Assessment of metallic trace elements mobility from mine tailing and soils around abandoned Pb mine site in North East Morocco

Figures & data

Figure 1. General setting of Zeïda mining area and the sampling stations.

Table 1. Physico-Chemical properties and total content of metallic trace elements of studied mine tailing and soils.

		Tailing (S1)				Soils (S2 + S3 + S4)
	Samples	Max	Min	Range	Average	Max	Min	Range	Average
Physico-Chemical properties	CO (g kg^−1)	0.72	0.62	0.10	0.67	5.48	1.62	3.86	4.19
	NT (g kg^−1)	0.10	0.05	0.05	0.08	0.58	0.04	0.54	0.38
	CI (g kg^−1)	2.70	1.53	1.17	2.11	3.67	1.53	2.14	2.38
	MO (g kg^−1)	1.00	0.84	0.16	0.91	9.19	2.55	6.64	6.97
	CaCO3 (g kg^−1)	23.46	11.83	11.63	17.36	31.95	11.56	20.39	20.28
	salinity (dS m^−1)	0.08	0.07	0.01	0.08	0.05	0.02	0.03	0.03
	pH	8.75	8.35	0.40	8.52	8.33	7.19	1.14	7.89
	EC (μs/cm)	164.90	143.60	21.30	157.40	197.97	82.03	115.94	129.76
	CEC cmol Kg^−1	3.19	1.07	2.12	2.10	5.55	0.39	5.16	2.81
	silt (%)	60.53	54.32	6.21	57.53	23.03	8.62	14.41	19.46
	sand (%)	10.34	9.74	0.60	10.03	74.97	39.00	35.97	52.27
	clay (%)	36.12	29.13	6.99	32.59	30.22	6.01	24.21	20.04
Total concentration (mg kg^−1)	Pb	10703.21	5335.61	5367.60	8319.19	33.02	11.65	21.37	18.77
	As	96.53	58.21	38.32	77.80	3.24	1.68	1.56	2.61
	Cd	0.33	0.26	0.07	0.30	0.07	0.03	0.04	0.05
	Cu	112.29	95.82	16.47	106.28	8.82	5.58	3.24	7.00
	Ni	11.11	9.12	1.99	10.23	20.99	6.48	14.51	11.10
	Cr	17.25	12.47	4.78	15.45	16.69	10.52	6.17	14.12
	Zn	150.31	103.77	46.54	132.01	74.46	27.17	47.29	45.14
Potential leaching risk (mg kg^−1)	Pb	8293.89	4151.72	4142.17	6440.66	28.78	10.22	18.56	16.09
	Cd	0.22	0.10	0.12	0.16	0.05	0.02	0.03	0.04
	Cu	88.50	76.25	12.25	84.35	2.31	0.76	1.55	1.49
	Ni	6.86	5.79	1.07	6.49	17.41	3.98	13.43	8.03
	Cr	4.96	4.79	0.17	4.87	13.56	9.54	4.02	11.64
	Zn	97.50	53.71	43.79	81.09	66.46	15.05	51.41	37.82

CO: Organic Carbon, MO: Organic Matter, CI: Inorganic Carbon, TN: Total Nitrogen, CEC: Cation Exchange Capacity, CaCO₃: Carbonate Content, EC: Conductivity.

Figure 2. Patterns of X-ray diffraction (a) and mineralogical composition of studied mine tailing and soils (b).

Figure 3. Percentage distribution of M.T.Es in the chemical fractions sequentially extracted from studied mine tailing and soils.

Table 2. Variations in ecological indices of metallic trace elements at the mine tailing and soils.

		Tailing (S1)				Soils (S2 + S3 + S4)
Ecological risk indices	Metallic trace elements	Max	Min	Range	Average	Max	Min	Range	Average
Contamination factor	Pb	3313.69	2516.80	796.89	2997.72	11.71	4.39	7.32	6.97
	As	6.76	4.97	1.79	5.94	4.37	0.90	3.47	2.12
	Cd	1.42	0.94	0.48	1.23	1.26	0.87	0.39	1.11
	Cu	1.38	0.73	0.65	1.04	1.69	0.71	0.98	1.05
	Ni	6.99	5.17	1.82	6.24	0.48	0.34	0.14	0.41
	Cr	1.10	0.87	0.23	1.01	0.23	0.10	0.13	0.18
	Zn	18.85	11.13	7.72	14.50	0.63	0.32	0.31	0.48
Geo-accumulation index	Pb	11.11	10.71	0.40	10.95	2.97	1.55	1.42	2.16
	As	3.65	2.89	0.76	3.24	−1.25	−2.22	0.98	−1.65
	Cd	−0.45	−0.79	0.34	−0.58	−2.68	−3.91	1.22	−3.12
	Cu	2.22	1.79	0.43	2.04	−1.65	−2.15	0.50	−1.90
	Ni	−0.12	−1.03	0.91	−0.58	0.17	−1.07	1.25	−0.55
	Cr	−0.08	−0.67	0.59	−0.31	−0.25	−0.79	0.55	−0.44
	Zn	2.17	1.73	0.45	1.97	1.54	−0.74	2.28	0.34

Figure 4. Multivariate statistical analyses of M.T.Es and physico-chemical properties, in studied mine tailing and soils: Pearson’s correlation matrix (a) and principal component analyses (PCA) (b).

Figure 5. Heatmap of the total M.T.Es contents, their fractionations, their leaching risk potentials and the physico-chemical properties in mine tailing and soils.