Adsorption Removal of Fluoride from Aqueous Solution by Hydroxy-Iron Pillared Montmorillonite

2013 ◽  
Vol 781-784 ◽  
pp. 2273-2276
Author(s):  
Shi Yong Wei ◽  
Xu Hong Deng
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Interlayer Spacing ◽  
Multilayer Adsorption ◽  
Pillared Montmorillonite ◽  
Fluoride Adsorption ◽  
Adsorption Behaviors ◽  
Adsorption Removal ◽  
Adsorption Data ◽  
Adsorption Processes

Hydroxy-iron pillared montmorillonite (Fe-Mont) was prepared and characterized, and the fluoride adsorption capacity of Fe-Mont was investigated. Compared to pure montmorillonite (Mont), the interlayer spacing, specific surface area (SSA), surface fractal dimension and isoelectric point (IEP) of Fe-Mont increased. At pH 4.5, the Langmuir adsorption capacity (qmax) for fluoride of Mont and Fe-Mont was 4.23 and 6.92 mg/g, respectively. The adsorption data for fluoride by Fe-Mont could be fitted by Langmuir model (R2 =0.986) and also by Freundlich isotherm (R2 =0.948), and indicating that the monolayer and multilayer adsorption behaviors are simultaneously involved in the fluoride adsorption processes of Fe-Mont.

Adsorption of Methylene Blue from Aqueous Solution Using Honeycomb-Cinder

2012 ◽  
Vol 550-553 ◽  
pp. 2259-2262
Author(s):  
Song Bo Cui ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Dye Wastewater ◽  
Batch System ◽  
Adsorption Data ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Mb Adsorption

The adsorption behavior of methylene blue (MB) dye from aqueous solutions onto honeycomb-cinder (HC) and its acid-activated product was investigated in a batch system. The results showed the adsorption capacity was decreased for raw HC samples with the increase of pH value, while it was increased for activated samples. The adsorption data were fit with Langmuir isotherm model for MB adsorption by all samples. The MB adsorption capacity on samples was increased from 2.62 mg/g to 7.81 mg/g and 7.00 mg/g after acid-activated by HCl and H2SO4, respectively. The adsorption processes of MB followed pseudo-second-order kinetics with a coefficient of correlation≥0.99. This study demonstrated that acid-activated HC has superior adsorbing ability for MB than raw HC and can be used as alternative adsorbents in dye wastewater treatment.

scholarly journals Adsorption Behaviors of Oxytetracycline onto Sediment in the Weihe River, Shaanxi, China

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dong-Hui Cheng ◽  
Sheng-Ke Yang ◽  
Yue Zhao ◽  
Jing Chen
Keyword(s):  
Freundlich Isotherm ◽  
Entropy Change ◽  
Impact Factors ◽  
Isotherm Models ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Adsorption Data ◽  
Negative Effect ◽  
Weihe River ◽  
The Impact

Adsorption behaviors of oxytetracycline onto sediment in the Weihe River were described. The impact factors in the processes of adsorption, such as contact time, solution pH, temperature, and ionic strength, were determined by experiments. The experimental results were analyzed by kinetic and isotherm models. The adsorption kinetics was found to follow a pseudo-first-order model. The equilibrium adsorption data fitted well with the Langmuir and Freundlich isotherm models. However, the Langmuir isotherm was more suitable to describe the adsorption. Thermodynamics parameters such as Gibbs-free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated. Results showed that the adsorption was feasible, spontaneous, entropy increasing, and endothermic in nature, which reached equilibrium in about 24 hours. The adsorption capacity did not cause obvious change at solution pH 4.0–7.0, and both decreased in solution pH 7.0–10.0 and 4.0–2.0. The presence of electrolytes such as NaCl in aqueous solution had a significant negative effect on the adsorption. The mechanisms controlling the adsorption were supposed to be chemisorption.

The Removal and Inhibitory Effect of CNTs on Model Viruses

2013 ◽  
Vol 743-744 ◽  
pp. 402-408 ◽  
Author(s):  
Shi Yuan Liu ◽  
Xiang Zheng ◽  
Ye Yang ◽  
Jia Liu ◽  
Jie Li
Keyword(s):  
Freundlich Isotherm ◽  
Inhibitory Effect ◽  
Multilayer Adsorption ◽  
Adsorption Effect ◽  
Ms2 Bacteriophage ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Static And Dynamic Tests ◽  
The Impact ◽  
Removal System

