Team:Warwick/Safety

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Safety

The UK is home to one of the oldest sewage systems in the world. Because of this it suffers from peculiar sewage problems. Fat-bergs are masses of fat, dirt and solid waste which form in old UK sewage pipes. These masses, which can come to weigh as much as 130 metric tons and span over 200 meters are caused by the dumping of cooking oil and wet wipes from commercial industries and the general public. The main component of fat-bergs is cooking oil, which coagulates solid debris into a mass stronger than concrete that can take months to remove! Our goal is to engineer a bacterium capable of digesting this oil, removing the root cause of fat-berg formations in UK sewers. This new approach allows for a long-term preventative strategy for fat-berg formation, which will drastically reduce costs, manpower and improve the environmental impact of fat-berg removal.

What causes fatbergs?

Fatbergs are caused by a mixture of factors, this includes: the presence of liquid waste, solid waste and the chemical enviorment of the sewer. Liquid waste in this case refers to the dumping of lipids, such as cooking oil and grease. The most abundant oil by far is palmitic acid, which makes up 53% of fat in a fatberg, palmitic acid is said to originate from cooking oils such as palm oil and olive oil, however, it is also abundant in milk, cheese and meats. Solid waste is also a major component of fatbergs, several types of waste are present in a fatberg such as condoms, plastic wrappers and even syringes! The most important component by far - which gives fatbergs their cement-like strength - are wet wipes made of polypropylene. These wetwipes, which are marked as "flushable" by most companies do not degreade in the sewer and therefore buildup, constructing a polymer of polypropylene, fat and sewer water. By far the most important aspect of fatberg occurence is the effect of calcium ions with triglycerides, which cause a saponification reaction creating a solid lump, which is used as an attachment point attaching the proto-fatberg to the sewer walls and causing the accumulation of fatty acids, causing the fatberg to grow and harden.