ABSTRACT

The objective of this paper was to propose a deepened analyze of a microfiltration membrane fouling by two biomolecules: a protein (Bovine Serum Albumin) and a peptide (Glutathione). In addition to an analysis of flux decline, the mass of biomolecules accumulated on the membrane during filtration was quantified and compared to adsorption experiments, using Fourier Transform Infra Red spectroscopy in Attenuated Total Reflection mode (ATR-FTIR). It was demonstrated that the same quantity of accumulated biomolecules on the apparent membrane area can generate totally different flux declines because of different fouling mechanisms. On the one hand, Glutathione can adsorb in the whole porous media of the membrane, penetrating through the pores, modifying the hydrophilicity at low concentrations and generating pore constriction at high concentrations. On the other hand, BSA organize a dense irreversible fouling in the first minutes of filtration containing a quantity equivalent to more than 45 monolayers, leading to pore blocking and pore constriction. This structure is resistant to rinsing and NaOH cleaning. Then a reversible fouling, containing a quantity equivalent to more than 90 monolayers is settled. The above structure can be removed with an intensive water rinsing and corresponds to a rather porous cake leading to a low resistance to water permeation, whereas the intermediate structure can only be removed with chemical cleaning and has a higher impact on water permeation. The original approach detailed in this paper allowed to go deeper in the understanding of the membrane fouling by soft matter, not detailed in previous papers.

摘要

本文的目的是对由两种生物分子引起的微滤膜污染进行深入分析：一种蛋白质（牛血清白蛋白）和一种肽（谷胱甘肽）。除了通量下降分析外，还使用衰减全反射模式 (ATR-FTIR) 的傅里叶变换红外光谱对过滤过程中积累在膜上的生物分子质量进行量化并与吸附实验进行比较。结果表明，由于不同的污染机制，在表观膜面积上积累的相同数量的生物分子可以产生完全不同的通量下降。一方面，谷胱甘肽可以吸附在膜的整个多孔介质中，穿透孔隙，在低浓度时改变亲水性，在高浓度时产生孔隙收缩。另一方面，BSA 在过滤的最初几分钟内会形成密集的不可逆污垢，其数量相当于超过 45 个单层，导致孔堵塞和孔收缩。这种结构耐漂洗和 NaOH 清洁。然后沉淀出含有相当于 90 多个单分子层的可逆污垢。上述结构可以通过强烈的水冲洗去除，并且对应于相当多孔的滤饼，导致抗水渗透性低，而中间结构只能通过化学清洗去除，并且对水渗透的影响更大。本文详细介绍的原始方法可以更深入地了解软物质造成的膜污染，这在以前的论文中没有详细说明。BSA 在过滤的最初几分钟内组织密集的不可逆污垢，其数量相当于超过 45 个单层，导致孔阻塞和孔收缩。这种结构耐漂洗和 NaOH 清洁。然后沉淀出含有相当于 90 多个单分子层的可逆污垢。上述结构可以通过强烈的水冲洗去除，并且对应于相当多孔的滤饼，导致抗水渗透性低，而中间结构只能通过化学清洗去除，并且对水渗透的影响更大。本文详细介绍的原始方法可以更深入地了解软物质造成的膜污染，这在以前的论文中没有详细说明。BSA 在过滤的最初几分钟内组织密集的不可逆污垢，其数量相当于超过 45 个单层，导致孔阻塞和孔收缩。这种结构耐漂洗和 NaOH 清洁。然后沉淀出含有相当于 90 多个单分子层的可逆污垢。上述结构可以通过强烈的水冲洗去除，并且对应于相当多孔的滤饼，导致抗水渗透性低，而中间结构只能通过化学清洗去除，并且对水渗透的影响更大。本文详细介绍的原始方法可以更深入地了解软物质造成的膜污染，这在以前的论文中没有详细说明。