Removal of endocrine disrupting chemicals from aqueous phase using spherical microporous carbon prepared from waste polymeric exchanger

A spherical microporous carbon adsorbent (CR-1), which was developed by carbonization and activation of the waste polysulfonated cation-exchanger, was used to remove Dimethyl phthalate (DMP) and 2, 4-dichlorophenol (2, 4-DCP) as the model compounds of EDCs from the aqueous solution. Four adsorption isotherm models, Langmuir, Freundlich, Toth and Polanyi–Dubinin–Manes equations were tested to correlate the experimental data, Toth and Polanyi–Dubinin–Manes isotherms models provided the best correlation. The Henry's law constants calculated from Toth equation were found to be 705.957 and 6,724.713 L g⁻¹ for 2, 4-DCP and DMP at 298 K, respectively, and the larger exponents n of the Freundlich model were 9.011 and 9.93 for 2, 4-DCP and DMP at 298 K, respectively. The values of Henry's law constants and exponent n of the Freundlich suggested that CR-1 was an effective adsorbent for removal of low concentrations of DMP and 2, 4-DCP from aqueous solution. Moreover, the adsorption kinetics results showed that adsorption of 2, 4-DCP and DMP on CR-1 was a pseudo-second-order process controlled by intra-particle diffusion and that adsorption uptake reached quickly half of equilibrium capacities within 20 min.