Nanomaterial is becoming an important adsorption or disinfection material for removing virus from drinking water. In this study, static and dynamic tests were used to examine adsorption and inhibition characteristics of carbon nanotubes (CNTs) on two model viruses -- f2 and MS2 bacteriophage. Controlling variate method was used to systematically investigate the adsorption kinetics and adsorption isotherms of CNTs on two model viruses; as well as to find the impact of different CNTs dosages on adsorption effect; and then to study the inhibitory effect of CNTs.The results showed that: (1) The adsorption process of f2 and MS2 bacteriophage on CNTs corresponded well with the pseudo-second-order kinetics equation. Time to reach a saturation equilibrium adsorption is about 30min. (2) Both the Langmuir and Freundlich isotherm adequately described two adsorption processes which indicated that the removal mechanism of virus was a mix of monolayer and multilayer adsorption. (3)The dosage of a single removal system should not be too high in practical application. (4) The inhibition of CNTs on model viruses exhibited.

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

ADSORPTION OF ACID ORANGE 7 BY CETYLPYRIDINIUM BROMIDE MODIFIED SUGARCANE BAGASSE

2016 ◽  
Vol 78 (1-2) ◽  
Author(s):  
Nik Ahmad Nizam Nik Malek ◽  
Nurain Mat Sihat ◽  
Mahmud A. S. Khalifa ◽  
Auni Afiqah Kamaru ◽  
Nor Suriani Sani
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Sugarcane Bagasse ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Acid Orange 7 ◽  
Cetylpyridinium Bromide ◽  
Batch Mode ◽  
Acid Orange ◽  
Adsorption Data

In the present study, the adsorption of acid orange 7 (AO7) dye from aqueous solution by sugarcane bagasse (SB) and cetylpyridinium bromide (CPBr) modified sugarcane bagasse (SBC) was examined. SBC was prepared by reacting SB with different concentrations (0.1, 1.0 and 4.0 mM) of cationic surfactant, CPBr. The SB and SBC were characterized using Fourier transform infrared (FTIR) spectroscopy. The adsorption experiments were carried out in a batch mode. The effect of initial AO7 concentrations (5-1000 mg/L), initial CPBr concentrations and pH of AO7 solution (2-9) on the adsorption capacity of SB and SBC were investigated. The experimental adsorption data were analyzed using Langmuir and Freundlich isotherm models. The adsorption of AO7 onto SB and SBC followed Freundlich and Langmuir isotherm models, respectively. The maximum uptake of AO7 was obtained by SBC4.0 (SB treated with 4.0 mMCPBr) with the adsorption capacity of 144.928 mg/g. The highest AO7 removal was found to be at pH 2 and 7 for SB and SBC, respectively. As a conclusion, sugarcane bagasse modified with CPBr can become an alternative adsorbent for the removal of anionic compounds in aqueous solution.

Coating Iron Oxides on Kaolinite for the Adsorption of Fluoride

2012 ◽  
Vol 479-481 ◽  
pp. 250-254
Author(s):  
Wen Jun Xiang
Keyword(s):  
Iron Oxides ◽  
Freundlich Isotherm ◽  
Zero Point ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluoride Adsorption ◽  
Adsorption Data ◽  
Co Precipitation

Iron oxides-coated kaolinite (Fe-Kaolinite) was prepared by co-precipitation and indentified using X-ray diffraction (XRD). Moreover, the surface properties and fluoride adsorption characteristics of Fe-Kaolinite were investigated and compared with those of kaolinite. Compared to kaolinite, the BET surface area and surface fractal dimension of Fe-Kaolinite increased significantly. The pH at zero point of charge (pHZPC) of kaolinite and Fe-Kaolinite was 3.16 and 6.24, respectively. In the suspensions of pH 6.0, the fitted maximum adsorption capacity (qmax) for fluoride of kaolinite and Fe-Kaolinite was 1.32 and 5.86 mg/g, respectively. The adsorption data for fluoride by Fe-Kaolinite could be fitted using Freundlich isotherm (R2 =0.987), and Langmuir isotherm was very suitable for describing the fluoride adsorption of kaolinite (R2 =0.991).

Roles of the Porosity and Surface Oxygen Groups on the Adsorption of Methane on Coals

2013 ◽  
Vol 781-784 ◽  
pp. 2415-2419 ◽  
Author(s):  
Shi Xiong Hao ◽  
Zu Xiao Yu ◽  
Xing Yong Liu
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Methane Adsorption ◽  
Coal Surface ◽  
Surface Oxygen Groups ◽  
Adsorption Behaviors ◽  
Two Samples ◽  
Adsorption Data ◽  
Oxygen Groups ◽  
Adsorption Of Methane

