scholarly journals Adsorption of U(VI) from Aqueous Solution onto Hydrotalcite-Like Compounds

2012 ◽  
Vol 9 (2) ◽  
pp. 669-679 ◽  
Author(s):  
Nguyen Van Suc
Keyword(s):  
Adsorption Capacity ◽  
Enthalpy Change ◽  
Time Dependent ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Equilibrium Data ◽  
Endothermic Process ◽  
Ph Range ◽  
Initial Adsorption ◽  
Hydroxide Hydrate

Uranium adsorption by the synthesized compound of magnesium aluminum hydroxide hydrate – layered double hydrotalcite (STH)-like compounds was studied. The calcinated STH was proven to be a highly effective in U(VI) adsorption in pH range from 6.5 to 7. The time dependent experimental data were found to be fit to the pseudo-second-oder model. The equilibrium data have been modeled using Langmuir and Freundlich isotherms. The results showed that both model provide the best correlation with equilibrium data. The highest adsorption capacity, approximated 62.5 mg/g, was observed in the calcinated STH at 500 °C. The positive value of enthalpy change indicated that adsorption reaction of U(VI) on STH was endothermic process. The regeneration experiments of STH using 0.1M Na2CO3solution was successfully demonstrated multiple times without any significant effect on the initial adsorption capacity.

Evaluation of the Adsorption of Cr(VI) by Modified Bamboo Shells

2013 ◽  
Vol 361-363 ◽  
pp. 709-715
Author(s):  
Xin Long Jiang ◽  
Yi Hua Jiang
Keyword(s):  
Activation Energy ◽  
Adsorption Capacity ◽  
Chemical Process ◽  
Chemical Methods ◽  
Ir Spectrometry ◽  
Film Diffusion ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Negligible Influence ◽  
Adsorption Activation Energy

The adsorption of Cr(VI) by modified Bamboo shell has been investigated using chemical methods and IR spectrometry. The optimal condition for the adsorption of Cr(VI) by modified Bamboo shell is at 298 K and pH = 1.0, which gives a static saturated adsorption capacity of 12.68 mg·g-1, an apparent adsorption rate constant of k298 = 9.56 × 10-4 s-1, and an apparent adsorption activation energy of 7.38 kJ·mol-1. The adsorption follows the Langmuir and Freundlich isotherms and the liquid film diffusion is the controlling process of the adsorption. The adsorption thermodynamic parameters are ΔH = 66.04 kJ·mol-1, ΔS = 0.2974 kJ·mol-1·K-1, ΔG = −22.58~−28.52 kJ·mol-1. The anions HPO42-, H2PO4- and SO42- have negligible influence on the adsorption capacity. Small amount of desorption is observed only at pH > 11. The adsorption of Cr(VI) by modified bamboo shell is mainly a chemical process.

Ultrasonic Treatment of Activated Carbon Used in Adsorption of Basic Fuchsin

2011 ◽  
Vol 704-705 ◽  
pp. 486-491
Author(s):  
Yi Nan Hao ◽  
Xi Ming Wang ◽  
Li Jun Ding ◽  
Da Yan Ma
Keyword(s):  
Activated Carbon ◽  
Contact Time ◽  
Equilibrium Concentration ◽  
Acid Activation ◽  
Basic Fuchsin ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Different Temperatures ◽  
Endothermic Process ◽  
Pseudo Second Order

Xanthoceras Sorbifolia Bunge hull activated carbon (XSBHAC) developed by phosphoric acid activation for removing basic fuchsin (BF) has been investigated. Experiments were carried out as function of contact time, pH (4-10) and temperature (303,313 and 323K). Adsorption isotherms were modeled with the Langmuir and Freundlich isotherms. The data fitted well with the Langmuir isotherm. The Langmuir monolayer saturation capacities of BF adsorbed onto activated carbon were 351.35, 354.96 and 355.94 mg/g at 303,313, and 323 K, respectively.The kinetic models were also studied .The rates of adsorption were found to conform to the pseudo-second-order kinetics with good correlation.Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters,such as △G,△H and △S, have been calculated. The thermodynamics parameters of system indicated spontaneous and endothermic process. Key words: Xanthoceras sorbifolia bunge hull;biosorption; basic fuchsin

