TABLE 4.
Adsorption capacity of heavy metals by using different sorbents.
| Biosorbent | Metal | pH | T, (°C) | Initial concentration, (mg L–1) | Adsorption capacity mg g-1 | References |
|---|---|---|---|---|---|---|
| Arca shell | Pb(II) | 1–7 | 25 ± 2 | 10–500 | NA | Dahiya et al. (2008) |
| Cu(II) | ||||||
| Ni(II) | ||||||
| Co(II) | ||||||
| Cs(I) | ||||||
| Cactus leaves | Cr(VI) | 1–10 | 30 | 20–1000 | NA | Yuncu et al. (2006) |
| Crab shell | Cu(II) | 3.5–6 | NA | 500–2000 | 243.9 | Vijayaraghavan et al. (2006) |
| Co(II) | 322.6 | |||||
| Exhausted coffee | Cu(II) | 5.2 | 20 ± 1 | 5–300 | 11.6 | Eseudero et al. (2008) |
| Ni(II) | 7.25 | |||||
| Grape stalk | Cu(II) | 5.2 | 20 ± 1 | 5–300 | 42.92 | |
| Ni(II) | 38.31 | |||||
| Maize bran | Cr(VI) | 1.4–8 | 20–40 | 20–300 | NA | Hasan et al. (2008) |
| Treated sour orange residue | Cu(II) | 4.5 | 28 | 300 | 52.08 | Khormaei et al. (2007) |
| Orange peel | Pb(II) | 1–7 | NA | 103.5–2070 | NA | Xuan et al. (2006) |
| Palm kernel fiber | Pb(II) | 3–8 | 36 ± 3 | 120 | NA | Ho and Ofomaja (2006) |
| Tea waste | Cr(VI) | 2–5 | 25–60 | 50–400 | 54.65 | Malkoc and Nuhoglu (2007) |
| Ulva lactuca | Pb(II) | 2–8 | 20–50 | 10–400 | 34.7 | Sari and Tuzen (2008) |
| Cd(II) | 29.2 | |||||
| Dairy manure biochar | Cu(II) | NA | NA | 63.53–317.7 | 48.4–54.4 | Xu et al. (2013) |
| Zn(II) | 65.38–326.9 | 31.6–32.8 | ||||
| Cd(II) | 112.41–562.05 | 31.9–51.4 | ||||
| Crop straw biochar | Cu(II) | NA | 25 ± 1 | 773.36 | NA | Tong and Xu (2013) |