Table 1.
Results of metal removal from sludge suspension at pH 10.7, 2 wt.% sludge suspension, 10 mg of nanoadsorbent, T = 298 K, contact time 2 h
| Nanoadsorbent | Metal | Sludge sample [mg/kg of dried matter] | Treated sludge sample [mg/kg of dried matter] | Removal efficiency [%] | Adsorption capacity (mg metal/g nanoadsorbent) |
Sewage Sludge Directive for use in agriculture 86/278/EEC* [mg/kg of dried matter] |
Official Gazette the Republic of Slovenia, No. 99/13 in 56/15 |
|
|---|---|---|---|---|---|---|---|---|
| 1. quality class of compost [mg/kg of dried matter] |
2. quality class of compost [mg/kg of dried matter] |
|||||||
| MNPs@SiO2@GOPTS-Lys | Zn | 733 | 687 | 6 | 17.2 | 2,500–1,200 | 400 | 1800 |
| Cu | 164 | 151 | 7 | 4.8 | 1,000–1,750 | 100 | 500 | |
| Cr | 44.3 | 34.4 | 22 | 3.9 | / | 100 | 500 | |
| MNPs | Zn | 733 | 711 | 3 | 8.8 | 2,500–1,200 | 400 | 1800 |
| Cu | 164 | 157 | 4 | 2.8 | 1,000–1,750 | 100 | 500 | |
| Cr | 44.3 | 42.5 | 4 | 0.7 | / | 100 | 500 | |
*reference [10]