Co-immobilization of Chaetoceros calcitrans MZB-1 and culture medium in alginate beads for bioremediation of perfluorooctanoic acid and perfluorooctanesulfonic acid in seawater.

This study investigated the performance of immobilized Chaetoceros calcitrans MZB-1 for the removal of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from seawater. The optimal conditions for preparing immobilized alga MZB-1 were as follows: sodium alginate (SA) concentration, 2%; calcium chloride (CaCl2) concentration, 3%; initial algal inoculation density, 5 × 106 cells/mL; and culture medium, 2F. Across all levels of environmental factors (temperature, pH, salinity, and light intensity), the removal efficiencies of PFOA and PFOS by the immobilized alga were consistently 6%-10% higher than those achieved by the free alga. Furthermore, the immobilized alga exhibited high storage stability at 4 °C over a 60-d period. Preliminary studies based on microcosm experiments showed that immobilized alga could continuously remove PFOA and PFOS in seawater for more than 60 d, with net removal efficiencies of 48.7% and 50.9%, respectively. In addition, compared with treatments without the immobilized alga, the immobilized alga partially mitigated the decline in microbial richneess and diversity associated with PFASs. These results highlight the potential of immobilized alga MZB-1 for enhancing the removal of PFOA and PFOS in marine environments.