Removal of Different Dye Solutions: A Comparison Study Using a Polyamide NF Membrane

Abstract

The removal of organic dyes in aquatic media is, nowadays, a very pressing environmental problem. These dyes usually come from industries, such as textiles, food, and pharmaceuticals, among others, and their harm is produced by preventing the penetration of solar radiation in the aquatic medium, which leads to a great reduction in the process of photosynthesis, therefore damaging the aquatic ecosystems. The feasibility of implementing a process of nanofiltration in the purification treatment of an aqueous stream with small size dyes has been studied. Six dyes were chosen: Acid Brown-83, Allura Red, Basic Fuchsin, Crystal Violet, Methyl Orange and Sunset Yellow, with similar molecular volume (from 250 to 380 Å). The nanofiltration membrane NF99 was selected. Five of these molecules with different sizes, shapes and charges were employed in order to study the behavior of the membrane for two system characteristic parameters: permeate flux and rejection coefficient. Furthermore, a microscopy study and a behavior analysis of the membrane were carried out after using the largest molecule. Finally, the Spiegler–Kedem–Katchalsky model was applied to simulate the behavior of the membrane on the elimination of this group of dyes.

Using Pressure-Driven Membrane Processes to Remove Emerging Pollutants from Aqueous Solutions

“…Table 2 shows the B s values for each salt solution assayed, which are very close to those obtained by previous authors [ 27 , 40 ].…”

“…When comparing the permeability values obtained for the different membranes with those reported in the literature, it is observed that they are approximately of the same order of magnitude [ 27 , 40 ].…”

“…It is clear that the removal efficiency depends on the membrane type and solute, and the interaction between them. Temperature, pH, pressure, and concentration also influence rejection [ 26 , 27 ].…”

Ibuprofen Removal by Graphene Oxide and Reduced Graphene Oxide Coated Polysulfone Nanofiltration Membranes

“…The active layers of native and modified membranes were analyzed, before and after finishing the experiments, by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), using a SEM HITACHI S-3500N apparatus (Hitachi High-Technologies Corporation, Tokyo, Japan), equipped with an EDX XFlash 5010 analysis system (Brukers AXS, Karlsruhe, Germany) [23].…”

Membranes for Water and Wastewater Treatment

“…Hidalgo et al [5] evaluated the performance of polyamide nanofiltration membrane on the removal of six different dyes. It has been proven that the chemical structure of the dyes has an important influence on the permeate fluxes and rejection coefficients obtained, these being the molecular volume and the length perpendicular to the maximum area the most relevant parameters.…”