| Control Sample | Single Chemical Treatments | Mixed-Chemical Treatments (Ni + Xanthates) | ||||||||
| Ni + PEX | Ni + SIPX | |||||||||
| Samples Code | CS | Ni | PEXa | PEXb | SIPXa | SIPXb | M1a | M1b | M2a | M2b |
| Dose (µg·g−1 soil) | 0 | 300 | 50 | 100 | 50 | 100 | 300 + 50 | 300 + 100 | 300 + 50 | 300 + 100 |