Abstract
Algae are widely used as biosorbent for the sorption of heavy metals, however sorption of oil on algae has not been explored. Algae in marine and fresh water environment may affect the fate and transport of spilled oil. Sorption of diesel and lubricating oil was studied using dead biomass of Spirulina sp. and Scenedesmus abundans. The rate and extent of sorption was studied in well mixed batch systems containing oil (0.1–2 %, v/v) and biomass (0.1 %) suspended in water. Sorption of diesel on Spirulina sp. was instantaneous. Rate limited sorption on algal biomass could be explained by the pseudo-second order model and equilibrium was established within 12 days. The Freundlich and Langmuir model could provide adequate fit for diesel sorption on algae but not for lubricating oil. A three parameter model, the Sips model, provided good fit for all the experimentally generated isotherms and yielded maximum sorption capacity of diesel and lubricating oil in the range of 12–14 g/g. Oil sorption on algae was comparable to other spill clean-up sorbents. Algae can be used for development of low cost sorbents and can facilitate removal of oil from contaminated water. Sorption is affected both by the type of oil and type of algae. This is the first study illustrating that the additives present in lubricating oil not only reduces the sorption rate but also alters sorption equilibrium such that two-parameter isotherms are inadequate. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13205-012-0056-6) contains supplementary material, which is available to authorized users.