TREATMENT METHOD FOR CHEMICAL MECHANICAL POLISHING WASTEWATER

摘要

PURPOSE: A treatment method for chemical mechanical polishing wastewater is provided which easily separates SiO2 particulate contained in wastewater generated in the chemical mechanical polishing process with a single layered filtration membrane and shortly backwashes the filtration membrane by forming a large sized low tackiness particulate aggregation. CONSTITUTION: The treatment method for chemical mechanical polishing wastewater comprises the steps of transferring wastewater generated in the chemical mechanical polishing process to a first rapid mixing tank(110), and agitating the materials by putting a calcium compound into the wastewater transferred to the first rapid mixing tank; transferring the wastewater in the first rapid mixing tank to a second rapid mixing tank(120), and agitating the materials by putting a cationic polymer coagulant into the wastewater transferred to the second rapid mixing tank; transferring the wastewater in the second rapid mixing tank to a third rapid mixing tank(130), and agitating the materials by putting alum into the wastewater transferred to the third rapid mixing tank; transferring the wastewater in the third rapid mixing tank to a fourth rapid mixing tank(140), and agitating the materials by putting an anionic polymer coagulant into the wastewater transferred to the fourth rapid mixing tank; and transferring the wastewater in the fourth rapid mixing tank to a slow mixing tank(200), and agitating the wastewater transferred to the slow mixing tank at a speed slower than an agitation speed in the fourth rapid mixing tank.