scholarly journals Arsenic removal from water by Zr-γ- FeOOH nanoparticles

2019 ◽  
Vol 2 (1) ◽  
pp. 112-120
Author(s):  
Nguyen Dinh Trung ◽  
Le Thi Ha Lan
Keyword(s):  
Ammonium Chloride ◽  
Arsenic Removal ◽  
Precipitation Method ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Adsorption Data ◽  
Wide Ph Range ◽  
Ph Range ◽  
Co Precipitation ◽  
Competitive Ions

Zr-γ-FeOOH nanoparticle adsorbent for As(V) and As(III) removal was prepared by a chemical co-precipitation method. Compared with γ-FeOOH, the addition of Zr enhanced the adsorptive capacities of As(V) and As(III). The maximum adsorptive capacities for As(V) and As(III) were 69.81 and 94.25 mg/g, respectively (rate Fe:Zr =1:0.5) at pH= 7.0. The adsorption data accorded with Langmuir and Freundlich isotherms. The adsorption of As(III) by Zr- γ-FeOOH was found to be effective in wide pH range of 6–8. Competitive ions hindered the adsorption according to the decreasing sequence phosphate, sulfate, ammonium, chloride, magnesium and calcium. The high adsorptive capability and good performance on other aspects make the Zr-γ- FeOOH nanorods a promissing adsorbent for the removal of As(V) and As(III) from groundwater.

Application of Chitosan Film for the Removal of Triclosan from Aqueous Solutions by Adsorption

2016 ◽  
Vol 675-676 ◽  
pp. 455-458
Author(s):  
Peeyanan Noirod ◽  
Jittapat Lamangthong ◽  
Padarat Ninjiaranai
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Chitosan Film ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Acidic Ph ◽  
Adsorption Efficiency ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Equilibrium Data

The aim of this work was to study the adsorption efficiency of chitosan as an adsorbent for triclosan, commercially known as Irgasan, in aqueous solutions. The effects of contact time, pH and temperature were investigated using a batch adsorption technique. Langmuir and Freundlich isotherms were used to analyze the equilibrium data at different absorption conditions. The results showed that the maximum adsorption capacity for chitosan was found in the acidic pH 3 and at a temperature of 65 oC. These results suggested that chitosan can be used as an adsorbent for removal of triclosan from aqueous solutions.

scholarly journals Adsorption of Cu(II) by Poly-γ-glutamate/Apatite Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 962
Author(s):  
Kuo-Yu Chen ◽  
Wei-Yu Zeng
Keyword(s):  
Adsorption Capacity ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
Solution Ph ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Initial Adsorption ◽  
Adsorption Equilibrium Data

Poly-γ-glutamate/apatite (PGA-AP) nanoparticles were prepared by chemical coprecipitation method in the presence of various concentrations of poly-γ-glutamate (γ-PGA). Powder X-ray diffraction pattern and energy-dispersive spectroscopy revealed that the main crystal phase of PGA-AP was hydroxyapatite. The immobilization of γ-PGA on PGA-AP was confirmed by Fourier transform infrared spectroscopy and the relative amount of γ-PGA incorporation into PGA-AP was determined by thermal gravimetric analysis. Dynamic light scattering measurements indicated that the particle size of PGA-AP nanoparticles increased remarkably with the decrease of γ-PGA content. The adsorption of aqueous Cu(II) onto the PGA-AP nanoparticles was investigated in batch experiments with varying contact time, solution pH and temperature. Results illustrated that the adsorption of Cu(II) was very rapid during the initial adsorption period. The adsorption capacity of PGA-AP nanoparticles for Cu(II) was increased with the increase in the γ-PGA content, solution pH and temperature. At a pH of 6 and 60 °C, a higher equilibrium adsorption capacity of about 74.80 mg/g was obtained. The kinetic studies indicated that Cu(II) adsorption onto PGA-AP nanoparticles obeyed well the pseudo-second order model. The Langmuir isotherm model was fitted well to the adsorption equilibrium data. The results indicated that the adsorption behavior of PGA-AP nanoparticles for Cu(II) was mainly a monolayer chemical adsorption process. The maximum adsorption capacity of PGA-AP nanoparticles was estimated to be 78.99 mg/g.

