A three-mechanism (intermediate pore blocking, standard pore blocking and cake filtration) model considering correction of effective filtration area

A general three-mechanism (intermediate pore blocking, standard pore blocking and cake filtration) model considering correction of the effective filtration area based on Darcy's law, Hagen-Poiseuille equation and Hermes' law was firstly developed to describe the variation of trans-membrane pressure (Delta p(t)) in the constant flowrate cross-flow filtration mode by using EPS model solutions (bovine serum albumin (BSA), sodium alginate (SA) and humic acid (HA)). Results showed that the model predictions fitted well with the experimental data (the single EPS model solution (R2 >= 0.904), the binary EPS model solution (R2 >= 0.910) and the ternary EPS model solution (R2 >= 0.878)). For all model solution, the domination mechanism in the first stage was intermediate pore blocking, while that in the second stage was cake filtration. Meanwhile, higher flux or concentration would led to the transition point appear earlier, while higher cross-flow velocity made it appear later. Moreover, the predictive accuracy of the proposed model improved by 1.25 % compared with that without considering the correction of the effective filtration area. Also, the proposed model was also validated using other membranes (polyvinylidene fluoride (PVDF) and polyether sulfone (PES) membranes) (R2 >= 0.953) and other feed suspensions (yeast, kaolin and activated sludge suspensions) (R2 >= 0.981).