Center for Membrane and Water Science & Technology, Zhejiang University of Technology, Hangzhou 310014, China.
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
Sci Total Environ. 2022 Oct 10;842:156661. doi: 10.1016/j.scitotenv.2022.156661. Epub 2022 Jun 11.
Polyamic acid (PAA) is a flexible polymer and has abundant valuable hydrophilic groups. Herein, we developed an ultra-low pressure ultrafiltration (UF) membrane by integrating PAA into the polyethersulfone (PES) matrix via the "in-situ polycondensation" method. PAA was well compatible with PES and distributed uniformly in the membrane. The introduction of PAA improved membrane hydrophilicity. Meanwhile, the membrane pore structures were also refined. The membrane exhibited an excellent permeability under ultra-low pressure due to its improvement of hydrophilicity and pore structures. Under 0.3 bar, compare with the water flux of PES membrane, PES/PAA membrane improved nearly 2 times (571.05 L/(m·h)), with a high BSA rejection (≥90%). Even under a lower pressure, 0.1 bar, >300 L/(m·h) still can be achieved. Interestingly, the membrane we developed could maintain a high performance after drying, and then is very suitable for dry preservation. PES/PAA membrane showed a high oil removal (≥92%) and could remove oil from water effectively. Besides, the membrane exhibited excellent anti-oil-fouling properties. The flux recovery rate of PES/PAA (70.0%) far exceeds that of PES (37.9%) after three filtration and cleaning cycles. The membrane we developed is very valuable in oily wastewater treatment.
聚酰胺酸（PAA）是一种柔韧性聚合物，具有丰富的有价值的亲水基团。本文通过“原位缩聚”法将 PAA 整合到聚醚砜（PES）基质中，开发了一种超低压力超滤（UF）膜。PAA 与 PES 具有良好的相容性，在膜中均匀分布。PAA 的引入提高了膜的亲水性。同时，膜的孔结构也得到了细化。由于亲水性和孔结构的改善，该膜在超低压力下表现出优异的渗透性。在 0.3 巴下，与 PES 膜的水通量相比，PES/PAA 膜提高了近 2 倍（571.05 L/（m·h）），具有较高的 BSA 截留率（≥90%）。即使在较低的压力下，0.1 巴下，仍可达到>300 L/（m·h）。有趣的是，我们开发的膜在干燥后仍能保持高性能，非常适合干燥保存。PES/PAA 膜的除油率（≥92%）很高，可以有效地从水中去除油。此外，该膜还表现出优异的抗油污性能。在经过三次过滤和清洗循环后，PES/PAA（70.0%）的通量恢复率远远超过 PES（37.9%）。我们开发的膜在处理含油废水方面非常有价值。
