Fluoride Variations in Rivers on the Slopes of Mount Meru in Tanzania

Table 2

The average seasonal physico- and hydrochemical parameters of Temi and Nduruma River water.

Season	pH	(°C)	Ca^2+	Mg^2+	Na^+	K^+			Cl^-		TDS	EC (µS/cm)
Temi River
Wet
Min.	7.32	14.95	2	2.43	0.76	0.21	13.71	6.18	0	0	88	176
Max.	8.07	20	114	23.085	43.33	12.23	212.71	352.18	77.475975	6.18	400	802
Av.	7.70 ± 0.26	17.01 ± 1.80	22.5 ± 34.17	7.96 ± 7.20	7.96 ± 12.98	2.42 ± 3.66	57.08 ± 64.34	69.58 ± 105.51	33.28 ± 22.69	4.38 ± 6.67	169.83 ± 127.50	339.75 ± 255.38
Dry
Min.	7.37	14.95	3.66	2.16	1.38	0.41	9.78	11.40	0.11	0.06	41	82
Max.	9.01	25	40.51	21.84	15.30	4.58	117.91	126.00	13	2.38	698	1396
Av.	8.31 ± 0.67	20.44 ± 2.44	23.97 ± 8.72	12.60 ± 6.09	9.05 ± 3.29	2.68 ± 0.99	67.89 ± 26.17	74.74 ± 27.13	4.58 ± 8.21	0.92 ± 0.57	245.42 ± 240.99	491.5 ± 481.11
Nduruma River
Wet
Min.	7.63	12.21	2.00	1.21	0.70	0.22	6.57	6.25	15.00	0.00	71	142
Max.	9.04	20.48	10.00	10.86	3.78	1.11	43.57	31.26	44.99	9.10	108	217
Av.	7.98 ± 0.37	17.20 ± 2.24	4.57 ± 2.51	5.40 ± 3.19	1.74 ± 0.95	0.54 ± 0.26	21.25 ± 10.94	15.35 ± 8.41	28.82 ± 8.70	1.28 ± 2.66	90.67 ± 12.48	179.33 ± 26.73
Dry
Min.	7.40	12.01	1.21	5.00	0.48	0.14	26.92	3.81	45.00	1.35	81	88
Max.	9.90	24.32	9.22	38.00	3.61	1.06	92.20	28.92	122.50	23.49	154	308
Av.	8.22 ± 0.72	19.00 ± 3.25	4.63 ± 2.62	20.00 ± 10.04	1.95 ± 0.95	0.58 ± 0.28	59.00 ± 15.00	15.28 ± 7.70	73.12 ± 21.18	3.96 ± 6.18	117.83 ± 24.14	223.42 ± 64.31

Note. All concentration measurements are in mg/l. Min.: minimum; Max.: maximum; Av.: average.