Optimization of Preparation of Activated Carbon from Ricinus communis Leaves by Microwave-Assisted Zinc Chloride Chemical Activation: Competitive Adsorption of Ni²⁺ Ions from Aqueous Solution

Table 4

Adsorption isotherm parameters for adsorption of Ni²⁺ ions onto ZLRC.

Isotherm model	Parameters
	𝑄𝑚 (mgg^−1)	250
Langmuir	𝑏 (Lmg^−1)	0.0851
	𝑅^2	0.9990
	1/𝑛	0.3777
Freundlich	𝐾𝑓 (mgg^−1)	41.1147
	𝑅^2	0.9280
	𝛼 (Lg^−1)	0.0611
Temkin	𝛽 (mgL^−1)	45.960
	𝑏	54.811
	𝑅^2	0.9790
	𝑄𝑚 (mgg^−1)	177.237
Dubinin-Radushkevich	𝐾 (×10^−5 mol^2kJ^−2)	1.0000
	𝐸 (kJ mol^−1)	0.0709
	𝑅^2	0.8310