Adsorption of Fluoride on Limestone-Derived Apatite

2012 ◽  
pp. 128-138
Author(s):  
Cyprian Murutu ◽  
Maurice S. Onyango ◽  
Aoyi Ochieng ◽  
Fred Otieno
Keyword(s):  
Drinking Water ◽  
Adsorption Capacity ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Dental And Skeletal Fluorosis ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Permissible Levels ◽  
Ph Range

Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. Adsorptive based defluoridation is the most popular technique with several end-user applications. Consequently, this paper describes the fluoride removal potential of a novel sorbent, limestone-derived apatite from drinking water. The adsorbent was prepared by calcining limestone followed by reacting with orthophosphoric acid. Batch sorption studies were performed as a function of contact time, pH, initial fluoride concentration, temperature and adsorbent dose. Sorption of fluoride was found to be pH dependent with a maximum occurring in the pH range of 5-9. The authors also observed that the material had a buffering effect on the same pH range. Meanwhile, the adsorption capacity was found to increase with temperature, depicting the endothermic nature of the adsorption process and decreases with adsorbent mass. The equilibrium data was well described by the conventional Langmuir isotherm, from which isotherm the maximum adsorption capacity was determined as 22.2 mg/g. From the kinetic perspective, the fluoride adsorptive reaction followed the pseudo-second order mechanism.

Adsorption of Fluoride on Limestone-Derived Apatite

2010 ◽  
Vol 1 (3) ◽  
pp. 13-22 ◽  
Author(s):  
Cyprian Murutu ◽  
Maurice S. Onyango ◽  
Aoyi Ochieng ◽  
Fred Otieno
Keyword(s):  
Drinking Water ◽  
Adsorption Capacity ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Dental And Skeletal Fluorosis ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Permissible Levels ◽  
Ph Range

Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. Adsorptive based defluoridation is the most popular technique with several end-user applications. Consequently, this paper describes the fluoride removal potential of a novel sorbent, limestone-derived apatite from drinking water. The adsorbent was prepared by calcining limestone followed by reacting with orthophosphoric acid. Batch sorption studies were performed as a function of contact time, pH, initial fluoride concentration, temperature and adsorbent dose. Sorption of fluoride was found to be pH dependent with a maximum occurring in the pH range of 5-9. The authors also observed that the material had a buffering effect on the same pH range. Meanwhile, the adsorption capacity was found to increase with temperature, depicting the endothermic nature of the adsorption process and decreases with adsorbent mass. The equilibrium data was well described by the conventional Langmuir isotherm, from which isotherm the maximum adsorption capacity was determined as 22.2 mg/g. From the kinetic perspective, the fluoride adsorptive reaction followed the pseudo-second order mechanism.

Adsorption kinetics and thermodynamics of acid Bordeaux B from aqueous solution by graphene oxide/PAMAMs

2015 ◽  
Vol 72 (7) ◽  
pp. 1217-1225 ◽  
Author(s):  
Fan Zhang ◽  
Shengfu He ◽  
Chen Zhang ◽  
Zhiyuan Peng
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Freundlich Model ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Effects Of Media ◽  
Better Than

Graphene oxide/polyamidoamines dendrimers (GO/PAMAMs) composites were synthesized via modifying GO with 2.0 G PAMAM. The adsorption behavior of the GO/PAMAMs for acid Bordeaux B (ABB) was studied and the effects of media pH, adsorption time and initial ABB concentration on adsorption capacity of the adsorbent were investigated. The optimum pH value of the adsorption of ABB onto GO/PAMAMs was 2.5. The maximum adsorption capacity increased from 325.78 to 520.83 mg/g with the increase in temperature from 298 to 328 K. The equilibrium data followed the Langmuir isotherm model better than the Freundlich model. The kinetic study illustrated that the adsorption of ABB onto GO/PAMAMs fit the pseudo-second-order model. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.

Fluoride Removal of a Novel Ultrasonic-Assisted Supported Fe/γ-Al2O3 Adsorbent

2013 ◽  
Vol 316-317 ◽  
pp. 387-390 ◽  
Author(s):  
Wen Hui Zou ◽  
Yong Liu ◽  
Li Hong ◽  
Zhong Yu Luo
Keyword(s):  
Fluoride Concentration ◽  
Column Experiment ◽  
Space Velocity ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Sem Images ◽  
Fluoride Adsorption ◽  
Actual Application ◽  
Ultrasonic Assisted ◽  
Ph Range

Ultrasonic-assisted supported Fe/γ-Al2O3, fluoride; γ-Al2O3; adsorption Abstract: γ-Al2O3 adsorbent modified with iron (Fe/γ-Al2O3) was prepared by impregnation and ultrasonic wave-assisted oxidation. The optimum pH range for fluoride adsorption was 3.0–9.0, which is preferable for actual application. The maximum adsorption capacity of the Fe/γ-Al2O3 adsorbent was 2.51 mg g-1 and about 2 times of the plain γ-Al2O3 (γ-Al2O3). A column experiment was performed at an initial fluoride concentration of 30 mg l-1, space velocity of 1.7 h-1 and pH of 5.9, and the breakthrough time of the Fe/γ-Al2O3 was more than 210 min with the effluent fluoride under 10 mg l-l and was about 5 times of the plain one. The samples were measured by X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images.

