Hydrogeochemistry of Fluorine in Groundwater in Humid Mountainous Areas: A Case Study at Xingguo County, Southern China

Table 2

Summary of Ca²⁺, , pH, TDS, and F⁻ in groundwater of different groundwater subsystems.

Groundwater subsystem	Number of samples	Ca^2+ (mg/L)		(mg/L)		pH		TDS (mg/L)		F^− (mg/L)
		Range	Average	Range	Average	Range	Average	Range	Average	Range	Average
Suishui River III2-1-2	79	1–32	9.2	3.05–73.22	24.6	5.19–8.48	6.3	5–125	41.7	0.02–1.32	0.19
Jianshui River III3-1-1	36	3–46	15.4	6.10–67.12	26.1	5.60–7.32	6.5	15–155	59.5	0.02–0.51	0.15
Shuicha River III4-1-1	4	1–5	2.5	6.10–12.20	8.4	5.37–6.83	6.2	8–19	14.3	0.02–0.09	0.06
Wushu River III5-1-1	11	2–54	15.2	6.10–140.35	34.4	5.85–7.42	6.7	16–194	64.7	0.01–0.28	0.08