Development of a household method for treatment of highly fluoridated water using processed eggshell

Abstract

High intake of fluoride generates a clinical entity called fluorosis. The World Health Organization has recommended a limit for water consumption of 1.5 mg/l. When this limit is exceeded water needs remediation. Eggshell is a calcium rich waste that could be used as a resource for the reduction of water fluoride because the fluoride reacts with calcium to form calcium fluoride. The objective of this work was to develop an eco-friendly method for the elimination of fluoride from water. Upon investigating different variables of this method the following was established: 1. Incineration of eggshell increases 5.6 times fluoride uptake. 2. Time required to complete 50% of the uptake process is 0.52±0.12 min. 3. Fluoride uptake increases significantly as the size of particles decreased: thick (1.72±0.55), thin (1.59±0.30) and ultra thin (2.37±0.35) (ANOVA, LSD test p<0.05). 4. The remediated water is neutralized using compressed CO2 and CO2 from air. 5. The organoleptic characteristics were determined and, remediated water was: colorless, tasteless and odorless. No differences were found when comparing the remediated solution with tap water of Rosario, Santa Fe, Argentina. In conclusion, the method developed in this work is suitable for the remediation of fluoride in water on a laboratory setting; further studies need to be done to apply this methodology at a household level.