Defluoridation with Locally Produced Thai Bone Char

Figure 2

Comparisons of the mass of fluoride sorbed per unit mass of Thai and Indian bone char with the increasing concentrations of (a) chloride, (b) nitrate, (c) sulfate, and (d) fluoride in the groundwater samples.

(a) Chloride: the water samples (from left) are the synthetic solution, and sites 1, 2, 3, 5, 4, and 6 are in Table 1, shown in increasing concentrations

(b) Nitrate: the water samples (from left) are the synthetic solution, and sites 2, 1, 4, 5, 3, and 6 are in Table 1, shown in increasing concentrations

(c) Sulfate: the water samples (from left) are the synthetic solution, and sites 6, 1, 2, 4, 5, and 3 are in Table 1, shown in increasing concentration

(d) Fluoride: the water samples (from left) are the synthetic solution, and sites 4, 6, 2, 5, 1, and 3 are in Table 1, shown in increasing concentration