Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.
School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China.
Environ Sci Technol. 2022 Dec 20;56(24):17998-18007. doi: 10.1021/acs.est.2c06397. Epub 2022 Dec 2.
Effective recovery of dyes and salts from textile wastewater by nanofiltration (NF) remains a serious challenge due to the high consumption of water and energy caused by the limited performance of the available membranes. Herein, a novel strategy is described to prepare loose polyester NF membranes by using renewable quercetin as the aqueous monomer for fractionation of high salinity textile wastewater with minimal water and energy consumption. Compared with NF270, taken as the reference membrane, the QE-0.2/TMC-0.2 membrane significantly improved the efficiency for dye/salt fractionation by 288%. The water consumption was also decreased by 42.9%. The efficiency is attributed to an ultrahigh water permeance of 198 ± 2.1 L m h bar with a high selectivity of 123 (extremely low NaCl rejection of 1.6% and high Congo red rejection of 99.2%). The optimal quercetin-based membrane had an ultrathin separation layer of about 39 ± 1.2 nm with good hydrophilicity and negative charge density. Moreover, this work includes a novel method of comparison with a theoretically ideal membrane, which shows that both the energy and water consumption are near their theoretical minimum. This strategy is expected to save energy and minimize carbon emissions for membrane-based wastewater treatment systems.
由于现有膜的性能有限，导致从纺织废水中回收染料和盐的过程需要大量的水和能源消耗，因此高效地通过纳滤（NF）从纺织废水中回收染料和盐仍然是一个严峻的挑战。本文提出了一种新的策略，即用可再生的槲皮素作为水相单体，制备疏松的聚酯纳滤膜，以最小的水和能源消耗对高盐纺织废水进行分级。与作为参考膜的 NF270 相比，QE-0.2/TMC-0.2 膜对染料/盐的分级效率显著提高了 288%。水的消耗量也减少了 42.9%。这种效率归因于超高的水渗透系数 198±2.1 L m h bar 和高选择性 123（NaCl 截留率极低，为 1.6%，刚果红截留率高达 99.2%）。基于最优槲皮素的膜具有约 39±1.2nm 的超薄分离层，具有良好的亲水性和负电荷密度。此外，这项工作还包括了与理论理想膜的新的比较方法，表明能量和水的消耗都接近理论最小值。该策略有望为基于膜的废水处理系统节省能源和最小化碳排放。
