Table 1.

Physico-chemical characterization of rice straw biochar.

Parameter measured	Value
pH	9.3
Basic gps (meq/g)	7.8
Acidic gps (meq/g)	1.8
Ash%	50
Density (g/cm3)	0.28
Surface area (S BET ) (m2/g)	100
C wt%	53
H wt%	3.0
N wt%	1.5
O	42.4
C/N	25
H/C	0.08
O/C	0.79
Alkaline elements (ppm (ug/g) by dry weight)
K	14,000
Mg	3500
Na	2190
Ca	7354
Other essential elements mg/Kg
Fe	5754
P	2765
Heavy toxic elements mg/Kg
Zn	0.01
Mn	575
Al	4231
Cu	4
Cd	0.05
Pb	0.62
Hg	0.93