(702f) Towards Understanding Cake Formation and Filtration Characteristics for Enhanced Media Filtration in Effluent Waste Management

Understanding the engineering principles behind filter cake’s behaviors and its importance in many applications such as wellbore stability, oilfield waterflooding, drilling, produced water re-injection and/or disposal, and all solid-liquid filtration processes is crucial for successful implementation and maintenance of such operations. Many of the problems resulting from these operations are usually due to the inadequate understanding of filter cake mechanisms. Here, the effect of filter media porosity on specific cake resistance (a) from the suspended solids’ filtration data of a high-strength effluent is evaluated. The effect of porosity on a is discussed based on the results generated from successive filtration tests. The operating conditions featured transmembrane pressures (TMP) of 40, 80 and 120 kPa and microfiltration membranes with porosities of 0.1 and 0.2 µm. a, compressibility factor (𝛾), and fouling index (𝜗) are appraised, the data are corrected with Darcy’s law of cake filtration, and close correlations of the model was revealed based on the R² values. Moreover, the 𝛾 values obtained from the slopes of power plots (function of α and pressure gradient) are evaluated. The cakes are observed to be moderately compressible based on the 𝛾 values of 0.32 and 0.52 respectively obtained for 0.1 and 0.2 µm MF membranes. Furthermore, 𝜗 decreases as the porosity increases with the 0.1 and 0.2 µm MF membranes exhibiting 𝜗 values of 2.88E+09 and 1.44E+09 cm^-2, respectively. Physically at each instant of time, the porosity decreases throughout the cake from the cake surface to the membrane septum where it has the lowest value. It could therefore be concluded that the cake layer serves as a reliable and permeable secondary layer that sustains the flux, hence, sustainable productivity for longer filtration times. Furthermore, the approach of measuring the cake, and other filtration characteristics, provides a wealth of information, which greatly adds to our understanding of the mechanism of flux decline for consideration in every complex effluent treatment system involving filtration unit operations right from the process/plant design stages, for enhanced plant and process sustainability.