Membrane internal fouling due to foulant adsorption onto the pore walls is a critical aspect of fouling. The classical “standard blocking law” for internal fouling simplistically assumes instantaneous adsorption such that the adsorbed amount grows linearly with the filtered liquid volume, which is inadequate to describe realistic internal fouling with varied adsorption rates. In this study, an extended standard blocking law for scenarios involving time dependent adsorption is proposed and yields an expression of the form dR/dV ∼ R^N (where R is filtration resistance and V is filtrate volume). Two ultimate scenarios of the law, i.e. the 1st-kind for sufficiently fast adsorption with the characteristic exponent N ≈ 1.5 (similar to the classical standard blocking) and the 2nd-kind for sufficiently slow adsorption with N ≈ 2.5 are experimentally verified via microfiltration of model polysaccharide (alginate) solutions using hydrophobic and hydrophilic membranes. Transition between the 1st-kind and 2nd-kind laws is related to the rates of adsorption versus filtrational mass transfer. The extended law provides an improved tool to evaluate internal fouling, particularly that associated with adsorption of hydrophilic matter (such as polysaccharides) into hydrophilic membranes.

由于污垢吸附到孔壁上而导致的膜内部结垢是结垢的关键方面。内部污垢的经典“标准阻塞定律”简单地假定为瞬时吸附，因此吸附量随过滤后的液体量线性增长，这不足以描述具有不同吸附率的实际内部污垢。在这项研究中，对于涉及随时间变化的场景吸附的扩展标准阻挡法提出并产生形式d的表达- [R / D V  〜  - [R ^Ñ（其中[R是过滤阻力和V是滤液体积）。法律的两种最终方案，即第一类为足够快吸附与特征指数Ñ ≈1.5（类似于经典标准阻塞）和第二实物用于吸附以足够慢Ñ ≈2.5通过使用疏水和亲水性膜模型多糖（藻酸盐）溶液微滤实验验证。第一类和第二类定律之间的转换与吸附速率与过滤质量传递速率有关。扩展法则提供了一种改进的工具来评估内部结垢，尤其是与将亲水性物质（例如多糖）吸附到亲水膜中有关的内部结垢。