Table 4. Isothermal adsorption model of heavy metal on biochar

Feedstock		Carbonization temperature (℃)	Heavy metal	Isothermal adsorption model	Adsorption capacity (mg/g)	Ref.
Wood and waste wood	Eucalyptus	500	Cr (VI)	Freundlich model	160.93195.49258.11	[9]
Agricultural byproducts	Mangosteen shells	400	Cr (VI)	Sips modelPseudo-second-order model	212.40	[28]
	Peanut shell	700	Fe (Ⅲ)	Pseudo-second-order modelFreundlich model	7.03	[29]
			Cr (VI)		9.09
	Rice straw	350550	Pb	Langmuir	0.800.85	[16]
		550	Zn	Langmuir	0.61
	Corn waste straw	600800	Cd (Ⅱ)	Freundlich	0.571.75	[15]