Título: Chemical Engineering JournalImportada do Authenticus Pesquisar Publicações da Revista

Vol. 285

Páginas: 709-717

ISSN: 1385-8947

Editora: Elsevier

ISI Web of Knowledge - 12 Citações

ISI Web of Science

Scopus - 21 Citações

INSPEC

FOS: Ciências da engenharia e tecnologias > Engenharia do ambiente

CORDIS: Ciências Tecnológicas > Tecnologia > Tecnologia ambiental

ID Authenticus: P-00G-VJ4

DOI: 10.1016/j.cej.2015.10.007

Abstract (EN): The present work focuses on the use of two different cork by-products, raw cork (RAC) and regranulated cork (RGC), as sorbents for oil and grease (O&G) removal from mineral oil-in-water (O/W) emulsions (lubricant oil 15W-40). Acidic conditions favored O&G removal from emulsions using cork granules, achieving values of about 90%. RGC showed the highest O&G removal capacity, associated with its thermal treatment with water vapor at 380 degrees C, which increased its hydrophobicity. Sorption isotherms at 25 degrees C were determined at different pH values (2, 4 and 6). Freundlich and linear models were able to fit well the equilibrium data regarding O&G removal using RGC, suggesting that the major sorption mechanism is partitioning (log K-ow around 4.0). Kinetic studies showed that O&G removal rates using RGC were faster (<100 min) than those using RAC (approximate to 1300 min). Moreover, oil sorption onto cork is favored by acidic conditions, achieving values of 90 mg g(-1) at pH 2 (equilibrium oil concentration in the liquid phase of 4.5 mg/L). In order to improve the oil uptake onto regranulated cork at near neutral pH, the use of different salts (NaCl, Na2SO4 and MgCl2) and surfactants (anionic: sodium dodecyl sulfate - SDS, cationic: hexadecyltrimethyl ammonium - HDTMA and nonionic: Tween 80) was tested. The best results were achieved using 0.1 M NaCl and Tween 80. This paper also proposes a mass transfer model based on cork and oil properties, which adequately predicts the kinetic experimental data and attests that the rate-limiting step in the sorption process is the external fluid film resistance.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9