Table 5.
Efficiency rate of some chemical and biological strategies reported in the recent literature.
| Cr (VI) Initial Concentration | Treatment | Removal Efficiency (%) | References |
|---|---|---|---|
| 50 µg L−1 | Reduction by 1 mg L−1 of ferrous iron, | 92% | [47] |
| 300 µg L−1 | Fe (II)/Cr (VI) in a molar ratio of around 3 | Above 90% | [110] |
| 0.6 mg L−1 | Reduction by bentonite-supported nZVI | Above 90% | [112] |
| 50 mg L−1 | Electrocoagulation with Al-Al as pair of electrodes | 42% | [128] |
| 55.3 mg L−1 | Electrocoagulation with Fe-Fe as pair of electrodes | 91.7% | [131] |
| 5 mg L−1 | Electrocoagulation with Al alloy-Fe as pair of electrodes | 98.2% | [130] |
| 1 mg L−1 | Adsorption onto modified carbon nanotubes | 87% | [172] |
| 30 mg L−1 | Adsorption using biochar from Camellia oleifera seed shell | 99.99% | [124] |
| 0.5 mg L−1 | Adsorption onto pumice (VPum) and scoria (VSco) | 80% and 77%, respectively | [6] |
| 50 mg L−1 | Sulphur-based mixotrophic bio-reduction | 95.5% | [160] |
| 1000 µg L−1 | Bioreduction by indigenous microorganisms enhanced by yeast extract addition | 99.47% | [22] |
| 50 mg L−1 | Bioreduction by mixed bacterial consortium enhanced by phosphorus minerals addition | about 50% | [166] |
| 100 mg·L−1 | Biosorption using bacterial lawn deposited on membrane (seven bacterial strains tested) | from 5.32 to 99.87% | [142] |