I am not sure I know what ACF is. However, if you want to determine the adsorption capacity of any sorbent, then model your results on Langmuir or Freundlich models (the most popular models). Alternatively you can model kinetics data of a sorbent using Lagegren pseudo first or second order equations. Check out my papers below:
1. Zaynab Aly, Adrien Graulet, Nicholas Scales, Tracey Hanley, “Removal of aluminium from aqueous solutions using PAN-based adsorbents: characterisation, kinetics, equilibrium and thermodynamic studies, Journal of Environmental Science and Pollution Research (2014) 21: 3972-3986. DOI 10.1007/s11356-013-2305-6.
2. Z. Aly and V. Luca, “Uranium extraction from aqueous solution using dried and pyrolyzed tea and coffee wastes”, J. Radioanaly. Nucl. Chem., Volume 295, issue 2, (2013) pages 889-900. DOI: 10.1007/s10967-012-1851-6.