Emulsified oil separation by bioadsorption: a sustainable proposal

ABSTRACT

Oil emulsions are very stable, so both the treatment and the recovery of marine oil spills require expensive technologies, sometimes inefficient. Thus, studies of alternative methods for the treatment of oily effluents and phytoremediation are very important for sustainable development. The objective of this study was to use a chemically modified biomass of Salvinia sp. (SOH), for the removal of oil from oil-in-water emulsions. Initially, a chemical modification was carried out to remove interferences and to increase the adsorption capacity of the biomass. Physicochemical characterization tests were performed to understand the structure of the adsorbent produced as well as to verify changes going on the surface of the material. Adsorption tests were done, such as concentration variation, time, temperature and pH. The maximum adsorption capacity (q_max) of SOH was obtained in 15 min and was 574.86 mg g⁻¹ in oil-in-salt water emulsion and 525.92 mg g⁻¹, for oil-in-water emulsion. The isotherm model that best fitted was Freundlich model and for the kinetic model, the best fit was obtained with the intraparticle diffusion model. Thermodynamic studies indicate that SOH has physisorption, and the process is spontaneous and reversible.

GRAPHICAL ABSTRACT

KEYWORDS:

• Adsorption
• biomass
• oil-in-water-emulsion
• Salvinia sp

Acknowledgments

We extend our thanks to FAPERJ (Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro), to doctoral scholarship; and for Department of Inorganic Chemistry of the Institute of Chemistry of the Federal University of Rio de Janeiro for the infrared analysis of the biomasses of this study; and CETENE (Centro de Tecnologia Estratégica do Nordeste) for the analysis of surface area and porosity.

Disclosure statement

No potential conflict of interest was reported by the author(s).