Superhydrophilic microfibrous adsorbent with broad-spectrum binding affinity to effectively remove diverse pollutants from aqueous solutions

Abstract

The diversity of pollutants in wastewater, such as heavy metal ions, dyes, and antibiotics, has threatened the ecological environment and human health for decades. To tackle this harsh issue, we developed a superhydrophilic microfibrous adsorbent to remove diverse pollutants by functionalizing electrospun poly(glycidyl methacrylate) fibers with a high density of iminodiacetic acid (IDA) functional groups. Thanks to strong and broad-spectrum binding affinity of the IDA group and good surface wettability, the resulting superhydrophilic microfibrous adsorbent exhibits excellent adsorption performance toward cationic organic dyes, heavy metal ions, and antibiotics via electrostatic interaction or coordination. It can achieve extraordinarily high adsorption capacities of 2569.70 mg/g, 1621.49 mg/g, 2420.18 mg/g, 175.44 mg/g, 123.46 mg/g, and 389.53 mg/g towards methylene blue, malachite green, methyl violet, Cu2+, Cr3+, and tetracycline, respectively. The absorbent can realize more than 98 % removal rate of these pollutants from water within 20 min. Moreover, its porous membrane structure and pH-dependent adsorption selectivity provide the developed adsorbent with outstanding recyclability. The spent adsorbent can be easily regenerated via a dilute acid solution and reused at least 10 times without apparent loss in performance.