Sorption and removal of tetrabromobisphenol A from solution by graphene oxide

The sorption characteristics of tetrabromobisphenol A (TBBPA) on graphene oxide (GO) was investigated using batch experiments. Effects of contact time, pH, temperature, coexisting anions and humic acid (HA) were determined. The kinetics data indicated that TBBPA sorption process reached equilibrium within 10 h. In alkaline conditions and at higher temperatures, a large reduction of TBBPA uptake was observed. Major anions reduced TBBPA sorption in the order of NO3- < SO42- < HPO42- < HCO3-. Moreover, HA had obvious effect on TBBPA sorption. The results were shown that the sorption equilibrium could be well fitted by Langmuir model with maximum sorption capacity of 115.77 mg/g. The desorption hysteresis of TBBPA was obvious in the twice-cycle sorption and desorption experiments. Both pi-pi interaction interactions and hydrogen bonds might be responsible for the sorption of TBBPA on GO. TBBPA sorption could be well described by pseudo-second-order model. Thermodynamic parameters suggested that the sorption of TBBPA was exothermic and spontaneous process. (C) 2013 Elsevier B.V. All rights reserved.