Wastewater from the slaughterhouse, after removing hair, skin, scum, and large suspended particles through a grate, flows into the grease trap. After removing most of the oil and sand, it then enters the equalization pond. The equalization pond ensures the normal operation of subsequent treatment facilities and achieves the designed effluent water quality, while also regulating water volume and equalizing water quality. The water from the equalization pond is then pumped to the horizontal flow flotation sedimentation unit.