Adsorptive Performance of Ni(II) from Aqueous Solutions Using Biochar Made of Phragmites australis by Adding Ammonium Polyphosphate as Flame Retardant

Table 1

Surface area, yields, and surface functional groups of the BC samples.

Samples number	(m^2/g)	Yield (%)	Carboxyl (mmol/g)	Lactone (mmol/g)	Phenolic (mmol/g)	Total acidic functional groups (mmol/g)
BC-300-0	4.6	29.5	0.1964	0.3217	0.5741	1.0922
BC-300-0.25	167.9	56.0	0.3011	0.3719	1.1727	1.8457
BC-300-0.5	164.3	58.6	0.3036	0.2936	0.8999	1.4971
BC-300-1.0	151.7	66.8	0.2992	0.3300	0.8419	1.4711
BC-400-0	7.9	25.1	0.1841	0.2709	0.6449	1.0999
BC-400-0.25	177.7	48.0	0.3661	0.3284	1.0713	1.7657
BC-400-0.5	181.2	53.8	0.3663	0.3575	0.9701	1.7121
BC-400-1.0	171.4	57.8	0.3858	0.3359	0.9469	1.6686
BC-500-0	12.1	16.5	0.0790	0.4102	0.4923	0.9815
BC-500-0.25	165.8	43.4	0.6180	0.1099	1.1835	1.9744
BC-500-0.5	149.5	50.4	0.3567	0.3615	1.0829	1.8012
BC-500-1.0	157.2	54.8	0.5329	0.1220	0.9919	1.6469