Efficient removal of tetrabromobisphenol A using microporous and mesoporous carbons: The role of pore structure

Abstract

Abstract Tetrabromobisphenol A (TBBPA) is a widely used flame retardant yet a persistent pollutant in the environment. In this study, various microporous and mesoporous carbon-based materials were synthesized and their adsorption performance toward TBBPA was systematically evaluated. The adsorbents were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, Raman spectroscopy, N2 adsorption/desorption and Zeta potential measurements. TBBPA adsorption over coal-based activated carbon (F300), coconut-shell-based activated carbon (AC) and CMK-3 followed Freundlich adsorption model, while TBBPA adsorption over zeolite-templated carbon (ZTC), single-walled carbon nanotube (SWNT) and multiwalled carbon nanotube (MWNT) could be well described by both Freundlich model and Langmuir model. Compared with F300 and AC, TBBPA diffusion on ZTC and CMK-3 is faster because of their ordered pore structure and higher average pore size. The surface-area-normalized adsorption capacity of TBBPA was higher on ZTC, AC and F300 than on CMK-3, SWNT and MWNT, which can be attributed to the stronger micropore-filling effect with the microporous carbonaceous materials. The presence of humic acids had little effect on TBBPA sorption over ZTC, F300, CMK-3 and AC, while suppressed TBBPA adsorption on SWNT and MWNT were observed. In the column adsorption test, ZTC was capable of continuously treating synthetic wastewater stream, indicating that ZTC had great potential to be used as an effective adsorbent for TBBPA removal.