TREATMENT OF WASTE WATER OF SILICON WAFER POLISHING

摘要

PURPOSE:To extent the life of an ultrafilter membrane and to make possible an inexpensive waste water treatment by subjecting the waste water contg. the pulverous silicon powder produced by polishing of a silicon wafer to an oxidation treatment prior to filtering the same with the ultrafilter membrane. CONSTITUTION:The waste water contg. the pulverous silicon powder produced by polishing of the silicon wafer is subjected to the oxidation treatment prior to the filtration of said water with the ultrafilter membrane in the stage of filtering the waste water with the ultrafilter membrane and separating the same to filter water and concd. water. The oxidation treatment refers to the contact of the water with gas such as oxygen or air having oxidizing power or the addition of an oxidizing agent such as hydrogen peroxide or sodium hypochlorite to the water and more particularly the oxidation treatment is executed to the extent of preferably =200mV oxidation reduction potential. The life of the ultrafilter membrane is extended simply by adding such simple treatment and the inexpensive waste water treatment is eventually made possible.