Removal of Fluoride from Aqueous Solutions by Adsorption using a Siliceous Mineral of a Kenyan Origin
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Date
2013-04-01
Authors
Ambusso, W.
Muthakia, G. K.
Onindo, C.O.
Wambu, E.W.
Journal Title
Journal ISSN
Volume Title
Publisher
WILEY‐VCH Verlag
Abstract
The problem of high fluoride in water sources in Africa and the rest of the developing world has exacerbated in the latest past due to increasing shortage of water. More people are being exposed to high water fluoride resulting in elevated levels of fluorosis in the societies. Fluoride (F) adsorption from solutions using a siliceous mineral from Kenya (M1) was studied on batch basis and results verified on high fluoride water using fixed-bed column experiments. About100% batch F adsorption wasachieved at 200mg/L
F concentration, 0.5g/mL adsorbent dosage, 303–333K, and pH 3.4
0.2. Based on Giles classifications, F adsorption isotherm was found to be an H3 type isotherm. The equilibrium data was correlated to Freundlich and Langmuir models and the maximum Langmuir adsorption capacity was found to be 12.4mg/g. Column experiments were conducted for different fluoride concentrations, bed depths, and flow rates. The F breakthrough curves were analyzed using the Thomas model and efficient F adsorption
was found to occur at low flow rates and low influent concentrations. The Thomas F adsorption capacity (11.7mg/g) was consistent with the Langmuir isotherm capacity showing that M1 could be applied as an inexpensive medium for water defluoridation
Description
DOI: 10.1002/clen.201100171
Keywords
Batch adsorption,, Breakthrough curve,, Equilibrium isotherm,, Fluorosis,, Water quality.