TABLE 3.
Surface functional groups found in different biomasses.
| Biomass | Surface functional group | Wavenumber (cm-1) | References | |||
|---|---|---|---|---|---|---|
| Sugar can and orange peel biochars | C-OH stretch | 3,448 and 3,430 | Abdelhafez and Li (2016) | |||
| C=O stretch | 1637 | |||||
| C-C stretch | 1384 | |||||
| C-O stretch | 1101 | |||||
| C-OH stretch | 1101 | |||||
| Green taro | OH stretch | 3,763 | Elangovan et al. (2008) | |||
| NH2 stretch | 2325 | |||||
| Several bands from overtone and combination | 1920 | |||||
| C=O stretch | 1707, 1624 | |||||
| Ring stretch | 1487 | |||||
| Antisym stretch | 1404 | |||||
| C–O stretch | 1281 | |||||
| SO3 stretch | 1184 | |||||
| C–O stretch | 1019 | |||||
| C–CO–C bend | 655 | |||||
| Lignin | Stretching vibrations of aromatic and aliphatic OH groups | 3,412 | Guo et al. (2008) | |||
| C–H stretching | 2925, 2849 | |||||
| Carboxyl and carbonyl stretching | 1703, 1648 | |||||
| Aromatic skeletal vibrations | 1600, 1514, 1425 | |||||
| Aromatic methyl group vibrations | 1463 | |||||
| C–O stretching | 1329, 1217 | |||||
| Syringyl units | 1114, 827 | |||||
| Olive solid residue | ɣ(O –H) | 3,400 | Salem and Allia (2008) | |||
| ɣ(C –H) | 2900 | |||||
| ɣ(–NH) | 1500 | |||||
| ɣ(C=C) | 1700 | |||||
| ɣ(COO–,C=O) | 1037 | |||||
| Sawdust from Arundo donax | –OH group | 3,600–3,000 | Cukierman (2007) | |||
| C– O, C–C and C–OH bonds | 1000–1300 | |||||
| Seed hulls | –OH group | 3,600–3,000 | ||||
| C– O, C–C and C–OH bonds | 1000–1300 | |||||
| Sour orange residue | –OH groups | 3,423 | Khormaei et al. (2007) | |||
| CH stretching | 2925.88 | |||||
| C=O band | 1631 | |||||
| C–O carboxyl band | 1257–1244 | |||||
| Sugarcane bagasse | –OH group | 3,600–3,000 | Cukierman (2007) | |||
| C– O, C–C and C–OH bonds | 1000–1300 | |||||