Abstract Some oil fields produce from different reservoirs, which may be incompatible generating precipitates. These precipitates are often asphaltenes, which can be an emulsion stabilizing agent negatively affecting the oil treatment processes. In this work, the influence of oil incompatibility on the stabilization of water-in-oil emulsions was studied. Emulsions were evaluated from three different oils (A, B and C) and their mixtures (AB, AC, BC and ABC). The results showed that there is a relationship between separation kinetics of emulsions and asphaltene precipitation. The separation kinetics of the emulsions was faster for more compatible oils. We observed that oil A, which was the less stable regarding asphaltenes, and the ABC mixture, which was the most incompatible mixture, both presented the slowest kinetics of emulsion separation. On the other hand, mixture BC which had the highest compatibility among the other mixtures presented a faster kinetic of emulsion separation.

Resumen Campos petrolíferos producen a partir de diferentes yacimientos, que pueden ser incompatibles generando precipitado, que son a menudo asfaltenos, que pueden ser un agente estabilizador de la emulsión que afecta negativamente los procesos de tratamiento del petróleo. Este trabajo estudió la influencia de la incompatibilidad del aceite en la estabilización de emulsiones agua-en-aceite. Se evaluaron emulsiones a partir de tres aceites diferentes (A, B y C) y sus mezclas. Se concluyó que existe una relación entre la cinética de separación de las emulsiones y la precipitación de asfaltenos. La cinética de separación fue más rápida para los aceites más compatibles. El aceite A, que fue el menos estable con respecto a los asfaltenos, y la mezcla ABC, que fue la mezcla más incompatible, presentaron las cinéticas de separación de la emulsión más lentas. La mezcla BC que tuvo la mayor compatibilidad entre las otras mezclas presentó una cinética más rápida de separación de la emulsión.

Abstract Three methods to obtain isoprene oligomers were evaluated: chemical degradation of non-vulcanized coagulated natural rubber; chemical degradation of natural rubber latex; and oligomerization of the isoprene monomer. The products were characterized by infrared spectrometry (FTIR), nuclear magnetic resonance (NMR) and size-exclusion chromatography (SEC). All the three processes were efficient and can be controlled in order to obtain products with desired molar mass. Among the degradation processes, the reaction with the non-vulcanized rubber led to the purest products, but this process has the disadvantage of relatively higher catalyst cost of the catalyst. Reactions of isoprene with free radical initiation produced oligomers under specific conditions: low isoprene concentration, low initiator concentration, and xylene as solvent. The results discussed here allows the readers to have a chemistry overview and experimental insights about different chemical routes to obtain isoprene oligomers, compiled together in the same work. It shall be helpful for applied chemistry researches.

Resinas poliméricas porosas têm sido amplamente empregadas nos processos de tratamento de água devido a vantagens como elevada seletividade e possibilidade de regeneração e modificação química, permitindo a obtenção de um material com maior seletividade/especificidade. No presente estudo, resinas poliméricas porosas de metacrilato de metila-divinilbenzeno (MMA-DVB), estireno-divinilbenzeno (Sty-DVB) e estireno-divinilbenzeno sulfonada (S-Sty-DVB) foram sintetizadas, caracterizadas e avaliadas quanto à eficiência de remoção de petróleo e de anilina contidos na água. Nos testes empregando-se água oleosa, foram avaliadas colunas contendo somente um tipo de resina (Sty-DVB e S-Sty-DVB) e colunas contendo recheios mistos (MMA-DVB/S-Sty-DVB e Sty-DVB/S-Sty-DVB), frente à remoção de óleo e dos cátions sódio e cálcio presentes na água oleosa. As colunas com recheio misto apresentaram melhor desempenho, devido à diversidade de hidrofilicidade do sistema adsorvente, tendo sido possível remover uma gama mais extensa de contaminantes. A remoção de anilina presente na água foi possível com o uso da resina de estireno-divinilbenzeno sulfonada, em razão da reação ácido-base entre a anilina e os sítios ácidos da resina. Uma redução gradual, e não abrupta, da eficiência desta resina na remoção de anilina deve-se à interação de moléculas de anilina com o sal de anilínio formado após a saturação dos sitos ácidos da resina.

Polymeric resins have been widely used in water treatment processes due to their advantages, such as high selectivity and possibility of regeneration and chemical modification, allowing obtaining a material with greater selectivity/specificity. In the present study, porous polymeric resins of methyl methacrylate-divinylbenzene (MMA-DVB), styrene-divinylbenzene (Sty-DVB) and sulfonated styrene-divinylbenzene (S-Sty-DVB) were synthesized, characterized and evaluated for their efficiency in removing oil and aniline contained in water. In the tests with oily water, the efficiency in removing oil and cations of sodium and calcium was assessed with columns containing only one type of resin (Sty-DVB or S-Sty-DVB) and columns containing blended filling (MMA-DVB/S-Sty-DVB and Sty-DVB/S-Sty-DVB). The columns containing the mixture performed better, due to the diverse hydrophilicity of the adsorbent system, allowing removal of a wider range of contaminants. The removal of aniline from the water was possible with the use of the sulfonated styrene-divinylbenzene because of the reaction between the aniline and acidic sites of the resin. The efficiency of this resin in removing aniline declined gradually rather than abruptly, due to the interaction of the aniline molecules with the aniline salt formed after saturation of the resin's acidic sites.

Magnetic composites have a wide range of potential technological applications; however the evaluation of this material for extraction of phenolic compounds has not been sufficiently studied. Due to its high toxicity and solubility the removal of phenolic compounds from the aquatic environments has critical importance. In this work polymeric composites were prepared by anchoring Ni and Co particles on sulfonatedpoly(styrene-co-divinylbenzene) PS-DVB. The PS-DVB beads were synthesized by suspension polymerization and reacted with acetyl sulfate, aiming to obtain sulfonated copolymers. All materials were capable of removing phenol from aqueous solutions. The phenol adsorption kinetics was influenced by the polymer porosity and swelling capacity in water. The composite derivative of the more porous copolymer impregnated with nickel (C1SNi) was the most efficient in phenol removal, with the sorption equilibrium being established more rapidly than for the other composites. The pseudo second-order model was more adequate to describe the phenol adsorption process for the composite C1SNi. The Langmuir model describes successfully the phenol removal by this composite.