RESUMO
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 (qmax) of SOH was obtained in 15â min and was 574.86â mgâ g-1 in oil-in-salt water emulsion and 525.92â mgâ 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.
Assuntos
Poluição por Petróleo , Poluentes Químicos da Água , Purificação da Água , Adsorção , Emulsões , Concentração de Íons de Hidrogênio , Cinética , Óleos , TermodinâmicaRESUMO
Pistia stratiotes is a common aquatic plant of the northern region of the state of Rio de Janeiro, and its use as adsorbent material was studied in the present work. The preparation process included washing, drying, grinding, and acid activation. The sorption potential for removal of the indigo carmine dye from aqueous solutions was tested under various conditions, such as initial concentration, contact time, and temperature. The tests showed that the obtained biosorbent showed good performance for dye removal with a maximum capacity of 41.2 mg/g. The kinetic studies revealed that the pseudo-second-order equation provided the best fit of the experimental data. The Freundlich isotherm provided the best fit of the experimental sorption data for the system under study. The results obtained show that Pistia stratiotes has great potential to be used as biosorbent for the removal of dyes from aqueous solutions.