scholarly journals Adsorption kinetic characteristics of molybdenum in yellow-brown soil in response to pH and phosphate

2020 ◽  
Vol 18 (1) ◽  
pp. 663-668
Author(s):  
Zhaojun Nie ◽  
Jinfeng Li ◽  
Haiyang Liu ◽  
Shiliang Liu ◽  
Daichang Wang ◽  
...  
Keyword(s):  
Competitive Adsorption ◽  
Adsorption Kinetic ◽  
Kinetic Characteristics ◽  
Sorption Data ◽  
Equilibrium Sorption ◽  
Brown Soil ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Langmuir Isotherm Model ◽  
Ph Range

AbstractMolybdenum (Mo) adsorption by acidic yellow-brown soil was investigated as a function of a pH (1–13) and the equilibrium of P solution (0, 3.1, and 31 mg L−1) concentration. Mo adsorption by acidic yellow-brown soil increased within the pH range from 1 to 4. Above pH 4, Mo adsorption decreases with an increase in pH. The maximum adsorption was found between pH 2 and 4. Competitive adsorption experiments showed that the equilibrium sorption data fitted into Langmuir and Freundlich isotherms. The sorption data of Mo on the acidic yellow-brown soil fitted well with the Langmuir isotherm model due to the higher R2 value. A reduction in Mo adsorption by the acidic yellow-brown soil was noticed at higher addition levels of P (3.1 and 31 mg L−1). Therefore, P increasing the bioavailability of Mo and enhancing Mo uptake by plants might be related to the inhibition of Mo absorption by the acidic yellow-brown soil.

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.

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.

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 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 Properties of Thermally Treated Rice Husk for Removal of Sulfamethazine Antibiotic from Pharmaceutical Wastewater

2020 ◽  
pp. 84-92
Author(s):  
Davoud Balarak ◽  
Fatemeh Bandani ◽  
Zaccheus Shehu ◽  
Nehad J. Ahmed
Keyword(s):  
Rice Husk ◽  
Langmuir Isotherm ◽  
Chemical Properties ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Sorption Data ◽  
Equilibrium Sorption ◽  
Langmuir Isotherm Model ◽  
Sorption Intensity ◽  
Thermally Treated

Equilibrium sorption of the Thermally Treated Rice Husk (TTRH) for Sulfamethazine (SMT) adsorption was studied. The Physico-chemical properties of the modified rice husk were determined. The equilibrium sorption data were fitted into Langmuir, Freundlich and Dubinin–Radushkevich isotherms. Of the three adsorption isotherm, the R2 value of Langmuir isotherm model was the highest. Also compared to other isotherms the AARE coefficient for the Langmuir isotherm is low, which indicates favorable sorption. The maximum monolayer coverage (qm) from Langmuir isotherm model was determined to be 19.11 mg/g, the separation factor indicating a favorable sorption experiment is 0.446. Also from Freundlich Isotherm model, the sorption intensity (n) which indicates favorable sorption and the correlation value are 1.84 and 3.79 respectively. The mean free energy was estimated from Dubinin–Radushkevich isotherm model to be 9.18 KJ/mol which clearly proved that the adsorption experiment followed a physical process.

scholarly journals Sorption of phosphates and thiocyanates on isomorphic substituted Mg/Zn-Al-type hydrotalcites

2008 ◽  
Vol 73 (8-9) ◽  
pp. 835-843 ◽  
Author(s):  
Rodica Pode ◽  
Eveline Popovici ◽  
Laura Cocheci ◽  
Erika Reisz ◽  
Mihaela Seftel ◽  
...  
Keyword(s):  
Gibbs Energy ◽  
Standard Gibbs Energy ◽  
Physical Adsorption ◽  
Freundlich Isotherm ◽  
Sorption Data ◽  
Freundlich Isotherms ◽  
Data Standard ◽  
Langmuir And Freundlich Isotherms ◽  
Maximum Sorption ◽  
Equilibrium Data

The sorption equilibriums of phosphate and thiocyanate anions on isomorphic substituted Mg/Zn-Al-type hydrotalcites were investigated in this study. Langmuir and Freundlich isotherms were used to interpret the equilibrium data for phosphate. The sorption equilibriums of phosphate on Mg3Al, Mg2ZnAl and Mg1.5Zn1.5Al hydrotalcites were well described by the Langmuir isotherm. The highest maximum sorption capacities for these adsorbents were as follows: 111, 101 and 95 mg g-1. The equilibrium constant and standard Gibbs energy changes were also calculated from the sorption data. Standard Gibbs energy changes of about -20 kJ mol-1 indicated that the process might be considered as physical adsorption. The sorption equilibriums of phosphate on isomorphic substituted samples of MgZn2Al and Zn3Al were well described by the Freundlich isotherm. Thiocyanate showed a relative low affinity for the studied materials, as indicated by both the 'S'-shaped isotherms and low sorption capacities. The sorption of phosphate and thiocyanate on the investigated hydrotalcites showed a continuous decrease of the sorption capacity in the following order: Mg3Al > Mg2ZnAl > Mg1.5Zn1.5Al > MgZn2Al > Zn3Al.

