Grease traps and septic tanks are commonly used in rural sewage treatment projects, and their shapes and uses are very different.

The function of the grease trap is to separate the suspended solids and water in different proportions in the sewage. Oil collection structures are mainly used in advection settling tanks. The oily sewage is fed to the oil collector from the rectangular frame according to the water pipe. The oil flows slowly in a horizontal direction and during the flow the finished oil is lifted to the river surface. The fuel oil and residual oil settled in the oil collector accumulate in the mud tank inside the tank and enter the mud pipe according to the discharge pipe.

Grease traps are usually used for catering wastewater treatment, such as restaurants, farmhouses, hotels, scenic spots and other catering wastewater in large quantities. The grease in the catering wastewater will float on the surface of the sewage, reducing the dissolved oxygen in the water and seriously affecting the effect of domestic sewage treatment. At present, septic tanks are mainly used for rural toilet maintenance and simple treatment of toilet sewage.

Grease traps and septic tanks are both initial treatment facilities for sewage treatment projects. They are also very different in structure, material and installation form. Grease traps are primarily made of stainless steel. Restaurant grease traps need to be installed directly on the pipeline containing sewage and oily water, the sewage line can be aligned with the inlet and grill of the oil-water separator, other equipment can be connected to the pipeline, while the installation of the oil-water separator must be placed horizontally.

Currently, China's septic tanks are mainly made of fiberglass, polyester plastic and so on. Septic tanks are generally designed to be buried in the ground and installed at the front of the sewage network. Large particles of debris and dirt will be precipitated in the septic tank, septic tank for sewage treatment and purification efficiency is very low, outflow of septic tank sewage will be transported to the sewage treatment plant or decentralized sewage treatment equipment for further treatment.