Water Science & Technology: Water Supply Vol 1 No 1 pp 81–88 © IWA Publishing 2001
Removal of ammonia by natural clay minerals
using fixed and fluidised bed column reactors
MS Çelik*, B Özdemir**, M Turan***, I Koyuncu****, G Atesok***** and HZ Sarikaya******
*
Istanbul Technical University, Mining Engineering Department,
Ayazaga 80626 Istanbul-Turkey
**
Istanbul Technical University, Mining Engineering Department,
Ayazaga 80626 Istanbul-Turkey
***
Istanbul Technical University, Environmental Engineering Dept.,
Ayazaga Istanbul-Turkey
****
Istanbul Technical University, Environmental Engineering Dept.,
Ayazaga Istanbul-Turkey
*****
Istanbul Technical University, Mining Engineering Department,
Ayazaga 80626 Istanbul-Turkey
******
Istanbul Technical University, Environmental Engineering Dept.,
Ayazaga Istanbul-Turkey
ABSTRACT
A series of fixed and fluidised bed ion exchange column runs were conducted
to identify the ability of natural clay minerals, sepiolite and
clinoptilolite, to remove ammonia from a contaminated drinking water
reservoir. Ion exchange column tests using both fixed and fluidised bed
were initially carried out with synthetic water composed of
NH4Cl. Breakthrough curves as a function of flow rate,
particle size, and initial ammonia concentration reveal that sepiolite
does not have as high ion exchange capacity as clinoptilolite but
maintains a steady adsorption up to higher bed volumes. The adsorption
capacity was modified by using regeneration cycles at both acidic and
alkaline pH. Furthermore, fluidised bed runs with clinoptilolite utilising
water and air as fluidiser resulted in inferior results compared to those
of fixed bed runs. This was respectively ascribed to the presence of
ammonia in the circulating water and competition of exchangeable ions
released in water and the ability of air to adsorb nitrogen. Tests conducted with natural raw water contaminated with sewage indicated that
clinoptilolite adsorbs ammonia the same as the synthetic water. Regenerated
clinoptilolite is capable of removing ammonia from both synthetic and
actual raw water at a much higher rate than the untreated clinoptilolite.
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