Removal of fluoride by thermally activated carbon prepared from neem (Azadirachta indica) and kikar (Acacia arabica) leaves.

The present investigation deals with fluoride removal from aqueous solution by thermally activated neem (Azadirachta indica) leaves carbon (ANC) and thermally activated kikar (Acacia arabica) leaves carbon (AKC) adsorbents. In this study neem leaves carbon and kikar leaves carbon prepared by heating the leaves at 400 degrees C in electric furnace was found to be useful for the removal of fluoride. The adsorbents of 0.3 mm and 1.0 mm sizes of neem and kikar leaves carbon was prepared by standard sieve. Batch experiments done to see the fluoride removal properties from synthetic solution of 5 ppm to study the influence of pH, adsorbent dose and contact time on adsorption efficiency The optimum pH was found to be 6 for both adsorbents. The optimum dose was found to be 0.5g/100 ml forANC (activated neem leaves carbon) and 0.7g/100 ml forAKC (activated kikar leaves carbon). The optimum time was found to be one hour for both the adsorbent. It was also found that adsorbent size of 0.3 mm was more efficient than the 1.0 mm size. The adsorption process obeyed Freundlich adsorption isotherm. The straight line of log (qe-q) vs time at ambient temperature indicated the validity of langergren equation consequently first order nature of the process involved in the present study. Results indicate that besides intraparticle diffusion there maybe other processes controlling the rate which may be operating simultaneously. All optimized conditions were applied for removal of fluoride from four natural water samples.

Urinary fluoride levels and prevalence of dental fluorosis in children of Jhajjar District, Haryana.

A study was conducted in the Jhajjar district of Haryana to assess the fluoride excretion in the population exposed to environmental fluoride and efforts were being made to correlate the results with dental fluorosis. The mean fluoride concentration in drinking water samples of Bahadurgarh, Beri, Jhajjar, Matanhail and Sahalawas blocks of Jhajjar district were 2.05 mg/L, 2.14 mg/L, 2.05 mg/L, 2.14 mg/L and 1.93 mg/L respectively. The mean urinary fluoride concentration was 1.58 mg/L in Bahadurgarh, 1.48 in Beri, 1.50 in Jhajjar, 1.51 in Matanhail and 1.56 in Sahalawas. The mean prevalence of fluorosis on the basis of stage of dental fluorosis was highest of yellowish brown type and on the basis of TSIF score, score 4 type fluorosis was highest in most of the blocks of Jhajjar district. The study revealed that more than 50% of the individuals were found to be affected with flurosis in this district.