Mechanisms of Fat, Oil and Grease (FOG) deposit formation in sewer lines

Impacts and managerial implications for sewer systems due to recent changes to inputs in domestic wastewater – A review

“…Mara et al (2001) reported that as much as 90% of grease interceptors installed in individual households in a Brazilian neighbourhood performed well, however, they speculated that user education still could be necessary. However, as calcium released from corroded concrete surfaces was found to be involved in the formation mechanism of FOG-deposits, He et al (2013) suggested the use of alternative material for the construction of grease interceptors. Many Scandinavian municipalities have been documented as informing the public of the dangers of e.g.…”

“…Studies carried out in the U.S have indicated that FOGdeposits essentially are composed of metallic soaps due to a saponification process involving calcium and free fatty acids (He et al, 2011;Keener et al, 2008). The most recent studies have largely supported these observations although they have also found greater diversification in compositional structure among FOGdeposits (He et al, 2013;Iasmin et al, 2014;Williams et al, 2012). As Western societal consumption patterns of diets rich in fats continues to increase during the 21st century (Food and Agriculture Organization of the United Nations, 2011), the fear among sewer managers that this would lead to increasing solids deposition in networks have been widespread (e.g.…”

Influences of Restaurant Waste Fats and Oils (RWFO) from Grease Trap as Binder on Rheological and Solvent Extraction Behavior in SS316L Metal Injection Molding

“…However the flow activation energy and moldability index shows that binder formulation of F2 is better which strongly indicates that the optimal feedstock formulation between PP and RWFO is a 20/20 volumetric ratio. This might be due to the contents of the stearic and oleic acids components inside the RWFO being less able to strongly influence the wettability of the feedstock [24]. It is also indicative that the RWFO can be used as a sustainable binder system in MIM and further improvement of the binder ratio can be done by additional stearic acids in the binder systems.…”

Problems, Control, and Treatment of Fat, Oil, and Grease (FOG): A Review

“…It is reported that an increase in the water hardness is associated with higher Ca levels in FOG samples 5 . Another study reported calcium leaching from concrete pipes to be the main source of increased concentrations of Ca in the FOG deposit samples 23 . However, based on the evaluations of vitrified clay pipes VCP , which are used in some countries such as Malaysia, it was found that FOG deposition is not due primarily to the presence of calcium, but can be related to other minerals such as sodium and potassium.…”

“…However, based on the evaluations of vitrified clay pipes VCP , which are used in some countries such as Malaysia, it was found that FOG deposition is not due primarily to the presence of calcium, but can be related to other minerals such as sodium and potassium. Moreover, the presence of high amounts of calcium and sodium in FOG deposits indicates that the deposit not only consist of FOG but also of metallic soaps formed during the hydrolysis reaction 5,23,24 . The aforementioned studies focused on the effect of calcium CaCO 3 on the formation of FOG deposits in sewer pipelines.…”