The Potential of Wetlands as Treatment Systems for Organic Matter and Some Selected Metals (As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, and Zn): Case Study of Yitamot Wetland, Ethiopia

Table 1

Concentration of COD and metals in water sample of Yitamot wetland (mg/L).

Metal element	Metal concentration in sampling sites (mg/L)						US EPA 1986
	S1	S2	S3	S4	S5
COD	207.00^a	208.25^a	44.25^m	37.50^n	5.25^p		100.00
K	4.76^b	3.40^b	4.20^b	4.95^b	4.48^b
Na	14.91^c	10.44^c	10.75^c	13.88^c	12.15^c
Ca	46.26^d	27.32^d	50.18^d	32.50^d	52.98^d
Mg	4.20^e	2.48^e	4.51^e	5.96^e	5.90^e
Fe	0.81^f	1.03^f	23.82^h	1.00^f	0.41^f
Mn	0.11^g	0.05^g	0.17^i	0.02^g	nd
Cu	1.20^j	1.08^j	1.12^j	1.12^j	0.59^j		0.007
Zn	1.69^k	1.13^l	2.33^l	1.35^l	1.47^l
Pb	nd	nd	nd	nd	nd	nd	0.002
Cr	0.43^q	0.36^q	0.42^q	0.36^q	0.15^q		0.011
Cd	nd	nd	nd	nd	nd	nd	0.0007
As	0.40^r	0.41^r	0.44^r	0.38^r	0.38^r

nd = not detected; SE = standard error of mean. Values followed by the same letters in a raw are not significantly different at .