Table 1.

Mean heavy metal concentrations, pH, and conductivity in mining residues samples.

Mining areas	Mining residues content
	Heavy metals content g·Kg−1					pH	Conductivity (mS·cm−1)
	Pb	Cu	Zn	Cd	Cr
Kettara	0.028 ± 0.007	2.942 ± 0.134	0.685 ± 0.092	ND	0.017 ± 0.002	2.20	10.28
Bir Nhass	1.407 ± 0.341	0.095 ± 0.024	9.989 ± 1.223	0.075 ± 0.011	0.031 ± 0.005	6.52	2.21
Sidi Bouatman	10.189 ± 3.580	0.102 ± 0.029	18.870 ± 5.733	0.044 ± 0.017	0.035 ± 0.005	7.42	2.08
Arbar plant	1.619 ± 0.432	1.243 ± 0.079	14.434 ± 0.928	0.070 ± 0.007	0.006 ± 0.001	7.17	2.27
Tenfit mine	0.098 ± 0.002	0.498 ± 0.068	2.093 ± 1.020	ND	0.014 ± 0.001	7.52	1.46

^*ND: not detected.