Table 1 Properties of biochars used in this study

Original feedstock

Wheat bran pellets

Coppiced woodlands

Orchard pruning

Pyrolysis temperature (°C)

800

500

500

Particle size (mm)

1.7–2

1.7–2

1.7–2

BET specific surface area (m²/g)

55 ± 1

61 ± 1

13.7 ± 0.5

Electrical conductivity (S/m)

49.9

1.6

0.5

Total pore volume (cm³/g)

0.0445

0.0483

0.0165

Electron donating capacity (meq/g)

0.055 ± 0.01

0.199 ± 0.02

0.298 ± 0.02

Electron accepting capacity (meq/g)

0.434 ± 0.05

0.104 ± 0.01

0.404 ± 0.01