Development of a calcium alginate-cellulose nanocrystal-based coating to reduce the impact of oil spills on shorelines.

It is well known that oil stranded on shoreline substrates can be difficult to remove and cause serious environmental effects. To address this issue, a calcium alginate-cellulose nanocrystal (CA-CNC)-based coating with a unique surface structure and superhydrophobic properties was developed to reduce the extent of shoreline oiling. The results of batch washing test showed that not only did the introduction of CNC not reduce the oil removal efficiency; it also improved the environmental stability of the coating to resist the effects associated with seawater immersion and erosion (especially in the case of 0.4 wt% of CNC). The oil-repellent performance of the coated gravels implied that both oscillation time and oil concentration had almost no effects on the amount of adhered oil. Assessment of oiling prevention based on the laboratory shoreline tank simulator proved the coated gravel performed very well as more oil floated and less oil remained on substrates and penetrated into the subsurface. Biotoxicity analysis showed that the coating powders reduced impacts on the toxicity of the oil to algae at low doses. There is a good potential for the use of this CA-CNC based coating technique to improve shoreline oil spill response. [Display omitted] • A calcium alginate-cellulose nanocrystal-based coating approach was developed. • The coated gravels showed good performance of oil removal and repellence. • The coating exhibited environmental stability in immersion and erosion of seawater. • The feasibility of using coating for oiling prevention was proved in tank tests. • Biotoxicity analysis revealed the coating alleviated the toxicity of oil to algae. [ABSTRACT FROM AUTHOR]