Polyacrylonitrile (PAN)-oxime-nano Fe2O3 was used as an adsorbent for the removal of fluoride from water. The influences of contact time, initial fluoride concentration, and adsorbent dosage were investigated by batch equilibrium studies. The rate of adsorption was rapid with equilibrium being attained after 100min. The Langmuir isotherm model was found to represent the measured adsorption data...

Several studies have reported various defluoridation capabilities of plant biomasses. The resultant variations in fluoride removal capacities are associated with the presence of different types of active functional groups in the respective biomasses. This study reports of the fluoride removal efficiencies of sisal leaf biomass in comparison. Comparison with other plant biomasses were made and h...

Fluoride in drinking water has a profound effect on teeth and bones. Up to a small level (1-1.5mg/L) this strengthens the enamel. Concentrations in the range of 1.5-4 mg/L result in dental fluorosis whereas with prolonged exposure at still higher fluoride concentrations (4-10mg/L) dental fluorosis progresses to skeletal fluorosis. High fluoride concentrations in groundwater, up to more than 30 ...

Excess fluoride in water causes health hazards to the natural environment. The removal of fluoride was attempted using natural materials such as red soil, charcoal, brick, fly-ash and serpentine. Each material was set up in a column for a known volume and the defluoridation capacities of these materials were studied with respect to time. According to the maximum defluoridation capacity these ma...

12 13 The removal of fluoride using red mud has been improved by acidifying red mud with 14 hydrochloric, nitric and sulphuric acid. This investigation shows that the removal of fluoride 15 using red mud is significantly improved if red mud is initially acidified. The acidification of 16 red mud causes sodalite and cancrinite phases to dissociate, confirmed by the release of 17 sodium and alumi...

Fluorides are found in the waste discharges from process streams in a number of industries. Significant amounts of fluoride come from the following industries: semiconductor, photovoltaic, glass manufacturers, electroplating, steel and aluminum, pesticides and fertilizer. The fluoride concentration in untreated effluent can vary over a large range, and the allowable level for discharge depends ...

Fluoride removal from water is being investigated using a natural adsorbent derived from bark of pinus kesiya. Batch studies were performed to study the effect of adsorbent dose, contact time, initial fluoride concentration and pH on the removal efficiency. The fluoride adsorption varies over wide range of pH and best in between 3 – 8. The rate of adsorption was rapid and maximum removal took p...

Fluoride removal from aqueous solutions using a-Al2O3 as an adsorbent was investigated through adsorption and electrokinetic studies, using two different initial fluoride concentrations relevant to fluoride contents in drinking water, namely 3 and 10 mg/L. Maximum fluoride removal was achieved between pH 5 and 6 at 258C. Adsorption at both pH 5 and 9 correlates to the Langmuir isotherm. The poi...