

Abstract Phosphonates are widely used in various industries. It is desirable to remove them before discharging phosphonate-containing wastewater. This study describes a large number of batch experiments with adsorbents that are likely suitable for the removal of phosphonates. For this, adsorption isotherms for four different granular ferric hydroxide (GFH) adsorbents were determined at different pH values in order to identify the best performing material. Additionally, the influence of temperature was studied for this GFH. A maximum loading for nitrilotrimethylphosphonic acid (NTMP) was found to be ∼12 mg P/g with an initial concentration of 1 mg/L NTMP-P and a contact time of 7 days at room temperature. Then, the adsorption of six different phosphonates was investigated as a function of pH. It was shown that GFH could be used to remove all investigated phosphonates from water and, with an increasing pH, the adsorption capacity decreased for all six phosphonates. Finally, five adsorption–desorption cycles were carried out to check the suitability of the material for multiple re-use. Even after five cycles, the adsorption process still performed well.


2019 ◽  
Vol 6 (2) ◽  
pp. 66-74 ◽  
Author(s):  
Raziyeh Hosseini ◽  
Mohammad Hossein Sayadi ◽  
Hossein Shekari

The research was conducted with an aim to assess the efficiency of copper oxide nanoparticles as an adsorbent to remove Ni and Cr. The effect of pH, adsorbent dosage, contact time, initial concentration of metals (Ni and Cr) on the adsorption rate was evaluated and removal of these elements from aqueous solutions was measured using Atomic Absorption Spectrum System (Conter AA700). Moreover, the kinetic and isotherm besides thermodynamic adsorption models were assessed. The highest Ni and Cr removal rate occurred at an optimal pH of 7, and an initial concentration of 30 mg/L, a time period of 30 minutes, and 1 g/L of copper oxide nanoparticles. In fact, with the increase of adsorbent dosage and contact time, the removal efficiency increased and with initial concentration increase of Ni and Cr ions, the removal efficiency reduced. The correlation coefficient of isotherm models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson, and Koble-Corrigan showed that Ni and Cr adsorption via copper oxide nanoparticles better follows the Langmuir model in relation to other models. The results showed that kinetic adsorption of Ni and Cr via copper oxide nanoparticles follows the second order pseudo model with correlation coefficients above 0.99. In addition, the achieved thermodynamic constants revealed that the adsorption process of metals (i.e., Ni and Cr) via copper oxide nanoparticles was endothermic and spontaneous and the reaction enthalpy values for these metals were 17.727 and 11.862 kJ/mol, respectively. In conclusion, copper oxide nanoparticles can be used as effective and environmentally compatible adsorbents to remove Ni and Cr ions from the aqueous solutions


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 607 ◽  
Author(s):  
Mingliang Ge ◽  
Zhuangzhuang Xi ◽  
Caiping Zhu ◽  
Guodong Liang ◽  
Guoqing Hu ◽  
...  

The magadiite–magnetite (MAG–Fe3O4) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe3O4 and the high adsorption capacity of pure magadiite (MAG). MAG–Fe3O4 was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results showed that Fe3O4 nanoparticles were deposited on the interlayer and surface of magadiite. MAG–Fe3O4 was treated as an adsorbent for methylene blue (MB) removal from aqueous solutions. The adsorption properties of MAG–Fe3O4 were investigated on methylene blue; however, the results showed that the adsorption performance of MAG–Fe3O4 improved remarkably compared with MA and Fe3O4. The adsorption capacity of MAG–Fe3O4 and the removal ratio of methylene blue were 93.7 mg/g and 96.2%, respectively (at 25 °C for 60 min, pH = 7, methylene blue solution of 100 mg/L, and the adsorbent dosage 1 g/L). In this research, the adsorption experimental data were fitted and well described using a pseudo-second-order kinetic model and a Langmuir adsorption isotherm model. The research results further showed that the adsorption performance of MAG–Fe3O4 was better than that of MAG and Fe3O4. Moreover, the adsorption behavior of MB on MAG–Fe3O4 was investigated to fit well in the pseudo-second-order kinetic model with the adsorption kinetics. The authors also concluded that the isothermal adsorption was followed by the Langmuir adsorption isotherm model; however, it was found that the adsorption of the MAG–Fe3O4 nanocomposite was a monolayer adsorption.


2014 ◽  
Vol 692 ◽  
pp. 149-155 ◽  
Author(s):  
Jun Ren ◽  
Dan Xu ◽  
Ling Tao ◽  
Zhao Wen Fu

The adsorption behavior of Zn (II) by attapulgite were studied in the paper, The effects of adsorbent dose. Contact time, ionic strength and temperature on the adsorption were investigated. The maximum adsorption capacity is 4.129 mg.g-1 at 333 K. The kinetic study indicated that the adsorption was a pseudo-second-order process. The adsorption was well fitted by the Langmuir adsorption isotherm model. The results indicated that the sorption of Zn (II) by attapulgite was a spontaneous process, and the sorption was endothermic.


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