Removal of Ni(II) from aqueous solution using Moringa oleifera seeds as a bioadsorbent

2012 ◽  
Vol 65 (8) ◽  
pp. 1435-1440 ◽  
Author(s):  
Thiago L. Marques ◽  
Vanessa N. Alves ◽  
Luciana M. Coelho ◽  
Nívia M. M. Coelho
Keyword(s):  
Moringa Oleifera ◽  
Low Cost ◽  
Ease Of Use ◽  
Toxic Waste ◽  
Adsorption Model ◽  
New Techniques ◽  
Sorption Data ◽  
Natural Adsorbents ◽  
Ph Range

Metal contaminants are generally removed from effluents by chemical and physical processes which are often associated with disadvantages such as the use of toxic reagents, generation of toxic waste and high costs. Hence, new techniques have been developed, among them the study of natural adsorbents, for instance, the use of Moringa oleifera seeds. The potential of M. oleifera seeds for nickel removal in aqueous systems was investigated. The seeds utilized were obtained from plants grown in Uberlândia/Brazil. After being dried and pulverized, the seeds were treated with 0.1 mol/L NaOH. Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analyses were used for the characterization of the material. Using the optimized methodology (50 mL of 4.0 mg/L Ni(II), pH range of 4.0–6.0, agitation time of 5 min and adsorption mass of 2.0 g) more than 90% of Ni(II) could be removed from water samples. The sorption data were fitted satisfactorily by the Langmuir adsorption model. Evaluation applying the Langmuir equation gave the monolayer sorption capacity as 29.6 mg/g. The results indicate that this material could be employed in the extraction of nickel, considering its ease of use, low cost and environmental viability, which make it highly attractive for application in developing countries.

scholarly journals Adsorption of strontium on different sodium-enriched bentonites

2017 ◽  
Vol 82 (4) ◽  
pp. 449-463 ◽  
Author(s):  
Sanja Marinovic ◽  
Marija Ajdukovic ◽  
Natasa Jovic-Jovicic ◽  
Tihana Mudrinic ◽  
Bojana Nedic-Vasiljevic ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Adsorption Capacity ◽  
Textural Properties ◽  
X Ray Diffraction ◽  
Order Model ◽  
Surface Areas ◽  
Alkaline Conditions ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Range

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0?8.5, the amount of adsorbed Sr2+ was almost constant but 2?3 times smaller than at pH ?11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin?Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.

scholarly journals Sorption of Ni(II) and Cr(III) ions by the Chironomus yoshimatsui larvae from wastewater

2018 ◽  
Vol 15 (1) ◽  
pp. 6062-6069
Author(s):  
Keon Sang Ryoo
Keyword(s):  
Freundlich Isotherm ◽  
Sorption Kinetics ◽  
Isotherm Model ◽  
Sorption Data ◽  
First Order ◽  
Batch System ◽  
Survival Capacity ◽  
Langmuir Isotherm Model ◽  
Treatment Technologies ◽  
Kinetics Of

In this study, Chironomus yoshimatsui larvae were applied to remove Ni(II) and Cr(III) ions from wastewater. The sorption studies were carried out using laboratory-reared C. y. larvae. It was found that C. y. larvae are very susceptible to Cr(III) as compared to Ni(II). The survival capacity of C. y. larvae was sharply reduced when exposed to even low Cr(III) concentration. Sorption isotherm and kinetics of C. y. larvae for Ni(II) were determined by means of controlled experiments in a batch system. It was observed that sorpyion efficiency of Ni(II) was largely concentration dependent and more effective at lower concentration. At each equilibrium, Ni(II) was removed up to roughly 44∼80 %. Sorption data were better fitted to the Langmuir isotherm model because of its correlation coefficient R2 value greater than that of the Freundlich isotherm model. The sorption kinetics by C. y. larvae for Ni(II) was well described a pseudo-first-order rate expression. C. y. larvae have enormous potential for application in wastewater treatment technologies because they are widespread and abundant all around the world and can be easily kept in culture.

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