In Situ Combination of Covalent Organic Framework with Nonwoven for Efficient Removal of Organic Dyes

Industrial wastewater containing organic dyes has become a serious source of environmental pollution, threatening the ecological environment and human health. The adsorption method is important to treat dye wastewater because of its easy operation and high efficiency. Herein, TAP-BTCA-COF composed of benzene-1,3,5-tricarboxaldehyde (BTCA) and 1,3,5-tris (4-aminophenyl) benzene (TAP), a kind of covalent organic frameworks (COFs), was combined with viscose spunlaced nonwoven (VSN) via a simple in situ solvent–thermal synthesis to one step obtain TAP-BTCA-COF@VSN for the adsorption of organic dye in water. The results showed that TAP-BTCA-COF with a particle size of about 200 nm was uniformly distributed on the surface of VSN in a regular spherical structure. TAP-BTCA-COF@VSN exhibits versatile adsorption capacity toward both anionic dyes (congo red (CR) and methyl orange (MO)) and cationic dyes (methylene blue (MB) and rhodamine B (RhB)) in aqueous solution, with the highest efficiency for CR. The adsorption efficiency of TAP-BTCA-COF@VSN for CR reached 99.35% within 30 min when the adsorption temperature was 45 °C, the initial concentration of the dye solution was 20 mg/L, and the pH of adsorption solution was 7. After five repeated cycles of adsorption, the adsorption efficiency of TAP-BTCA-COF@VSN for CR remained 67.53%, demonstrating good reusability performance. Moreover, the adsorption mechanism of TAP-BTCA-COF@VSN for CR was better conformed to the Langmuir model and pseudo-second-order kinetics, suggesting that adsorption is predominantly governed by monolayer and chemical adsorption. This adsorption process proceeds spontaneously and is endothermic. Graphical The alternative text for this image may have been generated using AI.