Table 4.
FTIR bands assignment of composite biosorbents with different kinds of wood.
| FTIR Band (cm−1) | Functional Group and Vibration Type | ||
|---|---|---|---|
| t1Pine-TB | t1Aspen-TB | t1Birch-TB | |
| 1739 | 1739 | 1739 | C=O stretching of unconjugated ketone, carbonyl, and aliphatic xylan groups |
| 1645 | 1640 | 1640 | C=O stretching conjugated to aromatic ring in wood and OH deformation of water in bentonite |
| - | 1595 | 1595 | C=O stretching conjugated to aromatic ring |
| 1510 | 1507 | 1507 | Aromatic structure stretching |
| 1463 | 1470 | 1470 | CH2 deformation stretching in lignin and xylan |
| 1425 | 1425 | 1425 | Aromatic structure combined with C–H in-plane deforming and stretching |
| 1385 | 1385 | 1385 | Aliphatic C–H stretching of methyl and phenol OH |
| 1317 | 1321 | 1321 | Guaiacyl and syringyl condensated units, aromatic ring breathing |
| 1270 | - | - | Guaiacyl ring breathing with C=O stretching |
| - | 1250 | 1250 | C–C and C–O stretching |
| 1160 | 1165 | 1165 | C–O–C stretching of pyranose rings, C=O stretching of aliphatic groups |
| 1111 | 1111 | 1111 | Antisymmetric in-phase ring stretching |
| 1040 | 1040 | 1040 | C–O deformation in primary alcohols, C–O stretch unconjugated, aromatic C–H in-plane deformation in wood and Si–O stretching in bentonite |
| 920 | 920 | 920 | Cellulose P–chains, C–H stretching out of plane of aromatic ring in wood and hydroxyl bending Al2OH vibration in bentonite |
| 798 | 798 | - | Si–O stretching of quartz and silica |
| 778 | 778 | - | Si–O stretching of quartz |