Phycoremediation of coastal waters contaminated with bisphenol A by green tidal algae Ulva prolifera

The phycoremediation of coastal water contaminated with bisphenol A (BPA) by Ulva prolifera (U. prolifera) during green tide blooming was investigated. The results demonstrated that BPA could be removed rapidly in the presence of U. prolifera. >94.3% of BPA was removed by live U. prolifera while <2.5% of BPA was removed by dead biomass. The accumulation of BPA in U. prolifera was confirmed by laser confocal scanning microscopy (LCSM). Uptake experiments under different conditions showed that the removal efficiency of BPA by U. prolifera had positive relationships with light, nutrient and temperature while the salinity had no effect. A linear relationship existed between the removal efficiency and the BPA initial concentration when the BPA initial concentration increased from 50 to1000 μg L^-1, indicating the high tolerance of the green-tidal algae to the toxic effect of BPA. High BPA removal efficiency (>94%) was achieved at the environmental relevant concentrations of BPA. The field investigation indicated that the BPA concentration in the coastal water in the green tide blooming area was much lower than that in the adjacent coastal water without green tide. The contribution of the green-tidal algae in the removal of BPA in the coastal waters was remarkable due to the high BPA removal efficiency, and high biomass & huge covered area of the U. prolifera during the outbreak of green tide. These findings demonstrate a new important phycoremediation process for coastal water containing typical endocrine-disrupting chemicals (EDCs) during the green tide blooming.