When most people think of waste recycling in restaurants, they probably think of recycling cardboard delivery boxes or composting some kitchen scraps or could be recovering cans and bottles after customers are done with them. What you may not think of as recycling material is waste grease. This is not necessary the leftovers of cooking oil that is to recycled into energy for powering engines, the grease referred here is the matter that winds up in a facility’s waste water. This includes water used for dish cleaning, floor drains, self-cleaning fume hoods drains and other sources where removal of grease to the surface is done and directed to the sewer system. Just like other waste, grease has a high and equal potential energy which can be converted to some useful products if recovered and properly treated.
The recycling process has various stages. The grease should first find its way into the sewer system. In South Australia, the restaurant owners should first get a permit from AS water for their waste water to be directly put in their sewer systems. Before the waste water passes reach the sewer system, it should pass through a grease interceptor or trap. These are large concrete containers fixed underground and have a capacity ranging from 400 to 900 liters. It is mandatory for all for all restaurants to contract a grease trap pumping and cleaning firm regularly or South Africa water enforced fines or a worse case close down the premises.
Once in the grease trap, waste water is given some time to settle. This allows grit and food particles sink while grease and oil float at the surface. Water then flows into next compartment and is allowed to settle for further separation of food particles and oil. The somehow clean water is then allowed to flow directly into the sewer system. In Adelaide, there are sewer pipes 8,700 km running underground its metropolitan area. Three waste water plants process 250 mega liters on daily basis at Adelaide.
Grease trap maintenance practices
The grease traps need regular cleaning after every three months which is usually done by liquid waste specialists. The grease trap cleaning process requires vacuum liquid truck. Grease trap cover is removed and hose pipe connected to it to pump the liquid waste into a truck. The grease trap is then cleaned by use of low-pressure water. Its cover is then replaced and sprayed with a perfume on the ground. The vacuum waste truck operator competes for the EPA and SA water documentation required and completes the grease truck cleaning process. This process is also used in the septic tanks for cleaning and pumping water.
Liquid waste water in the truck is taken to a treatment and processing plant. At signal waste and recycling, we have partnered with specialists to treat waste water removed from grease traps in Adelaide. Waste water is placed in concrete pits for the remaining water to evaporate. Sawdust is mixed with the greasy rubbish then peat moss and wood chips. The mixture is left for microbial activities. Once decomposition is complete, the residue is used as mulch foe agricultural activities. This leads to increased field yields which lead to the completion of the circle of the cycle. This process can however continue indefinitely.
Benefits of grease traps to restaurant owners
Environmental and economic benefits of the grease trap process include: the sewer will need less repairs and maintenance when these grease traps are used. Due to cooling and expansion of the grease can lead to sewer blockages leading into floods rivers, bay areas and business areas and use of grease traps will help to solve this problem. It is therefore economical to use grease traps and regularly and properly service them. In addition, it has led to job creation in Adelaide and SA in areas such as garbage removal whether in liquid or solid state.
Environmentally, grease traps benefits on garbage collection and recycling are two-fold (see our grease trap cleaning for the bay area). Liquid waste is cleaned before it gets into the ocean. Grease trap pumping and grease trap reduce nutrient runoffs in water catchment areas and oceans. When brought in treatment plant for composting and conversion to mulch, it serves a great deal in the agricultural sector. Agriculture is highly dependent on soil fertility for good yields of the food we consume. Not unless these nutrients are replaced in the form of fertilizers or mulch, plants will not effectively grow and reproduce.
So when you visit a restaurant and think of the grease trap underneath, remember how maintains the sewer flowing, reduce nutrient rich runoff, provide employment and enhance good generation.