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

Table 3

The average seasonal physico- and hydrochemical parameters of Tengeru and Maji ya Chai River water.

Season	pH	(°C)	Ca^2+	Mg^2+	Na^+	K^+			Cl^-		TDS	EC (µS/cm)
Tengeru River
Wet
Min.	7.12	15.00	0.48	1.21	0.62	0.33	10.14	7.27	2.50	0.00	37.00	72
Max.	7.58	19	8.20	12.18	3.62	1.94	42.46	39.13	24.99	10.00	260.00	518
Av.	7.34 ± 0.13	17.53 ± 1.12	2.35 ± 2.19	3.76 ± 1.21	1.48 ± 0.84	0.79 ± 0.79	17.74 ± 7.82	16.29 ± 9.24	13.79 ± 5.70	1.20 ± 2.28	110.81 ± 52.62	221.52 ± 105.06
Dry
Min.	7.23	14.00	8.00	1.21	2.56	0.79	19.14	20.15	12.50	0.00	42.00	83.00
Max.	8.59	21.00	24.00	15.78	8.27	2.56	73.22	62.44	137.00	25.00	243.00	474.00
Av.	7.90 ± 0.36	18.04 ± 1.80	12.95 ± 4.41	5.88 ± 4.10	4.25 ± 1.51	1.32 ± 0.47	39.99 ± 16.17	33.95 ± 11.44	42.71 ± 25.96	7.89 ± 8.27	131.43 ± 50.75	262.33 ± 100.41
Maji ya Chai River
Wet
Min.	7.37	17.00	0.49	1.21	1.52	0.22	6.57	6.27	0.00	5.00	395.00	791.00
Max.	8.60	19.48	2.43	6.08	4.56	0.67	32.86	18.82	16.00	39.99	594.00	1187.00
Av.	8.03 ± 0.57	18.27 ± 0.82	1.50 ± 0.63	3.75 ± 1.58	2.95 ± 0.91	0.43 ± 0.13	20.46 ± 8.61	12.21 ± 3.77	7.63 ± 6.38	18.56 ± 13.68	477.14 ± 77.17	954.86 ± 153.96
Dry
Min.	7.91	17.37	10.00	2.43	3.77	1.10	3.35	31.14	35.00	11.00	448	896
Max.	9.60	21	14.00	7.28	5.28	1.53	4.69	43.59	87.50	30.00	861	1722
Av.	8.57 ± 0.52	19.95 ± 1.35	11.25 ± 1.50	3.81 ± 1.63	4.33 ± 0.52	1.26 ± 0.15	3.85 ± 0.47	35.81 ± 4.32	58.23 ± 16.44	23.98 ± 7.24	591.86 ± 173.82	1183.43 ± 347.54

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