Abstract
A series of sorption of fluoride on calcined magnesite are obtained from thermostatic pH-chemostat and jar test experiments. The fluoride removal is observed not to start instantly, as normal, but after a lag time of up to ½ an hour of contact time. A model for sorption kinetics is developed, based on first-order reaction with respect to the concentration of fluoride. The rate constant is directly proportional to the dosage. The model takes into accounts the lag time observed. The kinetical model can be described for any given dosage and initial fluoride concentration in the water. The reaction rate parameter, K, varies however slightly for different initial concentrations of fluoride in the water and different dosage of calcined magnesia. These relationships are described separately by two linear equations. It is discussed that the observed lag time is due to the fact that magnesia cannot remove fluoride without hydrolysis, and it is probably this hydrolysis which constraint the start of the removal.
| Original language | English |
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| Title of host publication | Proceedings of the 2nd International Workshop on Fluorosis Prevention and Defluoridation of Water |
| Editors | Eli Dahi, Joan Maj Nielsen |
| Number of pages | 7 |
| Publication date | 1997 |
| Pages | 83-89 |
| Publication status | Published - 1997 |
| Event | 2nd Workshop on Fluorosis and Defluoridation - Nazreth, Ethiopia Duration: 19 Nov 1997 → 25 Nov 1997 |
Conference
| Conference | 2nd Workshop on Fluorosis and Defluoridation |
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| Country/Territory | Ethiopia |
| City | Nazreth |
| Period | 19/11/1997 → 25/11/1997 |