| Material | qm (mg/g) | Source |
| CuO nanostructures | 125 (Pb2+) | [36] |
| Rice husk | 133.34 (Cu2+) | [27] |
| Rice husk | 45.5 (Pb2+) | [15] |
| Prosopis juliflora | 201.08 (Cu2+) | [20] |
| Cymbopogon citrusstem | 1000 (Pb2+) | [37] |
| Wasted black tea | 166.67 (Cu2+) | [38] |
| F. natalensis fruits biochar | 1250 (Pb2+) | Current study |
| 161.29 (Cu2+) |