Preparação e caracterização de membranas de polisulfona-poliuretano para recuperação de água de processos têxteis industriais simulados

Abstract

Techniques using membranes for the treatment of wastewater usually promote higher quality of treated water when compared to other processes. Among them, pervaporation has advantages in terms of selectivity, in addition to low working pressure, which can prevent clogging problems. On the other hand, polysulfone and polyurethane have complementary characteristics that can confer the polymer blend, composed of these two polymers, interesting characteristics in the application of membranes on an industrial scale. In this sense, the objective of this work was to prepare and characterize membranes based on polysulfone / polyurethane and test them with a simulated effluent containing the reactive black dye and sodium chloride using the pervaporation process. In its manufacture, heat treatment (at 60 ° C) and photoiradiation treatment (with ultraviolet light) were also applied. The characterizations were carried out by analyzing physical, chemical, surface, morphological, physical-chemical and thermal properties. In general, it was possible to verify that all membranes have a dense layer. The thermal analysis allowed to define that the indicated working temperature is below 50 °C. With the simulated effluent (reactive black dye), all membranes reached 100% selectivity. With the saline solution, mean selectivity was around 98.5%. The permeate flow values were within the range presented by commercial membranes ranging from 1.6 to 2.4 kg·m-2 ·h-1 . Although, for the photo-radiated membrane, the photo-graft reaction occurred, among all membranes, the blend without any treatments stood out from the others, presenting the highest permeate flow of the simulated effluents. The results reveal that these membranes are capable of recovering wastewater from textile processes, in addition to having the potential to remove salts from water through the pervaporation process.[Resumo fornecido pelo autor]