Study on the mechanical strength and iodine adsorption behavior of coal-based activated carbon based on orthogonal experiments

To prepare coal-based activated carbon with high mechanical strength and adsorption performance for the removal of iodine from wastewater, the effects of carbonization temperature, heating rate, activation time and activator on the mechanical strength of activated carbon were studied; the optimal production conditions were determined by comprehensively considering the specific surface area, iodine value, compressive strength and wear resistance based on previous studies. Iodine adsorption kinetics and equilibrium adsorption experiments were carried out on activated carbon prepared under the optimum conditions. The results showed that the increase in mechanical strength was caused by the release of volatile matter and secondary reactions, which formed the carbon skeleton, while the decrease in mechanical strength was due to the intervention of the activator, which destroyed the carbon skeleton. The adsorption kinetics showed that a pseudo-second order kinetic model was more suitable for the adsorption behavior of iodine on activated carbon. The equilibrium adsorption experiment results showed that iodine was evenly adsorbed on the surface of activated carbon, and with increasing temperature, the affinity of the active sites of activated carbon to iodine also increased.