Table 4 Contamination indices and ranking of tailings impoundments located in the Aries river basin a
Enrichment factor (Ef) | |||||||
|---|---|---|---|---|---|---|---|
Impoundment | No (0 < Ef ≤ 1) | Minor (1 < Ef ≤ 3) | Moderate (3 < Ef ≤ 5) | Moderately severe (5 < Ef ≤ 10) | Severe (10 < Ef ≤ 25) | Very severe (25 < Ef ≤ 50) | Extremely severe (Ef > 50) |
Saliste | Ni < Cr | Cu | - | Zn(9.8) | Pb(22), Cd(23) | - | As(251) |
Gura Rosiei | Cr < Ni | Cu | Zn | Cd(7.7) | - | Pb(43) | As(255) |
Stefanca | Cr < Ni | - | Pb < Zn | Cd(5.4), As(9.6) | - | - | Cu(61) |
Sesei | Ni < Cr | - | Pb < Zn | Cd(9.1) | As(11) | - | Cu(76) |
Cutii | Ni < Cr | - | - | Zn(6.4), Cd(9.1), Cu(9.5) | - | - | Pb(59), As(715) |
Sartas | Cr | Ni | - | - | Cu(12), Zn(13) | - | Cd(34), Pb(73), As(860) |
Brazesti | Cr < Ni | - | - | Cu(6.9) | Zn(12) | Cd(41) | Pb(70), As(1100) |
Geoaccumulation index (I geo ) | |||||||
Impoundment | Practically unpolluted (I geo  < 0) | Unpolluted to moderately polluted (0 < I geo  ≤ 1) | Moderately polluted (1 < I geo  ≤ 2) | Moderately to heavily polluted (2 < I geo  ≤ 3) | Heavily polluted (3 < I geo  ≤ 4) | Heavily to extremely polluted (4 < I geo  ≤ 5) | Extremely polluted (I geo  > 5) |
Saliste | Cr < Ni < Cu | Zn | Pb(2.0), Cd(2.0) | - | - | - | As(5.5) |
Gura Rosiei | Cr < Ni < Cu < Zn < Cd | - | Pb(1.9) | - | - | As(4.5) | - |
Stefanca | Cr < Ni < Pb | Zn < Cd | As(1.3) | - | Cu(3.9) | - | - |
Sesei | Ni < Cr | Zn < Pb | Cd(1.5), As(1.7) | - | - | Cu(4.5) | - |
Cutii | Ni < Cr | Zn | Cd(1.4), Cu(1.5) | - | - | Pb(4.1) | As(7.8) |
Sartas | Cr < Ni |  | Cu(1.8), Zn(1.9) | - | Cd(3.4) | Pb(4.4) | As(8.0) |
Brazesti | Cr < Ni | Cu | Zn(1.6) | - | Cd(3.4) | Pb(4.2) | As(8.2) |
Contamination factor (C f ) | |||||||
Impoundment | Low (C f <1) | Moderate (1 < C f ≤3) | Considerable (3 < C f  ≤ 6) | Very high (C f >6) | |||
Saliste | Ni < Cr < Cu | Zn(2.6) | Pb(5.9) | Cd(6.1), As(67) | |||
Gura Rosiei | Cr < Ni < Cu < Zn < Cd | - | Pb(5.8) | As(34) | |||
Stefanca | Cr < Ni | Pb(1.3), Zn(1.4), Cd(2.0) | As(3.7) | Cu(23) | |||
Sesei | Ni < Cr | Zn(1.5), Pb(1.6) | Cd(4.1), As(4.9) | Cu(34) | |||
Cutii | Ni < Cr | Zn(2.9) | Cd(4.1), Cu(4.3) | Pb(26), As(321) | |||
Sartas | Cr < Ni | - | Cu(5.3), Zn(5.6) | Cd(15), Pb(32), As(384) | |||
Brazesti | Cr < Ni | Cu(2.6) | Zn(4.6) | Cd(16), Pb(28), As(437) | |||
Contamination degree (C d ) | |||||||
|  | Low (C d <8) | Moderate (8 < C d  ≤ 16) | Considerable (16 < C d  ≤ 32) | Very high (C d >32) | |||
Impoundment | - | - | - | Â | Stefanca (32), Gura Rosiei, (42), Sesei (46), Saliste (83), Cutii (360), Sartas (443), Brazesti (488) | ||