Table 4 Microalgae biomass and hydrochar carbon, oxygen, and nitrogen functionality as established using XPS spectra (at%).
From: Adsorption of organic contaminants of emerging concern using microalgae-derived hydrochars
Sample | Carbon | Oxygen | Nitrogen | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
C = C/C-C, C-Hx | C-O- | C = O | COO- | O-C, Al(OH)3 | O = C, CaCO3 | Ar-OH | Fe-N | Organic N | Protonated N | |
285.0 eV | 286.6 eV | 288.3 eV | 289.5 eV | 531.6 eV | 532.6 eV | 533.9 eV | 398.6 eV | 400.2 eV | 401.9 eV | |
Initial | 38.75 | 20.46 | 7.79 | 1.16 | 7.75 | 17.06 | – | – | 4.47 | – |
180 °C | 36.96 | 14.30 | 5.31 | 1.12 | 19.50 | 9.41 | – | 0.42 | 3.86 | 0.44 |
220 °C | 42.22 | 13.05 | 2.90 | 0.93 | 19.66 | 7.74 | – | 0.32 | 3.34 | 0.35 |
260 °C | 45.98 | 6.14 | 1.58 | 0.58 | 22.82 | 5.47 | 0.98 | 0.66 | 2.49 | 0.37 |
