Electrospun Adsorptive Nanofibrous Membranes from Ion Exchange Polymers to Snare Textile Dyes from Wastewater

Abstract

legislated to minimize the discharge of industrial pollutants to protect freshwater resources. [2] One of the largest volumes and the most problematic types of wastewater is the effluent from the textile industry, whose water consumption can reach as high as 216 million m 3 day −1 . [3] Millions of metric tons of synthetic dyes are produced globally every year, with the main demand coming from the textile industry. [4] Exact numbers have not been established, but they surely exceed the commonly cited-even in 2020numbers of "100 000 dyes and 7.5 × 10 5 tons" as those appear as early as 1981. [5] Due to the incomplete binding of the dyes to the fabric material, it is estimated that a significant portion, around 5-20% of the total amount of dyes used remain in the effluent water. [6] The treatment of this dye-laden wastewater is essential for multiple reasons. Some dyes are directly and acutely toxic to the natural water ecosystem, but even those dyes that are not toxic absorb sunlight and thus decrease photosynthesis. [7] This effect, combined with the high oxygen demand from the decomposition of dyes, deprives natural waters of dissolved oxygen. Apart from environmental pollution, many dyes are toxic to humans and cause allergic reactions or even potential mutagenic or carcinogenic effects. [7] Biological and chemical treatment, membrane processes, and adsorption or a combination of these processes are used for the treatment of textile wastewater. Electrospinning technology has attracted attention for the production of adsorptive membranes due to the excellent control it provides over structural properties that can be tailored for specific applications. Owing to their high surface-to-volume ratio, high pore volume, low density, and increased flexibility compared with their film counterparts, [8] electrospun nanofibrous membranes are thus effective adsorbents that can scavenge pollutants. However, most polymers used in the preparation of electrospun membranes, such as cellulose acetate, poly(vinyl alcohol), poly(vinylidene fluoride), or poly(acrylic acid), either have poor adsorptive properties as stand-alone materials due to the lack of high-affinity binding sites or inadequate stability in water. They are therefore mostly used in composites with other materials, such as cyclodextrin [9,10] or polydopamine, [11,12] that provide binding sites for adsorption. Recently, Chen et al. tested multifunctional cellulose acetate nanofibers for the adsorption of ionic dyes. [13]

Chitosan/Zeolite Composite Aerogels for a Fast and Effective Removal of Both Anionic and Cationic Dyes from Water

“…Regarding the possible enzymatic routes, many microorganisms can degrade several pollutants, but their employment is often limited by technological constraint and reduced flexibility of the process [ 4 , 5 ]. Membrane filtration-based processes are commonly considered as very efficient even at high concentration, but the typical production of sludge requires frequent membrane replacement [ 6 , 7 , 8 ]. Adsorption is an easy, cost-effective and non-selective method suitable for the removal of a wide range of pollutants.…”

Electrospun Nanostructured Membrane Engineering Using Reverse Osmosis Recycled Modules: Membrane Distillation Application

“…[ 25 ]. Recent studies show the interest in the development of new nanofibrous membranes derived from ecological resources or using ion exchange polymers for the treatment of industrial and textile wastewaters as an increasingly essential research area [ 26 , 27 ]. For instance, treatment of RO brines by MD technology is one of the feasible solutions, enabling zero liquid discharge to the environment [ 28 ].…”

Adsorptive Removal of Anionic Azo Dye New Coccine Using Silica and Silica-gel with Surface Modification by Polycation

“…For developing countries, adsorption is one of the most suitable and effective methods for dye removal when using low-cost adsorbents such as minerals, clays or agricultural subproducts [2,16,17]. Various hybridized materials have been investigated for removal of dye through adsorption techniques, such as nanofibrous membrane [18] or porous g-C 3 N 4 nanosheet [19]. In order to produce novel adsorbents, materials can be modified by surface coating [20] or pre-adsorption with active chemical agents [21].…”