Sorption Behavior of Hexabromocyclododecanes (HBCDs) on Weihe River Sediment

Adsorption behaviour of tetrabromobisphenol A on sediments in Weihe River Basin in Northwest China

Tetrabromobisphenol A (TBBPA) is adsorbed on sediments in river environments, and various environmental factors have distinct effects on its adsorption behaviour. Investigating the adsorption behaviour of TBBPA on the sediments in Weihe River Basin is critical for protecting the water environment and providing a theoretical basis for the prevention and control of brominated flame retardant pollution. In this study, the adsorption behaviour of TBBPA on Weihe River sediment was investigated by conducting batch equilibrium experiments, and the effects of pH, dissolved organic matter, and ionic strength on the adsorption of TBBPA were discussed. The obtained results revealed that rapid adsorption was the main mechanism of the TBBPA kinetic adsorption process. The isothermal adsorption behaviour of TBBPA was well fitted by Freundlich model (R² 99.21%) than Langmuir model (R² 98.59%). The adsorption capacity for TBBPA is 34.13 mg/kg. The thermodynamic results revealed that the adsorption process of TBBPA by the sediment was a spontaneous endothermic reaction. The increase in pH and ionic strength inhibited the adsorption of sediments on TBBPA. With the increase in the humic acid concentration, the adsorption of TBBPA initially increased and subsequently decreased. Synchrotron radiation-Fourier transform infrared spectroscopy indicated that the adsorption mechanism of TBBPA on the surface of sediment was mainly π-π and hydrogen bonds. The obtained results are useful for understanding of TBBPA migration and transformation in river water bodies.