LUT University, Department of Separation Science, P.O. Box 20, FI-53851, Lappeenranta, Finland.
Lund University, Department of Chemical Engineering, P.O. Box 124, SE-221 00, Lund, Sweden.
Sci Rep. 2020 Feb 25;10(1):3427. doi: 10.1038/s41598-020-59994-1.
Membrane fouling is the major factor limiting the wider applicability of the membrane-based technologies in water treatment and in separation and purification processes of biorefineries, pulp and paper industry, food industry and other sectors. Endeavors to prevent and minimize fouling requires a deep understanding on the fouling mechanisms and their relative effects. In this study, Brunauer-Emmett-Teller (BET) nitrogen adsorption/desorption technique was applied to get an insight into pore-level membrane fouling phenomena occurring in ultrafiltration of wood-based streams. The fouling of commercial polysulfone and polyethersulfone membranes by black liquor, thermomechanical pulping process water and pressurized hot-water extract was investigated with BET analysis, infrared spectroscopy, contact angle analysis and pure water permeability measurements. Particular emphasis was paid to the applicability of BET for membrane fouling characterization. The formation of a fouling layer was detected as an increase in cumulative pore volumes and pore areas in the meso-pores region. Pore blocking was seen as disappearance of meso-pores and micro-pores. The results indicate that the presented approach of using BET analysis combined with IR spectroscopy can provide complementary information revealing both the structure of fouling layer and the chemical nature of foulants.
膜污染是限制膜基技术在水处理以及生物炼制厂、制浆造纸工业、食品工业和其他领域的分离和净化过程中更广泛应用的主要因素。为了防止和最小化污染，需要深入了解污染机制及其相对影响。在这项研究中，采用 Brunauer-Emmett-Teller（BET）氮吸附/解吸技术深入了解在木质基料超滤过程中发生的孔级膜污染现象。通过 BET 分析、红外光谱分析、接触角分析和纯水渗透率测量，研究了黑液、热机械浆工艺水和加压热水提取物对商业聚砜和聚醚砜膜的污染。特别强调了 BET 用于膜污染特性描述的适用性。污染层的形成表现为中孔区域累积孔体积和孔面积的增加。孔阻塞表现为中孔和微孔的消失。结果表明，使用 BET 分析与红外光谱相结合的方法可以提供补充信息，揭示污染层的结构和污染物的化学性质。
