Síntese e caracterização de carvão ativado de vagem de Moringa Oleifera Lam e avaliação do seu desempenho na remoção de óleos e graxas

Abstract

The high volume and chemical composition of oily wastewater produced by the petroleum industry are a major problem in this sector, because .improper waste disposal may result in high ecological damage. Therefore, the treatment of this water is highly important, with many techniques being applied in the industry. A very widespread and effective technology used in water treatment contaminated by organic compounds is adsorption. In this context, this study investigated an application of three activated carbons in the removal of oil and grease present in the produced water. The precursor material was the Moringa oleifera Lam and the influence of activating agents such as zinc chloride (ZnCl2), phosphoric acid (H3PO4) and sodium hydroxide (NaOH) was investigated. The adsorbents obtained were characterized by the ash content, elemental analysis (CHN), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TG / DTG). The kinetic study showed that the equilibrium was reached around 10 minutes for all activated carbons. Additionally, the adsorbents were better represented by the pseudo-second order kinetic model. The sodium hydroxide activated carbon showed an unfavorable behavior to adsorption, while the phosphoric acid activated carbon showed a favorable behavior with adsorption capacity of 294.41 mg g-1 and removal efficiency equal to 95%. In addition, its chemical equilibrium was described by Langmuir isotherm, suggesting chemical adsorption. Freundlich isotherm adjusted well to experimental adsorption data for zinc chloride activated carbon, achieving a reduction in oil and grease content of 95%. The study indicated a great applicability potential of activated carbon with phosphoric acid for the removal of oil and grease from the studied effluent.