scholarly journals Fluoride Adsorption by Pumice from Aqueous Solutions

2012 ◽  
Vol 9 (4) ◽  
pp. 1843-1853 ◽  
Author(s):  
Amir Hossein Mahvi ◽  
Behzad Heibati ◽  
Alireza Mesdaghinia ◽  
Ahmad Reza Yari
Keyword(s):  
Drinking Water ◽  
Aqueous Solutions ◽  
Fluoride Concentration ◽  
Freundlich Isotherm ◽  
Fluoride Removal ◽  
Maximum Sorption Capacity ◽  
Fluoride Adsorption ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
High Concentrations

Drinking water provides many vital elements for the human body, but the presence of some dissolved elements more than permissible concentration can endanger human health. Among the dissolved elements in drinking water, fluoride is noticeable, because both the very low or very high concentrations have adverse health impacts such as dental caries. Therefore, fluoride concentration should be kept in acceptable levels. In this study Pumice was used for fluoride removal. It was found that Fluoride sorption kinetic was fitted by pseudo-second-order model. The maximum sorption capacity of Pumice was found to be 13.51 mg/g at laboratory temperature (24°C). Maximum sorption study occurred at pH= 3. Results of Isotherm showed the fluoride sorption has been well fitted with Freundlich isotherm model. This study has demonstrated that Pumice can be used as effective adsorbents for fluoride removal from aqueous solutions. The adsorbent prepared in this study was cheap and efficient in removal of fluoride than other adsorbents.

Effect of Doped Iron on Fluoride Sorption by Calcined MgAlFe-CO3 Layered Double Hydroxides

2013 ◽  
Vol 681 ◽  
pp. 21-25
Author(s):  
Yu Bing Pu ◽  
Jia Rui Wang ◽  
Hong Zheng ◽  
Peng Cai ◽  
Si Yuan Wu
Keyword(s):  
Layered Double Hydroxides ◽  
Synthetic Wastewater ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Fluoride Removal ◽  
Maximum Sorption Capacity ◽  
Fluoride Adsorption ◽  
Maximum Sorption ◽  
Co Precipitation ◽  
Double Hydroxides

A series of MgAlFe-CO3 layered double hydroxides (LDHs) were successfully prepared by co-precipitation method. With synthetic wastewater, the effect of doped iron on fluoride sorption by calcined MgAlFe-CO3 layered double hydroxides (CLDH) under different pH and contact time conditions was investigated. The sorption isotherm data were fitted well to Langmuir isotherm at 25 °C. The maximum sorption capacity of fluoride on CLDH increases first and then decreases with the increase of Fe/Al molar ratio and attains maximum of 71.94 mg/g when Fe/Al molar ratio is 1:2, although doped iron is unfavorable to the regeneration of original layered structure for CLDH after fluoride adsorption. No aluminium in the solution after fluoride adsorption was detected when Fe/Al molar ratio is equal to or larger than 1:2. The results indicate that CLDH with proper Fe/Al molar ratio is a promising candidate as an adsorbent material for fluoride removal from aqueous solutions.

Adsorption of CuCl2 on Mg-Al HTlc: Effect of EDTA and Addition Sequences

2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu
Keyword(s):  
Aqueous Solutions ◽  
Sorption Capacity ◽  
Contact Time ◽  
Room Temperature ◽  
Copper Ions ◽  
Sorption Process ◽  
Langmuir Model ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.

scholarly journals Eggshell-Derived Nanohydroxyapatite Adsorbent for Defluoridation of Drinking Water from Bofo of Ethiopia

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Kifle Workeneh ◽  
Enyew Amare Zereffa ◽  
Toshome Abdo Segne ◽  
Rajalakshmanan Eswaramoorthy
Keyword(s):  
Removal Efficiency ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Alternative Source ◽  
Fluoride Adsorption ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Eggshell Waste

Fluoride has become a notable toxicological environmental hazard worldwide because it is often found in groundwater. In the present study, hydroxyapatite adsorbent was synthesized from eggshell waste to remove fluoride from aqueous solution. XRD, FT-IR, and TGA techniques were used to characterize the prepared adsorbent. Batch adsorption studies were performed to examine the adsorption capacity of hydroxyapatite such as the effect of the initial pH of the solution, contact time, adsorbent dose, and initial fluoride concentration. The fluoride ion-selective electrode was used to determine the fluoride removal efficiency. 98.8% of fluoride was removed at pH 3.0, but at pH ~7.0, 85% of fluoride was removed; it shows that the fluoride adsorption is pH dependent. The adsorption isotherm studies (Langmuir and Freundlich models) and the experimental results for the removal of fluoride showed that the Langmuir model was more favorable and the reaction followed pseudo-second-order kinetics. In real water samples, the prepared hydroxyapatite derived from eggshell exhibited 81% removal efficiency. Our results indicate that eggshell waste-derived hydroxyapatite may be an alternative source for defluoridation in developing countries.

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.

