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The present investigation reports the assessment of hydrochemical/geochemical processes controlling the concentration of fluoride in groundwater of a village in India (Boden block, Orissa). Boden block is one of the severely affected fluoride-contaminated areas in the state of Orissa (India). The sampling and subsequent analysis of water samples of the study area was carried out following standard prescribed methods. The results of the analysis indicate that 36.60% groundwater F(-) concentration exceeds the limit prescribed by the World Health Organization for drinking water. The rock interaction with groundwater containing high concentration of HCO(3)(-) and Na(+) at a higher pH value of the medium could be one of the important reasons for the release of F(-) from the aquatic matrix into groundwater. Geochemical classification of groundwater based on Chadha rectangular diagram shows that most of the groundwater samples having fluoride concentration more than 1.5 mg L(-1) belongs to the Na-K-HCO(3) type. The saturation index values evaluated for the groundwater of the study area indicated that it is oversaturated with respect to calcite, whereas the same is undersaturated with respect to fluorite content. The deficiency of calcium ion concentration in the groundwater from calcite precipitation favors fluorite dissolution leading to excess of fluoride concentration. The risk index was calculated as a function of fluoride level in drinking water and morbidity of fluorosis categorizes high risk for villages of Amera and Karlakote panchayat of Boden block.

Abstract: A novel zirconium(IV)-ethylenediamine (ZrEDA) hybrid material was prepared by mixing aqueous solution of zirconium oxychloride (0.1M) and aqueous solution of ethylenediamine (0.1M) following an environmental friendly sol–gel method. The material was characterized by FTIR, XRD and SEM combined with energy dispersive spectrum technique. The hybrid material was tested for removal of fluoride with variation of solution parameters. The extent of fluoride removal was more than 99% and fluoride adsorption equilibrium was attained in a 14min time period. The adsorption follows a pseudo second order kinetics with theoretical adsorption capacity (q e,cal) and experimental adsorption capacity (q e,exp) close to each other. The value of thermodynamic parameter ΔH indicated an endothermic adsorption process. A negative value of ΔG shows the feasibility and spontaneity of material-anion interaction. The adsorbed fluoride could easily be desorbed from the material by using 0.1M NaOH solution. Further, the regenerated material was tested up to 10th consecutive cycles of operation without significance loss of adsorption efficiency. [Copyright &y& Elsevier]