Adsorción de azul de metileno en solución usando zeolita natural impregnada con OG y OGr

Abstract

In the present work, methylene blue (MB) was adsorbed in solution using natural zeolite (Z) impregnated with graphene oxide (ZGO) and reduced graphene oxide (ZrGO) under different conditions. To do this, graphene oxide (GO) was synthesized using the modified Hummers method, reduced graphene oxide (rGO), using an ecological method, using ascorbic acid as reducing agent. Using a magnetic stirrer for 1.30 hours, the zeolite (500 and 1000 mg) was impregnated with 20 ml of GO and rGO at 10mg/ml, 5mg/ml and 2,5mg/ml. Subsequently, the materials were characterized by FT-IR and UV-visible spectroscopy, and their morphology by scanning electron microscopy (SEM). In addition, adsorption kinetics tests were performed for each nanocomposite, the effect of contact time (5, 10, 15, 20, 30, 60 and 120 min), pH (6, 7 and 9), MB concentration (25, 50, 75 and 10 ppm) and temperature (25, 40 and 60°C) were evaluated, the experiments were carried out in triplicate. The final concentration of MB was measured using UV-visible spectroscopy. Thus, studying the contact time after 120 min, a greater adsorption capacity of 97,87 mg/g and 89,345 mg/g was achieved for ZGO and ZrGO, respectively; this for ZOG (Z:1000mg and GO:10mg/ml) and ZOGr (Z:1000mg and rGO: 5mg/ml). When evaluating the effect of pH, a higher adsorption capacity (92,487mg/g) was identified at pH 9 for ZGO and 96,043mg/g at pH 7 for ZrGO. For the effect of concentration, the best results were obtained at 25ppm, for ZGO (20,78mg/g) and ZrGO (21,176mg/g). Varying the temperature, the best results were at 60°C for ZGO (21,759mg/g) and at 25°C for ZrGO (17,373mg/g). Finally, it is recommended to carry out more studies related to the factors that influence the impregnation of the zeolite with GO and rGO.