Table 1 Variation of BET surface area, total pore volume and residual heteroatom with carbonization conditions

Palm kernel shell

500°C, 2 h

H₃PO₄

O-H, N?H, C = O, C = C, C?O?C, C?O?H, HC = CH

-

-

Treatment of greywater

[43]

Chicken bone

500°C, 2 h

KMnO₄

O-H, C = O, PO₄^3-

0.007

316

Removal of tetracycline and fluorescence dye

[36]

Leucaena leucocephala biomass

800°C, 1.5 h

NaOH, N₂

O-H, C-O, C = O

-

776

Removal of cadmium

[44]

Sorghum

900°C, 1.5 h

KOH, N₂

O-H, C-H, C-O, C = O

0.784

1430

Adsorption of methylene blue

[41]

Sugarcane bagasse

800°C, 1 h

KOH, N₂

O-H, C-C, C-H, C = C, C-O, C = O

0.5

692

Removal of naphthalene

[38]

Vitis vinifera leaf litter

600°C, 1 h

ZnCl₂, H₃PO₄, N₂

C-H, C = O, C = C

0.03

617

Adsorption of phenanthrene

[45]

Coffee waste

350°C, 3.5 h

HCl

O-H, N-H, C-H

-

-

Treatment of nitrate and nitrite fertilizers in industrial wastewater

[46]

Fruit shells

400°C, 1 h

N₂

O-H, C = O, C-H, C-O, C-C, C = C

0.235

579

Adsorption of methylene blue and ofloxacin

[47]

Hide waste

700°C, 1 h

K₂SiO₃

O-H, C-H, C-O, C = O, C = C, N-H, Si-N

-

1804

Removal of nickel (II) ions

[48]

High-pressure steaming hides waste

700°C, 1 h

K₂SiO₃

O-H, C-H, C-O, C = O, C = C, N-H, Si-N

-

1361

Removal of nickel (II) ions from water

[48]

Pineapple plant leaves

300°C, 1 h then 500°C, 1 h

H₃PO₄, N₂

O-H, C-H, C = O, C-O

1.270^a-fibres

1031

Adsorption of caffeine

[49]

Chestnut oak shells

450°C, 2.5 h

H₃PO₄, N₂

O-H, C-H, C-O, C = O

0.71

989

Removal of chromium (VI)

[39]

Rice husks

800°C, 2 h

KOH, CO₂

O-H, C-H, C = O, C = C, C ≡ C

1.126

1836

Removal of phenol

[40]

Date stones

660 W MV radiation, 8 min

K₂CO₃

O-H, C-C, C-O, C-X

0.656

1144

Adsorption of methylene blue

[50]

Cherry tree waste

650°C, 2 h

H₃PO₄,

O-H, C-H, C-O, C = O, C = C

0.558

738

Adsorption of cationic red 14 dye

[42]

Black wattle bark waste

500°C for 2 h 700°C, 4 h

ZnCl₂

O-H, C-H, C = O

0.064

414

Adsorption of phenol

[37]

Ganoderma lucidum bran

300°C, 3 h

ZnCl₂, N₂

O-H, C-H, C = C, C-O

0.03

18

Adsorption of copper ions

[51]

Ganoderma lucidum bran

300°C, 3 h

KMnO₄, N₂

O-H, C-H, C = C, C-O

0.11

832

Adsorption of copper ions

[51]