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.

scholarly journals Studies on chromium(III) removal from aqueous solutions by sorption on Sphagnum moss peat

2009 ◽  
Vol 74 (8-9) ◽  
pp. 953-964 ◽  
Author(s):  
Catalin Balan ◽  
Doina Bilba ◽  
Matei Macoveanu
Keyword(s):  
Aqueous Solutions ◽  
Metal Ion ◽  
Sorption Isotherms ◽  
Second Order ◽  
Ion Concentration ◽  
Sphagnum Moss ◽  
Order Kinetic ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

Batch sorption experiments were performed for the removal of chromium(III) ions from aqueous solutions using Romanian Sphagnum moss peat (untreated and treated with NaCl solution) as sorbent. In order to establish the best conditions for the sorption of chromium(III), the influence of initial pH, contact time, peat dose and metal ion concentration was investigated. The Freundlich, Langmuir and Dubinin-Radushkevich models were applied to describe the sorption isotherms and to calculate its constants. The experimental data fitted well to the Langmuir model with a maximum sorption capacity of 18.6 mg Cr(III)/g of peat. The mean free energy of sorption suggests that the binding of Cr(III) on peat occurred through an ion exchange mechanism. The kinetic data evaluated by pseudo-first order and pseudo-second order kinetic models showed that the sorption of chromium onto the peat followed a pseudo-second order rate equation. The chromium(III) could be easily eluted from the loaded peat using 0.10 M HCl and the peat may be reused in several sorption/ desorption cycles. The experimental results indicated the potential of Sphagnum moss peat for removal of Cr(III) from wastewaters.

scholarly journals Removal of Fluoride from Drinking Water Using Modified Immobilized Activated Alumina

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Aneeza Rafique ◽  
M. Ali Awan ◽  
Ayesha Wasti ◽  
Ishtiaq A. Qazi ◽  
Muhammad Arshad
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Activated Charcoal ◽  
Contact Time ◽  
Sol Gel ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Activated Alumina ◽  
Fluoride Adsorption

The study describes the removal of fluoride from drinking water using modified immobilized activated alumina (MIAA) prepared by sol-gel method. The modification was done by adding a specific amount of alum during the sol formation step. The fluoride removal efficiency of MIAA was 1.35 times higher as compared to normal immobilized activated alumina. A batch adsorption study was performed as a function of adsorbent dose, contact time, stirring rate, and initial fluoride concentration. More than 90% removal of fluoride was achieved within 60 minutes of contact time. The adsorption potential of MIAA was compared with activated charcoal which showed that the removal efficiency was about 10% more than the activated charcoal. Both the Langmuir and Freundlich adsorption isotherms fitted well for the fluoride adsorption on MIAA with the regression coefficientR2of 0.99 and 0.98, respectively. MIAA can both be regenerated thermally and chemically. Adsorption experiments using MIAA were employed on real drinking water samples from a fluoride affected area. The study showed that modified immobilized activated alumina is an effective adsorbent for fluoride removal.

scholarly journals Eggshell Powder as an Adsorbent for Removal of Fluoride from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

2012 ◽  
Vol 9 (3) ◽  
pp. 1457-1480 ◽  
Author(s):  
R. Bhaumik ◽  
N. K. Mondal ◽  
B. Das ◽  
P. Roy ◽  
K. C. Pal ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Fluoride Removal ◽  
Contaminated Water ◽  
Fluoride Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Studies ◽  
Maximum Removal

A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Eawas found to be 45.98 kJmol-1by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.

scholarly journals Biosorption of Fluoride from Synthetic and Ground Water Using Chlorella vulgaris Immobilized in Calcium Alginate Beads in an Upflow Packed Bed Column

2017 ◽  
Vol 61 (3) ◽  
pp. 188 ◽  
Author(s):  
Poornima G. Hiremath ◽  
Thomas Theodore
Keyword(s):  
Experimental Data ◽  
Ground Water ◽  
Chlorella Vulgaris ◽  
Water Samples ◽  
Packed Column ◽  
Fluoride Concentration ◽  
Fixed Bed ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Fluoride Adsorption

The potential of immobilized Chlorella vulgaris to remove fluoride from synthetic and real ground water samples in a fixed bed was investigated. The effect of important kinetic parameters including column bed height, feed flow rate and influent fluoride concentration of solution on fluoride removal was studied. Thomas, Yoon-Nelson, and BDST models were used to analyze the experimental data and understand the influence on biosorption performance. The models’ predictions were in good agreement with the experimental data for all the process parameters studied, indicating that the models were suitable for fixed-bed column design. Fluoride adsorption was reversible. Desorption of fluoride ions was accomplished by pumping 0.1 N HCl solution. The reusability of adsorbent was studied by subjecting column to repeated cycles of fluoride adsorption and desorption. The suitability of immobilized C. vulgaris adsorbent for fluoride removal from ground water samples of Pavagada taluk, Tumakuru district was studied in the packed column.

Sign in / Sign up

Export Citation Format

Share Document