High efficiency removal and recovery of an endocrine disrupting compound-bisphenol AF from wastewaters

Recent studies have shown the presence of endocrine disrupting compounds (EDCs) in surface water and sewage samples. A study on rapid removal of endocrine disrupting compounds (EDCs)-bisphenol AF (BPAF) on multi-walled carbon nanotube (MWCNT) is significant for understanding how wastewater containing trace recalcitrant or hazardous BPAF was treated. Besides, the sorption behavior and mechanisms remain largely unknown. In this study, it was found the adsorption kinetics equilibrium followed the pseudo-second-order model, while the adsorption isotherms fitted better with Langmuir equation, and the adsorption is a spontaneous and exothermic process. The adsorption process was controlled simultaneously by external mass transfer and intraparticle diffusion, but the external mass transfer processes played an important role in sorption of BPAF. Hydrogen bonds was the main driving force for the adsorption, and pi-pi stacking and hydrophobic interactions were probably extra important mechanisms to the adsorption of BPAF. The MWCNT have higher stability within eight removal-regeneration recycles and up to 95% of recovery could be obtained using ethanol elution. The results of the experiment verified effectiveness for the recovery and removal of BPAF from wastewater samples. (c) 2013 Elsevier B.V. All rights reserved.