TY - JOUR
T1 - The Dynamic Adsorption Behaviour of Fluoride onto Surface-Tailored Zeolite
AU - Leswifi, Taile
AU - Onyango, Maurice S.
AU - Ochieng, Aoyi
AU - Otieno, Fred
PY - 2009
Y1 - 2009
N2 - Treatment of drinking water or wastewater containing health hazardous anionic species such as fluoride requires a robust and an effective technique. This can be achieved by the use of an appropriate sorption media in a fixed bed column. Recently, we developed a novel adsorption media: charge-reversed zeolite. This new sorption media was applied in removing fluoride, an inner-sphere complex forming ligand, from South African groundwater. Dynamic tests were performed using fixed bed column operated continuously or intermittently. Under continuous operation in which adsorbent type, flow rate and bed mass were variables, it was found that the performances of charge-reversed zeolite were higher than those of conventionally used sorption media such as activated alumina. Mechanistically, the uptake of fluoride is proposed to proceed by ion exchange and formation of inner-sphere complexes with the active sites, which are either protonated or neutral in nature. In attempts to delineate the controlling step(s) in the adsorption process, intermittent mode of operation was used in which the fingerprint of nonequilibrium adsorption as a result of probably intraparticle diffusion was confirmed.
AB - Treatment of drinking water or wastewater containing health hazardous anionic species such as fluoride requires a robust and an effective technique. This can be achieved by the use of an appropriate sorption media in a fixed bed column. Recently, we developed a novel adsorption media: charge-reversed zeolite. This new sorption media was applied in removing fluoride, an inner-sphere complex forming ligand, from South African groundwater. Dynamic tests were performed using fixed bed column operated continuously or intermittently. Under continuous operation in which adsorbent type, flow rate and bed mass were variables, it was found that the performances of charge-reversed zeolite were higher than those of conventionally used sorption media such as activated alumina. Mechanistically, the uptake of fluoride is proposed to proceed by ion exchange and formation of inner-sphere complexes with the active sites, which are either protonated or neutral in nature. In attempts to delineate the controlling step(s) in the adsorption process, intermittent mode of operation was used in which the fingerprint of nonequilibrium adsorption as a result of probably intraparticle diffusion was confirmed.
U2 - 10.4314/jcerp.v6i2.49353
DO - 10.4314/jcerp.v6i2.49353
M3 - Article
VL - 6
JO - Journal of Civil Engineering Research and Practice
JF - Journal of Civil Engineering Research and Practice
SN - 1729-5769
IS - 2
ER -