Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Table 2

Total elemental content of WD and ZR soils at depths of 0–20, 20–40, and 40–60 cm.

Metal		Soil sample						Critical values^a
	Depth	WD1	WD2	WD3	ZR1	ZR2	ZR3
	cm	mg kg^−1
Zn	0–20	60.1	65.7	74.7	61.7	69.3	66.2	70–400
	20–40	55.9	—	71.2	63.0	67.0	62.5
	40–60	60.1	—	—	63.1	69.7	—
Cd	0–20	1.8	1.9	2.0	2.5	4.0	2.8	3–8
	20–40	1.7	—	2.1	2.6	3.6	3.3
	40–60	1.6	—	—	2.4	4.3	—
Ni	0–20	43.9	42.6	46.3	36.5	40.7	39.1	100
	20–40	41.8	—	43.7	38.5	40.5	37.2
	40–60	45.2	—	—	46.4	40.7	—
Cu	0–20	18.8	19.1	20.7	18.0	26.7	18.9	60–125
	20–40	17.5	—	20.7	18.6	23.1	18.3
	40–60	18.8	—	—	18.3	23.6	—
Pb	0–20	25.7	25.1	23.8	31.2	29.0	27.1	100–400
	20–40	23.5	—	25.5	31.1	25.2	28.3
	40–60	23.7	—	—	30.0	28.6	—

aCited from Kabata-Pendias and Pendias, 1984 [15].