A Study for Reclamation and Reuse of the Chemical Mechanical Polishing Wastewater in Semi-conductor Industry

• Main Authors: Yen-Min Chen, 陳彥旻
• Other Authors: H.Paul Wang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/66413608069886361858

碩士 === 國立成功大學 === 環境工程學系碩博士班 === 91 === Feasibility for treatment and reclamation of the Chemical Mechanical Polishing(CMP) wastewater by the Latin Square Design and Taguchi Method of experiment design were studied. The Jar tests of Ferric chloride and Dipolarization-induced Electro-coagulation process and reverse osmosis (RO) technology were used. In addition, in order to obtain useful engineering design, optimization of the process performance was also studied. The results show that the CMP wastewater could be treated suitably by Ferric chloride and coagulant aids ,A-101 ,when the concentration of Ferric chloride was 50mg/L as Fe, the dosage of coagulant aids A-101 was 1 mg/L and the pH value of the wastewater was at 5. The removal efficiencies of turbidity, true color, Dissolved Solid, Si, and SiO2 were approximately 98.9﹪,96.8﹪,89﹪,96.9﹪and 2﹪. The CMP wastewater, after treated by the Ferric chloride and coagulant aids, A-101 , can be reused in sprinkling, bathroom flushing and landscape utilization via further treatments of chlorization, ozonization or UV disinfection. Compared with the cooling water standards , the treated water could be used in cooling water except the concentration of SiO2,which is a little higher than the standard. The efficiency and cost analysis data showed that the CMP wastewater could be treated suitably by dipolarization-induced electrocoagulation process at the operational voltage of 120 volt ,the current density mode of 5 and the retention time of 29.2 sec. and the pH value was justified to 5 after the dipolarization-induced electrocoagulation process. The removal efficiencies of turbidity, true color, Dissolved Solid, Si and SiO2 were approximately 99.3﹪,97.6﹪,92.7﹪,97.7﹪and 39﹪,respectively. And the results implied that the removal efficiencies of dipolarization-induced electrocoagulation process were better than the Jar Tests of Ferric chloride. The CMP wastewater that was treated by dipolarization-induced electrocoagulation process can be reused in cooling water and sprinkling, bathroom flushing and landscape utilization via further treatments of chlorization, ozonization or UV disinfection. The qualities of treated water were close to the drinking water, so that it could be reused to the Deionized water treatment system. Nevertheless, in the RO process, the removal efficiencies for specific conductivity, Dissolved Solid, SO42-and SiO2 were greater than 98﹪.