Conventional Ultrafiltration As Effective Strategy for Dye/Salt Fractionation in Textile Wastewater Treatment

Abstract

Use of tight ultrafiltration (UF) membranes has created a new pathway in fractionation of dye/salt mixtures from textile wastewater for sustainable resource recovery. Unexpectedly, a consistently high rejection for the dyes with smaller sizes related to the pore sizes of tight UF membranes is yielded. The potential mechanism involved in this puzzle remains unclear. In this study, seven tailored UF membranes with molecular weight cut-offs (MWCOs) from 6050 to 17530 Da were applied to separate dye/salt mixtures. These UF membranes allowed a complete transfer for NaCl and NaSO, due to large pore sizes. Additionally, these UF membranes had acceptably high rejections for direct and reactive dyes, due to the aggregation of dyes as clusters for enhanced sizes and low diffusivity. Specifically, the membrane with an MWCO of 7310 Da showed a complete rejection for reactive blue 2 and direct dyes. An integrated UF-diafiltration process was subsequently designed for fractionation of reactive blue 2/NaSO mixture, achieving 99.84% desalination efficiency and 97.47% dye recovery. Furthermore, reactive blue 2 can be concentrated from 2.01 to 31.80 g·L. These results indicate that UF membranes even with porous structures are promising for effective fractionation of dyes and salts in sustainable textile wastewater treatment.

Allochthonous and Autochthonous Halothermotolerant Bioanodes From Hypersaline Sediment and Textile Wastewater: A Promising Microbial Electrochemical Process for Energy Recovery Coupled With Real Textile Wastewater Treatment

“…Different TDWW treatment methods and techniques have been implemented and evaluated over the past two decades. These methods involve (i) physical methods (coagulationflocculation, adsorption, and filtration techniques), (ii) oxidation methods categorized as advanced oxidation processes (cavitation, photocatalytic oxidation, Fenton chemistry) and chemical oxidation using oxidizing agents (O 3 and H 2 O 2 ), and (iii) bioremediation methods (fungi, algae, bacteria) (Gosavi and Sharma, 2014;Yeap et al, 2014;Chandrakant et al, 2016;Chouchane et al, 2018;Jiang et al, 2018). For several reasons, such as eco-friendly, cost competitive, less sludge production, and giving non-hazardous metabolites or full mineralization (Hayat et al, 2015), the biological methods are qualified as the most sustainable method for wastewater treatment.…”

Hollow Fiber Ultrafiltration Membrane for Methyl Green Dye Removal

“…Membrane separation methods have displayed the most desirable alternative approaches, which can be utilized for a big-scale handling operation due to the benefits, like economical energy need, huge removal efficiency, environmentally friendly, room temperature operation, low investment, and less pollution, as contrasted with other popular separation systems [4,5]. Lately, the ultrafiltration membrane is employed in an extended diversity of fields, from the chemical industry, like the recovery of textile [6], processing of latex [7], lubricating oil recovery [8], and dyes removal [9][10][11], to the medical uses, like dialysis operations of the kidney [12], and even for biotechnology uses, like milk concentration [13], juice [14], protein recovery from cheese whey [15], and glue and gelatin [16]. There are various approaches to the classification of commercial dyes.…”

Investigation of electric field‐aligned edge‐oxidized graphene oxide nanoplatelets in polyethersulfone matrix in terms of pure water permeation and dye rejection

“…There is also a class of nanostructures entitled as DASNCs 1 and DASNPs 2 which have revealed improved performance for dye absorption when forming hybrid with rGO 59,60 . Actually, dye removal has attracted much attention in textile wastewater treatment in recent years, particularly using modified nano and ultrafiltration membranes 61‐65 …”