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.

scholarly journals Adsorption Efficiency of Cement Impregnated Magnesium Oxide on the Removal of Fluoride

2020 ◽  
Vol 5 (2) ◽  
pp. 109-117
Author(s):  
Iohborlang M. Umlong ◽  
Bodhaditya Das ◽  
Rashmi Rekha Devi
Keyword(s):  
Drinking Water ◽  
Magnesium Oxide ◽  
Fluoride Concentration ◽  
Sorption Process ◽  
Fluoride Removal ◽  
Cement Slurry ◽  
Freundlich Isotherms ◽  
Removal Capacity ◽  
Complex Process ◽  
Pseudo Second Order

Presence of fluoride in drinking water above the prescribed limit may lead to a severe health complication. We present in this paper the fluoride removal capacity of cement impregnated MgO (MgO-cement) from drinking water. MgO-cement was prepared by adding magnesium oxide (MgO) into the cement slurry solution in the ratio of 1:10. Batch experiments were performed as a function of adsorbent dose, contact time, effect of pH and effect of co-ions. The percentage removal decreases with increasing initial fluoride concentration. Co-ions effect revealed that hydroxide ion was found to interfere more with fluoride removal followed by bicarbonate and least effect with sulphate. Reaction mechanism follows Freundlich isotherms. From the kinetic study we observed that uptake of fluoride ion is fast in the first sixty minutes and equilibrium time found to be independent of the initial fluoride concentration. Adsorption kinetics followed the pseudo second order model showing that the sorption of fluoride is a complex process. Surface as well as intraparticle diffusion contribute in the sorption process. No leaching of magnesium in the treated water was detected.

scholarly journals Enhanced fluoride removal from drinking water in wide pH range using La/Fe/Al oxides loaded rice straw biochar

2021 ◽  
Author(s):  
Nan Zhou ◽  
Xiangxin Guo ◽  
Changqing Ye ◽  
Ling Yan ◽  
Weishi Gu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Rice Straw ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Adsorption Sites ◽  
Wide Ph Range ◽  
Rice Straw Biochar ◽  
Ph Range

Abstract A novel and highly efficient adsorbent was prepared by loading La/Fe/Al oxides onto rice straw biochar (RSBC) and was tested for the ability to remove fluoride from drinking water. Characterized by SEM, XRD, Zetapotential and FTIR, it was found that the ternary metal oxides were successfully loaded on the surface of biochar in amorphous form, resulting in the formation of hydroxyl active adsorption sites and positive charges, which played a synergistic role in fluoride removal. Through batch adsorption tests, key factors including contact time, initial fluoride concentration, initial pH and co-existing anions effects were investigated. Results showed that the tri-metallic modified biochar (La/Fe/Al-RSBC) had excellent fluoride removal performance with an adsorption capacity of 111.11 mg/g. Solution pH had little impacts on the removal of fluoride, the adsorbent retained excellent fluoride removal capacity in a wide pH range of 3.0–11.0. The co-existing anions had almost no effect on the fluoride removal by La/Fe/Al-RSBC. In addition, La/Fe/Al-RSBC could be regenerated and reused. Electrostatic adsorption and ion exchange were responsible for this adsorption behavior. These findings suggested the broad application prospect of a prepared biochar adsorbent based on rare earth and aluminum impregnation for the fluoride removal from drinking water.

Magnetic nanopowder as effective adsorbent for the removal of Congo Red from aqueous solution

2013 ◽  
Vol 69 (6) ◽  
pp. 1234-1240 ◽  
Author(s):  
O. Paşka ◽  
R. Ianoş ◽  
C. Păcurariu ◽  
A. Brădeanu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Congo Red ◽  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Anionic Dyes ◽  
Solution Ph ◽  
Efficient Combustion ◽  
Equilibrium Data ◽  
Pseudo Second Order

