In recent years, the inorganic nanoparticles played an important role in the membrane technology due to their special properties, most notably being the hydrophilicity/hydrophobicity modification of the active surface of the membrane. In this paper, the polymer used for membrane manufacturing was polysulfone (PSf) via phase-inversion method. The composite PSf membranes were prepared by blending zinc oxide (ZnO), titanium dioxide (TiO2) nanoparticles and ZnO/TiO2 nanohybrid with three concentrations. Retention of Congo red dye, distilled water permeability, relative flux and relative flux reduction were tested in order to study the effects of the nanoparticles in the membrane matrix. SEM, EDX, porosity, roughness, contact angle, tensile strength and elongation measurement were conducted in this article, also. Compared with control PSf, ZnO/PSf and TiO2/PSf membranes, the experimental results indicated that the ZnO/TiO2/PSf nanohybrid membrane presents the best overall properties, including permeability, retention, and antifouling ability. ZnO/TiO2/PSf membrane exhibits a percentage increase in permeability of 254% and retention of 64.58 % relative to that of the control PSf membrane.

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The activity of using membrane technology has developed fast in the treatment of wastewater, drinking water and process water production. The main challenges in membrane filtration are fouling reduction, permeability increase and high efficiency in retention. The best example of membrane enhancement is increasing hydrophilicity. Nanoparticles have been proven that their presence in the membrane matrix increases the water affinity significantly. Although the zinc oxide nanoparticles have a positive effect over the membrane performance, the influence of zinc oxide (ZnO) nanoparticle size has not been studied enough. Two sizes of nanoparticle of ZnO and three concentrations were used for the preparation of composite polysulfone ultrafiltration membranes. The effects of the ZnO nanoparticles in the membrane matrix on the permeation properties, flux stability and retention were tested. SEM, EDX, porosity and contact angle measurement were conducted in this article, also. The experimental results indicated that ZnO-PSf composite membranes exhibits significant differences in the membrane properties due to nanoparticle addition and regardless of their size it leads to an increase in hydrophilicity, flux, permeability, retention and porosity. Decreasing the nanoparticle size leads to an increase in membrane performance.

Membrane research has managed to reach ever greater heights. The optimization of membrane processes is of common interest to industry, research and the domestic environment. Nanomaterials have been progressively researched in the membrane sector within the last decade, contributing in particular to their beneficial properties for the prevention of membrane fouling. This research investigates the effect of two shapes of ZnO nanomaterials, respectively nanoparticles and nanowires, on the properties of ultrafiltration membranes composed of 25 wt.% polysulfone. The method of membrane manufacturing is phase inversion, the immersion precipitation technique, and the procedure of nanomaterial incorporation into the polymeric matrix is known as blending. The results demonstrated the positive influence of nanomaterials on the performance of membranes, regardless of their shape, compared to the control membrane. In terms of permeability, the membrane with addition of ZnO nanoparticles showed an increase of 207.19 %, while the membrane with addition of zinc oxide nanowires recorded an increase of 89.16%.

Water is an important element of life, while every industry in its processes uses an important amount of water. Following processes, the water is contaminated and requires water treatment technologies. Unconventional methods to wastewater treatment, in the last years, use membrane technology as one of the most reliable processes for contaminants removal. In this article, the influence of the different concentrations of polysulfone (PSf) on the polymeric membranes properties was studied. These membranes were obtained through phase inversion method and with different polymer concentrations: 23, 25, 27 and 30 wt.%. The performance of the membranes was studied by pure water flux, permeability and retention. It has been observed that by increasing the polymer concentration, the pure water flux and the permeability will decrease. Retention was determined using methylene blue, which is one of the most utilized dye from industry and it could be observed that by increasing the polymer concentration the retention degree of the pollutant also increases. In order to explain the evolution of membrane permeability at different polymer concentrations, surface hydrophilicity by contact angle method and cross-section SEM imaging were used.