Elemental distribution of HA, HA–nitrapyrin, FA and FA–nitrapyrin.

Treatment	Element	Before adsorption			After adsorption
		wt (%)	wt sigma (%)	Atomic percentage (%)	wt (%)	wt sigma (%)	Atomic percentage (%)
HA	C	19.56	1.46	30.57	14.84	2.90	24.35
	O	35.26	0.67	41.40	21.05	0.91	32.11
	Na	1.15	0.06	0.94	4.03	0.13	3.71
	Al	5.90	0.12	4.11	6.55	0.17	4.80
	Si	34.72	0.66	23.25	25.74	0.60	18.75
	S	0.23	0.04	0.13	2.91	0.11	1.93
	Cl	0.77	0.05	0.41	1.85	0.07	1.13
FA	C	52.14	1.16	66.02	49.90	1.64	66.00
	O	28.24	0.73	26.85	26.14	0.87	25.90
	Si	0.09	0.02	0.04	0.20	0.03	0.12
	S	4.99	0.16	3.10	6.20	0.22	3.08
	Cl	0.86	0.05	0.47	2.00	0.08	0.90