Moreover, adsorption mechanisms of sulfate on different adsorbents are reviewed based on the intermolecular interaction, equilibrium, thermodynamic, and kinetic studies.  The thermodynamic studies showed that the sulfate adsorption is endothermic and spontaneous except for the sulfate removal by polypyrrole-modified activated-carbons and LDH-HPI mine waste, which requires energy for adsorption.
THERM