Abstract

A novel surface-modified nanofiltration (NF) membrane was prepared by layer-by-layer (LbL) self-assembly of positively charged polyethylenimine (PEI) and glutaraldehyde (GA) and negatively charged carboxymethyl chitosan (NO-CMC) alternately on the polyethersulfone (PES) membrane surfaces. The alteration aimed at improving the membrane separation performance, which was investigated in the study. In order to enhance antibiological fouling performance of the NF membrane, the silver nanoparticles (AgNPs) were coated on the modified membrane in two different modes. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential measurement, and water contact angle measurements were employed to characterize the formed membrane surface chemical composition and morphology. The rejection of different single nonheavy metal salts, yielded from the modified membrane, followed the order of MgCl₂ > MgSO₄ > CaCl₂ > Na₂CO₃ > NaCl > Na₂SO₄. Additionally, the rejection of single heavy metal salts Cr³⁺, Cu²⁺, Cd²⁺, Ni²⁺ was 88.95%, 84.04%, 82.69% and 83.47%, respectively, whereas the rejection of Cr³⁺, Cu²⁺, Cd²⁺, Ni²⁺ increased to 91.77%, 90.70%, 89.74% and 87.22%, respectively, in the mixed salt solution. Moreover, the rejection of Cu²⁺ and Cd²⁺ increased to 96.12% and 94.38% after adjusting pH. As a result of loading the AgNPs on the modified membrane with a suitable mode, the antibiological fouling ability of the membrane was immensely improved by AgNPs.

Graphic abstract

中文翻译：

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使用层状自组装纳米过滤膜提高分离和抗生物结垢性能

摘要

通过在聚醚砜上交替交替交替地带正电的聚乙烯亚胺（PEI）和戊二醛（GA）和带负电的羧甲基壳聚糖（NO-CMC）进行逐层（LbL）自组装，制备了一种新型的表面改性纳滤（NF）膜。 （PES）膜表面。该变化旨在改善膜分离性能，该研究已进行了研究。为了增强NF膜的抗生物结垢性能，将银纳米颗粒（AgNP）以两种不同方式涂覆在改性膜上。傅里叶变换红外光谱（FTIR），X射线衍射（XRD），扫描电子显微镜（SEM），原子力显微镜（AFM），ζ电势测量，使用水接触角测量来表征形成的膜表面化学组成和形态。改性膜产生的不同的单一非重金属盐的排阻遵循MgCl的顺序₂  > MgSO ₄  > CaCl ₂  > Na ₂ CO ₃  > NaCl> Na ₂ SO ₄。另外，单一重金属盐Cr ³⁺，Cu 2 ⁺，Cd 2 ⁺，Ni ^2+的截留率分别为88.95％，84.04％，82.69％和83.47％，而Cr ³⁺，Cu ²⁺在混合盐溶液中，Cd 2 ⁺，Ni ^2+分别增加至91.77％，90.70％，89.74％和87.22％。此外，Cu ²⁺和Cd ²⁺的排斥调整pH值后，分别增加到96.12％和94.38％。由于以合适的方式将AgNPs负载在改性膜上，AgNPs大大提高了膜的抗微生物结垢能力。

图形摘要