RESUMEN

A comparative study was conducted on the efficiency of mercury removal using bacterial nanocellulose (BNC) membranes obtained from the fermentation of the microorganism Komagataeibacter medellinensis, in contrast with its oxidized analog obtained by modifying the bacterial nanocellulose membranes via oxidation with 2,2,6,6-Tetramethylpiperidine-1-oxyl. Both types of membranes (modified and unmodified) were characterized to identify variations in the Physico-chemical parameters after modification. FTIR spectra confirmed the chemical modification of cellulose in all reaction conditions by the presence of a new characteristic band at ∼1730 cm-1, corresponding to the new carboxylic groups produced by the oxidative process, and the decline of the band at ∼1,650 cm-1, corresponding to the hydroxyl groups of the C6 carbon. While the XRD profiles indicated that the percentage of BNC crystallinity decreased and the SEM images showed that the nanoribbon network was interrupted as the amount of oxidizing agent increased. The kinetics of mercury removal from both types of membrane was evaluated by calculating the concentration of mercury at different times and establishing a mathematical model to describe the kinetics of this process. The modified membranes improved significantly the adsorption process of the metal ion and it was found that the modification that results in the greatest adsorption efficiency was BNC-m 7.5 with a value of 92.97%. The results obtained suggest that the modification of the bacterial nanocellulose membranes by oxidation transcendentally improves the mercury removal capacity, outlining the modified membranes as an excellent material for mercury removal in wastewater.

RESUMEN

Resumen En la actualidad existe un gran número de apósitos dada la amplia disponibilidad de biomateriales y principios bioactivos, por lo cual se hace necesario un consenso acerca de la clasificación de estos, para no generar confusiones a la hora de entender su utilidad y su idóneo manejo en el ambiente clínico. Por este motivo, en el presente artículo se hace una revisión bibliográfica utilizando las bases de datos SCOPUS, ScienceDirect y Web of Science, con ecuaciones de búsqueda que incluían las palabras clave de los diferentes tipos de apósitos. Con esta información se encuentra que los apósitos pueden ser clasificados de acuerdo con su complejidad, la naturaleza del material polimérico, su permeabilidad, su interacción biológica con la herida y su acción terapéutica, lográndose tener una definición detallada con todos las características relevantes para hacer una adecuada elección de un apósito. Adicionalmente, se incluye una revisión acerca del proceso de cicatrización y los tipos de heridas, dado que de esto dependen los fines terapéuticos y la selección de un apósito u otro.

Abstract Nowadays, there is wide variety of dressings because availability of biomaterials and bioactive components, thus a consensus is needed on their classification, to avoid in understanding their usefulness and their proper handling in clinical practice. Therefore, in this paper a bibliographic review is made using the SCOPUS, ScienceDirect and Web of science databases, with search equations which include the keywords of different types of wound dressings. With this information, we found that dressings can be classified according to their complexity, the nature of the polymeric material, its permeability, its biological interaction with the wound and its therapeutic action, in order to have a detailed definition with all the relevant characteristics to make a proper choice of a dressing. Additionally, a review about the healing process and the types of wounds is included, since this have an important influence on the therapeutic purposes and the correct selection of dressings.