Adsorption Kinetics of Defluoridation Using Low-Cost Adsorbents

Jamode, A.V.; Sapkal, V. S.; Jamode, V. S.; Deshmukh, S. K.

doi:10.1260/026361704323151006

Cited by 14 publications

(8 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 The materials developed for this purpose include hydrated cement, 6 alumina containing bauxite, 7 activated carbon, 8 calcite, 9 fly ash, 10 red mud, 11 synthetic hydrous Fe(III) oxide, 12 Zr(IV) oxides, 13 lime and Al salts, 14,15 and La-impregnated silica gel. 16 Apart from these, adsorbents prepared from natural materials such as dry powder of holly oak, neem bark powder, lime stone, clay, concrete, jute, activated carbon, and leaf powder 17,18 have also been reported.…”

Section: Introductionmentioning

confidence: 99%

Comprehensive Understanding of the Kinetics and Mechanism of Fluoride Removal over a Potent Nanocrystalline Hydroxyapatite Surface

et al. 2017

View full text Add to dashboard Cite

Hydroxyapatite (HAp) was successfully synthesized from egg shells, a low cost and easily available biodegradable waste, by the precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy, Fourier transform infrared, and Brunauer–Emmett–Teller (BET) surface area analysis. The surface area of HAp was found to be 144 m 2 /g with a crystalline size of 9–99 nm from the BET and XRD data. The maximum fluoride removal efficiency within 1 h using 0.3 g of the synthesized adsorbent at pH 6 was 95%. The adsorption of fluoride followed second-order kinetics, indicating that chemisorptions are the rate-limiting step. The experimental data were well fitted with Langmuir and Freundlich isotherms, validating both monolayer and multilayer sorption during the fluoride adsorption onto the porous HAp. The positive adsorption of F – ions at the HAp interface can be attributed to ion exchange/ion pairing and H-bonding below the pH pzc of HAp (pH pzc = 8), and the negative adsorption can be attributed to the electrostatic repulsion between O – and F – ions at alkaline pH. Both physical and chemical adsorption phenomena were also evidenced from the molecular parking area data. The results of a batch experiment show that the HAp synthesized from egg shells can be used as an effective, low-cost adsorbent for fluoride removal from a contaminated aqueous solution as well as groundwater compared to other adsorbents.

show abstract

Section: Introductionmentioning

confidence: 99%

Comprehensive Understanding of the Kinetics and Mechanism of Fluoride Removal over a Potent Nanocrystalline Hydroxyapatite Surface

et al. 2017

View full text Add to dashboard Cite

show abstract

“…At low concentrations, it has beneficial effects on teeth; however excessive exposure to fluoride causes adverse health effects [4]. An intake of more than 6 mg fluoride per day will result in fluorosis [5]. Higher level of fluoride in ground water is a world-wide problem.…”

Section: Introductionmentioning

confidence: 99%

Adsorptive removal of fluoride from water using nanoscale aluminium oxide hydroxide (AlOOH)

Adeno¹,

Mulugeta²,

Zewge³

et al. 2014

Bull. Chem. Soc. Eth.

View full text Add to dashboard Cite

ABSTRACT. In this study the fluoride removal potential of nanoscale aluminium oxide hydroxide (nanoAlOOH) has been investigated. The material was produced using aluminium nitrate (Al (NO3)3 . 9H2O, 95%), and ammonium bicarbonate (NH4HCO3, 98%) and its density and mineralogy were investigated. A series of batch adsorption experiments were carried out to assess parameters that influence the adsorption process. The parameters considered were contact time and adsorbent dose, initial fluoride concentration, and pH. Results showed that most of the adsorption took place during the first 30 min; and equilibrium was reached at one hour contact time with an optimum adsorbent dose of 1. . The adsorption data were well fitted to the Langmuir isotherm model with a maximum adsorption capacity of 62.5 mg F -g -1 . The kinetic studies showed that the adsorption of fluoride by nano-AlOOH obeys a pseudo-second order rate equation. The intraparticle diffusion was not a rate-controlling step for the adsorption process. Thus, the overall study indicates that nano-AlOOH is an efficient defluoridating material.

show abstract

“…Based on the regression coefficient (R 2 ), the Langmuir model (R 2 = 0.9473) was found to be the better fit than the Freundlich (R 2 = 0.9284) and Temkin (R 2 = 0.9298) isotherm models. Similarly, various studies reported either Freundlich isotherm model [35,39] or Langmuir isotherm model [37,49] as the better fit to explain the biosorption behaviour of various adsorbents involved in the removal of fluoride ions. [10].…”

Section: Resultsmentioning

confidence: 99%