Sorption of perfluorooctanoate onto cyanobacteria from the eutrophic lake: effects of pH, heavy metals, and phosphate

The sorption of perfluorooctanoate (PFOA) onto cyanobacterial biomass is critical to understand its subsequent transport and fate in aqueous environments, but the sorption mechanisms remain largely unknown. This study aimed to investigate the influences of pH, heavy metals, and phosphate on the sorption of PFOA onto cyanobacterial biomass. Results showed that an increase in pH led to a decrease in PFOA sorption, which may be due to electrostatic repulsion. PFOA sorption first decreased, then gradually increased and surpassed the blank in the presence of Pb2+. However, PFOA sorption was suppressed in the presence of Cu2+, Cd2+, and . The possible mechanisms behind the impacts of pH, heavy metals and phosphate on PFOA sorption were also investigated using Ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectra. FTIR spectra analysis of the biomass suggested that heavy metal ions can complex with functional groups on the surface of cyanobacteria. Phosphate sorption blocked some of the available sorption sites on the surface of cyanobacteria, which contributed to the decrease in PFOA sorption. (c) 2016 American Institute of Chemical Engineers Environ Prog, 35: 1317-1323, 2016