Non-uniform distribution of adsorptive fouling along hollow fiber membrane: Characterization and quantification
Non-uniform distribution of adsorptive fouling along hollow fiber membrane: Characterization and quantification
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DOI：
10.1016/j.seppur.2018.05.043
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发表时间：
2018-10
影响因子：
8.6
通讯作者：
Situ Mu;K. Xiao;Huiju Fan;Chun Liu;Shuai Liang;F. Xiao;Xiaomao Wang;Xia Huang
中科院分区：
文献类型：
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作者：
Situ Mu;K. Xiao;Huiju Fan;Chun Liu;Shuai Liang;F. Xiao;Xiaomao Wang;Xia Huang
局部通量沿中空纤维膜长度分布不均匀，极易造成通量部分过载，加剧膜污染。深入分析其对污染的影响对膜的几何形状（如纤维长度、内径和外径）的设计至关重要。研究了局部通量分布影响下可溶性有机物对HF膜的吸附污染。通过荧光和接触角测量，观察了吸附污染物的不均匀分布。然后，通过将langmuirand线性吸附动力学纳入HF膜腔的流体动力学，建立了一个HF- thomas模型来描述动态吸附过程（游离/吸附浓度作为时间的函数）。模型拟合可以有效地确定典型多糖、蛋白质和腐植酸模型化合物的HF膜吸附参数（平衡和速率常数）。采用HF-Thomas模型进行扩展模拟，探讨不同膜几何形态下局部通量分布对污染物传质和吸附污染分布的影响。综合无因次因子λl（由纤维长度、内径和外径以及固有过滤阻力决定）显著放大了通量和吸附的不均匀性。因此，λ可作为高频膜设计的关键参数。根据本研究结果，从吸附结垢的角度考虑，为保证相对均匀性，建议采用λl< 1作为保守准则。
Non-uniform distribution of local flux along the hollow fiber (HF) membrane length poses a high risk of partially overloaded flux to exacerbate membrane fouling. In-depth analysis of its effect on fouling is critical to the design of membrane geometry (e.g. fiber length, inner and outer diameters). This study focused on HF membrane adsorptive fouling by soluble organic substances under the influence of local flux distribution. The non-uniform distribution of adsorbed foulant was experimentally observed via fluorescence and contact angle measurements. An HF-Thomas model was then developed to describe the dynamic adsorption process (free/adsorbed concentration as a function of time), by incorporatingLangmuirandLinearadsorption kinetics into the hydrodynamics of the HF membrane lumen. The model fitting was found to be effective in determining the HF membrane adsorption parameters (equilibrium and rate constants) of typical polysaccharide, protein, and humic acid model compounds. Extended simulation was conducted using the HF-Thomas model to explore the impacts of local flux distribution on foulant mass transfer and adsorptive fouling distribution under different scenarios of membrane geometry. The non-uniformity of flux and adsorption was found to be markedly amplified by a comprehensive dimensionless factor,λl(which derives from fiber length, inner and outer diameters, and intrinsic filtration resistance). Therefore,λlmay qualify as a critical parameter for HF membrane design. According to the results of this study,λl< 1 was recommended as a conservative criterion to secure relative uniformity from the perspective of adsorptive fouling.