A magnetic iron oxide nanopowder (MnP), prepared by a simple and efficient combustion synthesis technique, was tested for the removal of the anionic dye Congo Red (CR) from aqueous solution. The influence of solution pH, adsorbent dose, temperature, contact time and initial dye concentration on the adsorption of CR onto MnP were investigated. It was shown that the CR adsorption was pH dependent and the adsorption mechanism was governed by electrostatic forces. The adsorption kinetic was best described by the pseudo-second-order model and the equilibrium data were well fitted to the Langmuir isotherm, yielding maximum adsorption capacity of 54.46 mg g−1. The undeniable advantages of the MnP adsorbent such as inexpensive preparation method, good adsorption capacity and easy separation using an external magnetic field, recommend it as a promising candidate for the removal of anionic dyes from polluted water.

scholarly journals Lithium Biosorption by Arthrospira (Spirulina) Platensis Biomass

2020 ◽  
Vol 27 (2) ◽  
pp. 271-280
Author(s):  
Inga Zinicovscaia ◽  
Nikita Yushin ◽  
Ana Pantelica ◽  
Štefan Demčák ◽  
Andreea Mitu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Arthrospira Platensis ◽  
Maximum Adsorption Capacity ◽  
Lithium Content ◽  
Order Kinetic ◽  
Gamma Emission ◽  
Batch Systems ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

AbstractThe biosorption of lithium from batch systems by Arthrospira (Spirulina) platensis biomass was studied. Adsorption capacity of the biosorbent was investigated as a function of contact time, initial metals concentration and pH values. Lithium content in biomass was determined using Proton Induced Gamma Emission technique. The ability of spirulina biomass for lithium biosorption showed a maximum at the pH = 11. Equilibrium data fitted well with the Langmuir model with maximum adsorption capacity of 1.75 mg/g, while the kinetic data were best described using the pseudo second-order kinetic model. The IR spectrum of the Li-loaded biomass revealed that lithium ions could be primarily bind to –OH, –COOH, –NH, –NH2, and –NH3 groups present on biosorbent surface. Arthrospira platensis biomass could be applied as environmentally friendly sorbent for lithium removal from wastewater.

Isotherm and Kinetics Modeling of Fluoride Removal from Industrial Effluent by Alumina

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Z. V. P. Murthy ◽  
Telu Prabhakar ◽  
Raj Kumar
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Kinetic Models ◽  
Fluoride Concentration ◽  
Industrial Effluent ◽  
Second Order ◽  
Fluoride Removal ◽  
Wide Range ◽  
Pseudo Second Order ◽  
High Level

Fluoride contamination occurs in a wide range of industrial wastewater that has to be regulated from time to time. In the present study, wastewater from a polybutadiene rubber plant of Indian Petrochemicals Corporation Limited, Vadodara, Gujarat, India with a higher temperature, acidic pH and high level of fluoride concentration is treated with alumina. The contact time between the adsorbent and the adsorbate should be sufficient for the adsorption to be effective. Though synthetic resins have good adsorption capacity for the wastewater, they have some disadvantages; therefore, alumina has been tried. Properties of alumina, such as pH, bulk density, surface area, pore specific volume, and bulk crushing strength, have been found. Adsorption by alumina is found to be favorable. Five equilibrium adsorption isotherms, viz. Freundlich, Langmuir, Temkin, Harkins-Jura and Halsey, have been tested. It is found that the Halsey and Freundlich adsorption isotherms are fitting the data well. Four kinetic models, viz. Lagergren, pseudo-first-order, second-order, pseudo-second-order and Elovich have been used to find the rate constants. Out of the four kinetic models tested, the pseudo-second-order model fitted the data well in the present case. It is found that when the pH of the wastewater is acidic the adsorption capacity is high. It is also seen that as the temperature of the wastewater increases, the capacity of adsorption also increases.

Removal of U(VI) from aqueous solution using phosphate functionalized bacterial cellulose as efficient adsorbent

2019 ◽  
Vol 107 (6) ◽  
pp. 459-467 ◽  
Author(s):  
Shuting Zhuang ◽  
Jianlong Wang
Keyword(s):  
Adsorption Capacity ◽  
Bacterial Cellulose ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Ph ◽  
Wide Ph Range ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Efficient Adsorbent

Abstract In this study, phosphate functionalized bacterial cellulose with micro-fibrous structure was prepared, characterized and applied for U(VI) adsorption. The successful grafting of phosphoric functional groups was proved by the FTIR spectra and EDS analysis (P~4.15 wt%), and the porous structure was confirmed by SEM and BET analyses. Furthermore, the effect of initial pH, contact time, initial concentration, and temperature were studied. The as-prepared adsorbent showed a high adsorption capacity at wide pH range (4.0–8.0) and its maximum adsorption capacity was calculated to be 50.65 mg/g. This endothermic adsorption process conformed to the pseudo second-order kinetic model and the Elovich kinetic models and the Langmuir isothermal models. According to the FTIR and XPS analysis, an adsorption mechanism was tentatively proposed, mainly due to the interaction between U(VI) and phosphoric groups.

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