Adsorption of Copper Ions from Aqueous Solutions by Chitin

2012 ◽  
Vol 550-553 ◽  
pp. 2424-2427
Author(s):  
Chung Hsin Wu ◽  
Chao Yin Kuo ◽  
Meng Jia Chen
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Linear Correlation ◽  
Langmuir Isotherm ◽  
Copper Ions ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Better Than

This study utilizes chitin to remove dissolved Cu(II) from aqueous solutions. The effects of the dissolved Cu(II) concentration, chitin dosage, and pH on adsorption of dissolved Cu(II) by chitin are determined. Adsorption capacity for 20 and 80 mg/L dissolved Cu(II) onto chitin (2 g/L) was 3.86 mg/g and 5.12 mg/g, respectively. The dissolved Cu(II) adsorption percentage increased from 39% to 70% when the chitin dosage was increased from 2 g/L to 4 g/L. The linear correlation coefficients of Langmuir and Freundlich isotherms were obtained. Analytical results demonstrate that the Freundlich isotherm fitted experimental results better than did the Langmuir isotherm. Enthalpy (ΔH0) and entropy (ΔS0) for dissolved Cu(II) adsorption were 8.46 kJ/mol and 123.1 J/mol.K, respectively.

Competitive Adsorption of Lead and Copper by Kaolin

2014 ◽  
Vol 1073-1076 ◽  
pp. 784-790
Author(s):  
Obed Osei Anokye ◽  
Chun Lei Zhang
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Competitive Adsorption ◽  
Binary Solution ◽  
Maximum Adsorption Capacity ◽  
Metal Solution ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Removal Of Heavy Metals ◽  
Separation Factors

Due to the potential of kaolin as an adsorbent for removal of heavy metals from solution, the competitive adsorption of Lead (Pb) and Copper (Cu) by kaolin was investigated to provide further understanding on the binding behaviors and capacities of these two metals onto kaolin. The Langmuir and Freundlich isotherms were applied to further explain the competition between the metals. Three different solutions were used, each at concentrations 10, 20, 30, 45, 60 and 75mg/L: single-metal solution of Pb (Pb-Only), single-metal solution of Cu (Cu-Only), and solution of both metals at the same concentrations (Binary solution). The kaolin adsorbed Pb about twice more than Cu, both for the binary solution and for the single-metal solutions. This correlated well with predictions of maximum adsorption capacity (Q) for kaolin, where Q for Pb was about twice as much as that for Cu, both in the binary solution and in the single-metal solution. Competition from Cu in binary solution reduced Pb adsorption by 9%, while Cu rather increased by 4.1%, relative to their respective adsorptions in Pb-Only and Cu-Only, respectively. However, during competitive adsorption in the binary solution, the relative proportions of adsorbed Pb increased by 11.4% as the initial metals concentration increased from 10 – 75mg/L, while that of Cu reduced by the same proportion. This was explainable by their respective separation factors (RL), which indicated higher favorability of kaolin for Pb than for Cu. Furthermore, bonding energy (KL) of Pb unto kaolin during competition was about 2.5 times that of Cu, and was likely able to cause Pb to displace Cu from kaolin surface. This study reveals greater adsorption capacity of kaolin for Pb than for Cu, and could provide the basis for future projects/studies that would employ kaolin in Pb and Cu removal.

scholarly journals Cr(VI) Removal from Wastewater by Using Rice Husk Ash (RHA)

