Estudo cinético e de equilíbrio de adsorção de petróleo utilizando fibras de coco pré-tratadas

Abstract

The recent oil spill off the Brazilian coast serves as an alert for research to be carried out that includes biotechnological processes and products for cleaning marine environments. Therefore, this work aims to compare the use of residual coconut fibers (Cocos nucifera L.) in natura, pretreated with Protic Ionic Liquid (PIL) [2-HEA] [Ac] (innovative treatment) and by mercerization/acetylation (traditional treatment) as a biosorbent of petroleum spilled in the marine environment in a hydrodynamic simulation on a laboratory scale. The study of the kinetics and adsorption equilibrium were performed to determine the limiting mechanism of adsorption, as well as the maximum petroleum adsorption capacity for the coconut fibers studied. Characterizations of the fibers were carried out using SEM and FITR, and the kinetics and sorption equilibrium tests with petroleum from the Campos Basin and saline water. It was possible to observe that a minimum time of 5 min of contact between the adsorbent and adsorbent is necessary for biosorption to occur. The fibers treated with PIL (4.63 g/g) had greater sorption capacity, the fiber in natura (3.62 g/g) less capacity and the fiber with mercerization/acetylation treatment (4.26 g/g) has sorption with intermediate values. The kinetic model that best fitted the experimental data was pseudo-second order, indicating chemosorption as the limiting step of adsorption. The sorption equilibrium model chosen was Sips, determining adsorption in multilayer (Freundlich) with low concentrations of petroleum and in monolayer (Langmuir) with high concentrations. Based on these results, it can be said that the coconut fibers (Cocos nucifera L.) treated have a greater capacity to adsorb petroleum than the fibers in natura, and the fibers treated with PIL [2-HEA][Ac] have greater sorption capacity, among those evaluated, to be used in oil spills.

Bioremediation of urban river wastewater using Chlorella vulgaris microalgae to generate biomass with potential for biodiesel production

“…The innovation of technologies for the development of new sources of renewable energy is of great relevance to meet the high demands of the whole society (Cardoso et al, 2020;Ramluckan et al, 2014;Moreira et al, 2013). The global concern to reduce the impact of greenhouse gas emissions, due to the serious environmental and human health consequences, as accentuate by the Paris Agreement signed at COP 21, further research is needed in the field of energy sustainability (Pragya et al, 2013), considering extremely important the generation of fuels through renewable sources, which would be biofuels.…”

Carvão ativado oriundo do mesocarpo do fruto da castanha de caju (Anacardium ccidentale) na remoção de corante em meio aquoso

“…Quanto a isoterma de Freundlich, trata-se de uma equação empírica com adsorção em sítios não uniformes. Neste sentido, a adsorção para este modelo ocorre com a formação de multicamadas (energias de adsorção diferentes) com forte interação entre moléculas (Cardoso, et al, 2020). Este modelo matemático é muito utilizado para descrever capacidade adsortiva de um determinado sólido em meio aquoso (Equação 4).…”