. 2024 Mar 8;14:5692. doi: 10.1038/s41598-024-54307-2

Table 1.

Chemical characteristics of rice husk biochar produced from different pyrolysis conditions.

Samples	Pyrolysis conditions		pH (1:10, H₂O)	EC (dS m⁻¹)	Surface area (m² g⁻¹)	TC (%)	TN (%)	TH (%)	TO (%)	TP (%)	CaO (%)	K₂O (%)	MgO (%)	Na₂O (%)	H:C ratio (%)	O:C ratio (%)
Samples	Temp. (°C)	Time (min)	pH (1:10, H₂O)	EC (dS m⁻¹)	Surface area (m² g⁻¹)	TC (%)	TN (%)	TH (%)	TO (%)	TP (%)	CaO (%)	K₂O (%)	MgO (%)	Na₂O (%)	H:C ratio (%)	O:C ratio (%)
AB	330	15	6.10 ± 0.01^c	11.49 ± 1.62^a	2.55 ± 0.01^c	41.30 ± 0.01^b	0.40 ± 0.02^a	5.39 ± 0.11^a	34.61 ± 0.59^a	0.14 ± 0.03^a	0.08 ± 0.02^a	0.36 ± 0.12^b	0.04 ± 0.02^a	0.03 ± 0.01^a	1.55 ± 0.06^a	0.63 ± 0.32^a
NB	400	15	7.10 ± 0.02^b	9.50 ± 0.83^b	6.49 ± 0.03^a	44.10 ± 0.02^b	0.40 ± 0.02^a	5.32 ± 0.03^a	32.50 ± 1.33^a	0.16 ± 0.02^a	0.09 ± 0.03^a	0.47 ± 0.07^b	0.04 ± 0.01^a	0.03 ± 0.01^a	1.44 ± 0.02^b	0.55 ± 0.21^a
BB	600	30	11.01 ± 0.05^a	6.59 ± 0.13^c	5.30 ± 0.05^b	54.90 ± 0.19^a	0.60 ± 0.01^a	2.11 ± 0.03^b	5.88 ± 1.98^b	0.21 ± 0.01^a	0.16 ± 0.05^a	0.78 ± 0.09^a	0.07 ± 0.03^a	0.04 ± 0.01^a	0.46 ± 0.08^c	0.08 ± 0.09^b
p-value			**	***	**	**	***	**	***	*	*	**	***	***	**	***

AB acidic (pH 6.1) rice husk biochar; NB neutral (pH 7.1) rice husk biochar; BB basic (pH 11.0) rice husk biochar; EC electrical conductivity, TC total carbon, TN total nitrogen, TH total hydrogen, TO total oxygen, T-P total phosphorus.