A low cost domestic defluoridator has been developed by the National Water Supply & Drainage Board of Sri Lanka to remove excess fluoride in drinking water to avoid endemic Fluorosis. Broken pieces of freshly burnt bricks are used as filter media in these units. A kinetic model for fluoride uptake in the filter with broken bricks as defluoridating agent is considered and the model parameters are estimated using experimental data. Data concerning the uptake of fluoride on broken brick pieces are obtained from water in batch in the defluoridator. The reaction rate parameter, k, and the capacity parameter fm are estimated and the model fits the collected data satisfactorily. fm is estimated to 0.10 mg/g and k which is a function of initial concentration varies between 0.001 and 0.0005 L/ (mg.ho.5) for low and high initial concentration. Broken bricks could be used as filter media for concentration of fluoride in raw water around 2 mg/l.
*Original article in pdf online at http://fluoridealert.org/wp-content/uploads/wijesundara-2004.pdf