2006 ◽  
Vol 6 (1) ◽  
pp. 53
Author(s):  
M. J. Uddin ◽  
M. M.R. Khan ◽  
M S. Iftekhar ◽  
M A Islam
Keyword(s):  
Rice Husk ◽  
Optimum Parameter ◽  
Rice Husk Ash ◽  
Toxic Metal ◽  
Synthetic Wastewater ◽  
Tannery Effluent ◽  
Freundlich Isotherms ◽  
Chromium Vi ◽  
Langmuir And Freundlich Isotherms ◽  
Equilibrium Data

Rice husk ash (RHA) was studied as a potential adsorbent for Chromium (VI)removal from wastewater. RHA was able to remove effectively and economically toxic metal from synthetic wastewater. Experiments were done on the removal of Cr(VI) from dichromate solution which is a form of chromium in tannery effluent. The amount of Cr(VI) adsorption increased with the decrease in pH. The optimum parameter was = 2.0 evaluated at pH and the dose rate of the adsorbent was 5 kg RHNm3. The equilibrium data fit well in both the Langmuir and Freundlich isotherms. The study showed that 89.29 x 10-3kg Cr(VI) could be removed by 1 Kg of RHA. Since rice husk (RH) is available and cheap in Bangladesh, it can be used easily as an appropriate adsorbent to remove more than 95% Cr(VI) from tannery wastewater.

scholarly journals Removal of Sb(III) and Sb(V) from aqueous media by goethite

2013 ◽  
Vol 48 (3) ◽  
pp. 223-231 ◽  
Author(s):  
Jianhong Xi ◽  
Mengchang He
Keyword(s):  
Reaction Time ◽  
Thermodynamic Parameters ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Kinetic Studies ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Adsorption Data ◽  
Different Temperatures ◽  
Ph Range

This study investigated the removal of Sb(III) and Sb(V) from aqueous media through their adsorption onto oxide minerals (goethite) under a set of conditions (initial Sb concentration, pH, reaction time, and interaction temperature). The kinetic studies suggested that the adsorption equilibriums for both Sb(III) and Sb(V) were achieved within 24 h. The adsorption data collected at three different temperatures were successfully modeled using both the Langmuir and Freundlich isotherms. The adsorption of Sb(III) onto goethite was greater than that of Sb(V) at the three investigated temperatures. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were calculated from the dependence of the adsorption process on the reaction temperature, and the calculated parameters suggest that the adsorption of both Sb(III) and Sb(V) onto goethite is spontaneously endothermic. The adsorption of Sb(III) and Sb(V) on goethite was dependent on pH within the investigated pH range.

scholarly journals Adsorption of Aqueous As (III) in Presence of Coexisting Ions by a Green Fe-Modified W Zeolite

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 281 ◽  
Author(s):  
Adriana Medina-Ramirez ◽  
Procoro Gamero-Melo ◽  
Beatriz Ruiz-Camacho ◽  
Jesus Isaac Minchaca-Mojica ◽  
Rafael Romero-Toledo ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Low Cost ◽  
Underground Water ◽  
Ferrous Chloride ◽  
Removal Capacity ◽  
Endothermic Process ◽  
Arsenite Removal ◽  
Ph Range ◽  
Coexisting Ions

The high toxicity of arsenite and the difficulty to remove it is one of the main challenges for water treatment. In the present work the surface of a low cost zeolite was modified by chemical treatment with a ferrous chloride to enhance its arsenite adsorption capacity. The effect of pH, ions coexistence, concentration, temperature and dosage was studied on the adsorption process. Additionally, the Fe-modified W zeolite was aged by an accelerated procedure and the regeneration of the exhausted zeolite was demonstrated. The Fe-modified W zeolite was stable in the pH range of 3 to 8 and no detriment to its arsenite removal capacity was observed in the presence of coexisting ions commonly found in underground water. The studies showed that the adsorption of As (III) on Fe-modified W zeolite is a feasible, spontaneous and endothermic process and it takes place by chemical bonding. The exhausting process proved the adsorption of 0.20 mg g−1 of As (III) by the Fe-modified W zeolite and this withstand at least five aging cycles without significant changes of its arsenite adsorption capacity. Fe-modified W zeolite prepared from fly ash might be a green and low-cost alternative for removal of As (III) from groundwater.

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