Table 1 Upper concentration limits for heavy metals in water according to WHO and USEPA:
From: Microbial bioremediation as a tool for the removal of heavy metals
Metal | Symbol | WHO (µg L−1) | USEPA (µg L−1) |
|---|---|---|---|
Cadmium | Cd | 3 | 5 |
Lead | Pb | 10 | 15 |
Chromium | Cr | 50 | 100 |
Mercury | Hg | 1 | 2 |
Zinc | Zn | 1000 | 1000 |
Copper | Cu | 2000 | 1300 |
Nickel | Ni | 20 | – |
Aluminum | Al | 200 | 200 |
Manganese | Mn | 100 | 50 |
Iron | Fe | 300 | 300 |
Arsenic | As | 10 | 10 |