Selective deposition of fine particles in constant-flux submerged membrane filtration

Membrane fouling due to dynamic particle size changes in the aerated hybrid PAC–MF system

“…Possibly the accumulated SS in R2 was not adsorbed in the way as they did on the membranes in R1 because of the presence of PAC, which lowered the resistance to filtration, delayed the TMP increase and extended the filtration cycle. In addition, Madaeni [44] and Hwang and Chen [45] demonstrated that higher resistance to filtration was caused by a less porous cake layer on the membrane. Therefore, the presence of PAC in R2 possibly altered the cake properties on the MF surface in a way that made the cake more favorable to filtration than that cake on the MF surface in R1, which was without PAC.…”

“…Although the porosity of the cake formed on the MF surfaces in three reactors was not measured in this study, our speculations here are supported by Madaeni [44], who observed variable porosities inside cakes on MF membrane using wide ranges of particle sizes and correlated the flux decline. Moreover, the drag forces due to suspension flow, permeate flow, and air bubble flow play the major role in determining the particle stability and cake porosity on the membrane surfaces [40,45].…”

Membrane fouling in a submerged membrane bioreactor: Impacts of floc size

“…primary property which generally exerts important roles in membrane fouling in MBRs. Some studies observed that the formed cake layer possessed a higher fraction of small sludge flocs as compared with bulk sludge [12][13][14][15][16]. These studies suggested that small flocs could more easily adhere to the membrane surface.…”

Influence of Mg2+ catalyzed granular sludge on flux sustainability in a sequencing batch membrane bioreactor system

“…It had an initial SVI 5 of 180 ml/g and a mixed liquor suspended solids (MLSS) concentration of 4.0 g/L. The synthetic wastewater used as influent in the three reactors contained NH 4 [21]. The pH of the wastewater was maintained at 7 by phosphate buffer.…”

“…However, the flux decline due to membrane fouling is the biggest challenge being faced by water technologists these days, as it decreases the membrane efficiency, resulting in increased operational and maintenance costs [2,3]. The organic and inorganic foulants in soluble, colloidal and particulate form not only deposit on the membrane surface but also inside the membrane pores [4]. This causes severe blocking of pores, and the membrane needs to be cleaned chemically, which itself is a costly and hazardous process [1,2].…”