One bituminous coal was modified with H2O2, (NH4)2S2O8 and HNO3 respectively, to prepare coal samples with different surface properties. The oxygen groups on coal surface were characterized by X-ray photoelectron spectroscopy (XPS). The textures of the coal samples were investigated by N2 adsorption at 77 K. The methane adsorption behaviors of the coal samples were measured at 303 K in pressure range of 0-5.3 MPa by a volumetric method. The methane adsorption data were fitted to the Langmuir model. It was observed that there was, in general, a positive correlation between the methane adsorption capacity and the SBET of coals while a negative correlation between methane saturated adsorption capacity and the Ototal/Ctotal. The methane adsorption capacity was determined by the coal surface chemistry when the microporosity parameters of two samples were similar. Coal with a higher amount of oxygen surface groups, and consequently with a less hydrophobic character, had lower methane adsorption capacity.

scholarly journals Bioadsorption of lead(II) over the pulp of Acrocomia aculeata

2021 ◽  
Vol 46 (4) ◽  
pp. 38-46
Author(s):  
Alexandra Novak ◽  
F�tima Yubero ◽  
Diana Diez-P�rez-N��ez ◽  
Fernando Luis Fertonani ◽  
Brenda Gisselle Da Silva Britez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Column Experiments ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Adsorption Data ◽  
Acrocomia Aculeata ◽  
Scanning Electron

The adsorption of lead in aqueous solution onto Acrocomia aculeata pulp was examined. The pulp was characterized in the presence and absence of lead using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG-DTA), and scanning electron microscopy (SEM). Sulfur and oxygen bonds were responsible for adsorbing lead onto the pulp surface. The TG-DTA profile proved that adding sodium azide increases the pulp�s thermal stability until 200 �C. Adsorption data in batch and column systems were analyzed to understand the pulp adsorption compared to other biomaterials. In the batch experiments, the removal efficiency reached a maximum of 91.9% when a solution of 50 ppm of lead was placed in contact with the pulp for 30 min and fit Freundlich isotherm behavior. In the column experiments, the theoretical maximum adsorption capacity was found to be 11.97 mg g�1; more column data is needed to compare column results to other studies. Further studies to improve the pulp adsorption capacity are needed for it to be a competitive biomaterial for water treatment.

Thermodynamic Studies for Adsorption of Cd2+ and Pb2+ from Waster Water on Modified Walnut Shell

2015 ◽  
Vol 737 ◽  
pp. 622-626
Author(s):  
Shao Hua He ◽  
Dan Wang ◽  
Qing Qiu Kong ◽  
Xi Wu
Keyword(s):  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Walnut Shell ◽  
Isotherm Models ◽  
Model Parameters ◽  
Maximum Adsorption Capacity ◽  
Adsorption Data ◽  
Batch Technique ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model

The adsorption isothermal curve and thermodynamic adsorption of Cd2+ and Pb2+ on modified walnut shell from waster water were investigated using batch technique. The equilibrium adsorption data are fitted to Langmuir and Freundlich isotherm models and the model parameters are evaluated. The Langmuir isotherm model shows a better fit to adsorption data than the Freundlich isotherm model for the sorption of Cd2+ and Pb2+ on modified walnut shell. The maximum adsorption capacity of Cd2+ and Pb2+ by modified walnut shell is found to be 32.68 mg·g-1 and 84.75 mg·g-1 at 298K temperature, respectively. The adsorption processes of Cd2+ and Pb2+ has feasibility and spontaneous nature. Thermodynamic parameters depict the endothermic nature of sorption and the process is spontaneous and favorable.

scholarly journals Removal of Pb(II) from Aqueous Solution by Ceramsite Prepared from Isfahan Bentonite and γ-Alumina

2021 ◽  
Vol 15 (2) ◽  
pp. 263-273
Author(s):  
Iman Mobasherpour ◽  
◽  
Masomeh Javaherai ◽  
Esmail Salahi ◽  
Mohsen Ebrahimi ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
The Novel ◽  
Absorption Process ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Adsorption Data ◽  
Ft Ir ◽  
Central Composite

Removal of lead from aqueous solutions was studied using nanocomposite absorbent of bentonite/-alumina. The novel absorbent was characterized using XRD, FT-IR and SEM-EDX. Absorption process optimization using response surface methodology (RSM) and experimental design was performed with central composite design technique. The effects of Pb(II) initial concentration, adsorbent dosage, and composite percentage on Pb(II) removal percentage and adsorption capacity were examined. The adsorption capacity of 166.559 mg/g and removal % of 82.9887 with desirability equal to 0.763 were obtained for optimal initial concentration of 200 mg•l-1, adsorbent dosage of 0.5 mg•l-1, and composite percentage of 7.08 % determined using RSM design. The equilibrium adsorption data were investigated by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. It was found that Freundlich isotherm model fits better compared with other models.

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