Portal de Periódicos da CAPES

Artigo Produção Nacional Revisado por pares

BIBTEX RIS

Synthesis of activated carbon from oleifera moringa for removal of oils and greases from the produced water

2020; Elsevier BV; Volume: 14; Linguagem: Inglês

10.1016/j.enmm.2020.100357

2215-1532

Tayanara Menezes Santos, Felipe Abreu de Jesus, Gabriel Francisco da Silva, Luiz Antônio Magalhães Pontes,

Adsorption and biosorption for pollutant removal

In this study, activated carbon was developed from the seed (CS) and the pod (CV) of moringa oleifera to remove the oils and grease from the produced water in oil exploration. Activated carbons were prepared by pyrolysis at 600 °C and activation with NaOH. The adsorption experiments were performed in batch to optimize the influence parameters, such as adsorbent dose, contact time and temperature. The adsorption equilibrium for both carbons was reached in approximately 250 min. The maximum adsorption capacity of oils and greases was found using the dosage of 2.5 g L−1 for the initial concentration of oils and grease of 300 mg L−1. The kinetic data were applied to the intraparticle diffusion, pseudo-first-order and pseudo-second-order models. The thermodynamic analysis determined that the adsorption of oils and greases in CS and CV is spontaneous and thermodynamically favorable. As the temperature of the system increased, the absolute values ​​of Gibbs energy decreased, suggesting the downward trend of the adsorption process. The Gibbs energy of the CS was higher than that of the CV when under the same conditions, which indicates that the adsorption in the CS is more favorable. The negative enthalpy variation confirmed that the process is exothermic. In order to characterize the carbons, surface area analysis was performed, porosity characterization by scanning electron microscopy and Fourier transform infrared spectroscopy. Moringa oleifera biomasses proved to be efficient precursors for preparation of activated carbons, which were successful applied as adsorbent material for removal of oils and grease from the water produced.