Nanostructured all-cellulose membranes for efficient ultrafiltration of wastewater
Nanostructured all-cellulose membranes for efficient ultrafiltration of wastewater
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DOI：
10.1016/j.memsci.2022.120422
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发表时间：
2022-05
影响因子：
9.5
通讯作者：
Mengying Yang;Sarah Lotfikatouli;Yvonne Chen;Tony Li;Hongyang Ma;X. Mao;B. Hsiao
中科院分区：
文献类型：
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作者：
Mengying Yang;Sarah Lotfikatouli;Yvonne Chen;Tony Li;Hongyang Ma;X. Mao;B. Hsiao
利用超滤（UF）膜进行废水处理的一大挑战是其不可避免的生物污垢（从生物分子到微生物）趋势。为了克服这一挑战，本研究展示了具有亲水表面和高孔隙率（约 80%，无加压）的纳米结构纤维素膜。纤维素膜由注入纤维素纳米纤维（CNF）的莱赛尔微纤维支架组成，并与聚酰胺胺-环氧氯丙烷（PAE）交联。所展示的膜具有良好的机械强度（湿应力：3.5–8.0 MPa）、耐 pH 性（pH 2.5–9.0）和热水稳定性（60 °C）。与商用聚合物膜（例如聚偏二氟乙烯（PVDF）和聚醚砜（PES））相比，优化的纤维素膜表现出高渗透通量（127.6 ± 21.8 L m−2h−1bar−1）、优异的分离效率（>99.9%）、良好的通量恢复率（>95%）和废水过滤自修复能力。应用串联电阻和三种组合滤饼过滤模型来研究纤维素和 PVDF/PES 超滤膜的污染行为。虽然所有膜都存在滤饼层沉淀和孔堵塞问题，但由于 CNF 膜表面具有亲水性和带负电，因此在清洗后纤维素膜几乎表现出完全可回收性。这项研究说明了使用纤维素膜进行高效废水处理的巨大潜力，以及与现有商业膜相比其优越的防污性能。
One major challenge in utilization of ultrafiltration (UF) membrane for wastewater treatment is its inevitable tendency of biofouling (from biomolecules to microorganisms). To overcome this challenge, nanostructured cellulose membranes with hydrophilic surface and high porosity (∼80% without pressurization) was demonstrated in this study. The cellulose membrane consisted of a lyocell microfiber scaffold infused with cellulose nanofibers (CNF), crosslinked with polyamideamine-epichlorohydrin (PAE). The demonstrated membranes showed good mechanical strength (wet stress: 3.5–8.0 MPa), pH resistance (pH 2.5–9.0) and stability in hot water (60 °C). The optimized cellulose membrane exhibited high permeation flux (127.6 ± 21.8 L m−2h−1bar−1), excellent separation efficiency (>99.9%), good flux recovery ratio (>95%) and self-healing ability for wastewater filtration, compared with commercial polymeric membranes (e.g., polyvinylidene difluoride (PVDF) and polyether sulfone (PES)). The resistance-in-series and three combined cake-filtration models were applied to investigate the fouling behavior of the cellulose and PVDF/PES UF membranes. While all membranes suffered cake layer precipitation and pore blocking issues, the cellulose membranes exhibited near total recyclability upon washing due to the hydrophilic and negatively charged CNF membrane surface. This study illustrated the promising potential of using cellulose membranes for high-efficient wastewater treatment and its superior antifouling performance compared to existing commercial membranes.