State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
Water Res. 2020 May 15;175:115649. doi: 10.1016/j.watres.2020.115649. Epub 2020 Feb 26.
Increasing attention has been focused on the removal of micropollutants from contaminated drinking source water. However, low rejection efficiency and membrane fouling still inhibit further application of nanofiltration membrane in this field. Interesting results were found that the residual hydrolyzed-aluminum nanoparticles from supernatant after coagulation and sedimentation strongly improved the nanofiltration performance for micropollutant removal. A simulated raw water containing humic acids, micropollutants and kaolinite clay was employed to investigate the factors of water matrix affecting the nanoparticle-enhanced nanofiltration for micropollutant removal. Results of experiments showed that these hydrolyzed-aluminum nanoparticles easily induced the aggregation of bisphenol-A (BPA) and humic acids in the supernatant. The enhancement of BPA removal was mainly attributed to the repelling interaction between the Al-BPA-DOC complexity and in situ-modified membrane surface during nanofiltration. 'This in situ surface modification by the hydrolyzed-aluminum nanoparticles improved membrane hydrophilicity, roughness and positively-charging capacity. For the treatment of River Songhua water spiked with micropollutant, the percentage removal of BPA was improved to be 88.5%, much more than the case of single nanofiltration without coagulation (60.7%). Meanwhile, the membrane fouling was reduced by 2.13 times than the case of single nanofiltration without the dynamically deposited-layer of nanoparticles. This in situ modification of nanofiltration membrane by hydrolyzed-aluminum nanoparticles achieved excellent removal efficiency for micropollutants from River Songhua water background.
人们越来越关注从受污染的饮用水源水中去除微量污染物。然而，低截留率和膜污染仍然抑制了纳滤膜在这一领域的进一步应用。有趣的结果发现，混凝和沉淀后上清液中残留的水解铝纳米颗粒强烈提高了纳滤去除微量污染物的性能。采用含有腐殖酸、微量污染物和高岭土粘土的模拟原水，研究了水基质因素对纳米颗粒增强纳滤去除微量污染物的影响。实验结果表明，这些水解铝纳米颗粒容易诱导上清液中双酚 A（BPA）和腐殖酸的聚集。BPA 去除的增强主要归因于纳滤过程中 Al-BPA-DOC 复合物与原位改性膜表面之间的排斥相互作用。这种水解铝纳米颗粒的原位表面改性提高了膜的亲水性、粗糙度和带正电荷的能力。对于松花江原水微污染物的处理，BPA 的去除率提高到 88.5%，远高于未经混凝的单一纳滤（60.7%）的情况。同时，与未经纳米颗粒动态沉积层的单一纳滤相比，膜污染减少了 2.13 倍。这种通过水解铝纳米颗粒对纳滤膜的原位改性实现了对松花江背景水中微量污染物的优异去除效率。
