Modification and application of mesoporous carbon adsorbent for removal of endocrine disruptor bisphenol A in aqueous solutions

Bisphenol A (2,2-bis(4-hydroxyphenyl) propane, BPA) is a typical endocrine disruptor in aquatic environment. The removal of BPA by adsorption is a simple and effective way. Mesoporous carbon (MC) and N-modified mesoporous carbon (NMC) were synthesized by the soft template method and used for BPA adsorption. The adsorption performance of MC and NMC was investigated by the batch and dynamic system, and compared with commercial activated carbon (AC). Additionally, the kinetics and isotherms of BPA adsorption on MC and NMC were also investigated. The specific surface areas and average pore sizes of MC and NMC were 687.8 and 579.6 m(2)/g, 4.06 and 4 nm, respectively. The equilibrium adsorption capacity of MC and NMC was positively correlated with the initial BPA concentration, and negatively correlated with adsorbent dosages. The pH value of 3-8 was conducive to the adsorption of BPA on MC and NMC. Pseudo-second-order kinetic model and Freundlich isotherm model provided well fit for BPA adsorption on MC and NMC. Compared with AC, MC and NMC exhibited a higher adsorption capability and more stable recycling performance. In the dynamic adsorption tests, with the increase in BPA concentration and flow rate in the influent, the breakthrough time and saturation time are shortened. However, the increase in adsorption layer height extended the breakthrough time and saturation time.