Remoción de ciprofloxacina en soluciones acuosas utilizando bagazo de caña de azúcar modificado con nanotubos de carbono

Abstract

The increasing occurrence of emergent pollutants in water bodies, such as ciprofloxacin (CPX), enhance the interest in the study of remediation processes. In this context, adsorption is widely used. Adsorbents can be economically outstanding biowaste or highly efficient specialized materials. The main objective of this research is prepare a composite, from sugarcane bagasse (SB) and carbon nanotubes, to study its applicability as an adsorbent in the removal of CPX. Material formation is verified by SEM, FTIR and XRD analysis. About characterization, the composite has a pHPZC = 6.46 with a proportion of active sites of 61.67%. The addition of oxidized carbon nanotubes increases the sorption capacity up to 20% compared with SB. Besides, pH values close to pHPZC, in the slightly acidic zone, enhance the sorption. Indeed, mechanism favorable to sorption are π-π interaction and low CPX solubility. In contrast, electrostatic repulsion in very acidic/alkaline condition and temperature increasing are unfavorable. In addition, the pseudo second order and Weber and Morris models represent the process kinetic. Finally, experimental data seems to fit Langmuir model with a qm = 16.835 mg·g-1 a 30°C, without disregarding Freundlich mechanism since the regression factor R2 is similar for both.