Abstract

This study focused on the impact of microalgal biomass on the oil behavior in a sand-water system. The microalgal biomass was characterized and the interaction between microalgal biomass and oil was analyzed through FTIR. The effects of different conditions including microalgal biomass dose, pH, temperature and salinity on the oil behavior were investigated. A two-level factorial analysis was also used to further explore the interactions of these conditions. The microalgal biomass was found to be the most influential parameter for the residual crude oil on sand. Higher microalgal biomass dose resulted in less residual oil on sand. The remaining oil decreased with increasing solution pH from 4 to 7, and an increase of remaining oil was observed when the pH was further increased above 7. In addition, temperature and salinity could affect the removal of crude oil in the presence of microalgal biomass. Increasing the temperature up to 30 °C could result in less residual oil on sand compared with that at 5 °C. High salinity attributed to more oil removal from contaminated sand was more favorable than that at low salinity. Different mechanisms are related to oil removal and the behaviors of oil in this sand-water system could be influenced by the solution chemistry. The results of this study indicate that the presence of algae in the oiled shoreline can be considered in the comprehensive evaluation of spill risk and prediction of oil fate.