Abstract

Techniques using membranes for the treatment of wastewaters 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. Polysulfone and polyurethane have complementary characteristics and are interesting in the context of membranes for industrial applications. In this sense, the aim of this work was to prepare and characterize polysulfone/polyurethane-based membranes and tested them with a simulated wastewater containing the reactive black dye and sodium chloride by pervaporation. In their manufacture, thermal treatment (at 60 °C) and photo-radiation treatment (using ultraviolet light) were also applied. The characterizations were performed using different analytical tools. 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 respect to the simulated wastewater treatment, all membranes reached 100% selectivity. Concerning the saline solution, the mean selectivity was around 98.5%. Moreover, 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 photoirradiated membranes the photo-graft reaction has occurred, among all membranes, the blend without any treatment stood out from the others, presenting the highest permeate flow of the simulated wastewater. Finally, 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.

摘要

与其他工艺相比，使用膜技术处理废水的技术通常可以提高处理后水的质量。其中，全蒸发除了具有低工作压力外，在选择性方面还具有优势，这可以防止堵塞问题。聚砜和聚氨酯具有互补的特性，在工业应用的膜方面令人感兴趣。从这个意义上讲，这项工作的目的是制备和表征聚砜/聚氨酯基膜，并通过全蒸发将其与含有反应性黑色染料和氯化钠的模拟废水一起进行测试。在制造过程中，还进行了热处理（在60°C下）和光辐射处理（在紫外光下）。使用不同的分析工具进行表征。一般来说，可以验证所有膜都具有致密层。通过热分析可以确定所指示的工作温度低于50°C。对于模拟废水处理，所有膜均达到100％的选择性。关于盐溶液，平均选择性为约98.5％。此外，渗透流值commercial在商用膜表示的范围内，从1.6到2.4 kg m^-2小时^-1。尽管对于光辐照膜而言，发生了光接枝反应，但在所有膜中，未经任何处理的共混物与众不同，在模拟废水中呈现出最高的渗透流。最后，结果表明，这些膜除具有通过全蒸发过程从水中去除盐分的潜力外，还能够从纺织过程中回收废水。