Foulant-foulant Interaction of Combined Micro-particulate and Organic Fouling on a Ceramic Membrane

In this study, filtration performance and fouling tendency of organic matters mixed with micro-particles on ceramic microfiltration membrane were investigated by using a pilot filtration system. In the study, four types of organic matters (Humic Acid (HA); Bovine Serum Albumins (BSA); Sodium Alginate (SA); and Octanoic Acid (OA)) and two different sizes micro-particles (0.2 mu m and 0.4 mu m) were used as the representative organic and particulate foulants in secondary wastewater, respectively. The fouling mechanism of HA corresponded to pore blocking while fouling occurred by BSA and SA due to its adsorption on to the membrane pore adsorption and gel formation inside the membrane pore, respectively. The OA formed a thin hydrophilic layer that reduced the interaction between particles and the membrane and improved the permeate flux. When particles present in the solution, they were found inside the cake layers formed by organic matters on the ceramic membrane. These particles made the cake layers more porous. This helped in increasing the filtration time and the recovery rate of the membrane after physical backwashing. Conversely, particles were the main factors that create a flux decline in the filtration of OA on the ceramic membrane.