A study on Superconducting High-Gradient Magnetic Separation for Purification of CMP Wastewater Using Magnetic Seeding Aggregation Technique
- 주제(키워드) Superconducting HGMS system , Magnetic seeding aggregation , CMP wastewater purification
- 발행기관 고려대학교 대학원
- 지도교수 이해근
- 발행년도 2013
- 학위수여년월 2013. 8
- 학위구분 석사
- 학과 일반대학원 신소재공학과
- 원문페이지 65 p
- 실제URI http://www.dcollection.net/handler/korea/000000046597
- 본문언어 영어
- 제출원본 000045764541
초록/요약
With rapidly increasing demands for semiconductor devices, the purification of chemical polishing (CMP) wastewater has become greatly important for worldwide environmental protection. Conventional methods for the purification of the wastewater such as chemical coagulation, sedimentation and membrane filtration are able to purify a large amont of the wastewater. However, large-scale equipment and high capital investment are necessary. Recently, superconducting high gradient magnetic separation (HGMS) has received considerable attraction as a promising water purification technique due to its compact design and efficient and accurate removal of contaminants. This study examined the optimized coagulation process employing a magnetic seeding aggregation with respect dosages of ferric chloride and magnetite at various pH values to remove nanoparticulates from CMP wastewater using the superconducting HGMS system. Magnetic sedimentation tests demonstrates that nanoparticulates were effectively flocculated at pH 6 with 1.5 g/L of magnetite and 0.2 g/L of ferric chloride, leading to the lowest residual turbidity of CMP wastewater. In the filtration tests via the superconducting HGMS system, the turbidity of CMP wastewater, through the optimized coagulation process, decreased to 1.55 NTU, which was lower than the grey water standard (2 NTU). Therefore, the use of a superconducting HGMS system combined with the magnetic seeding aggregation technique would be a simple and cost effective solution to the problems of water pollution caused by the semiconductor industry.
more목차
1. INTRODUCTION
2. THEORETICAL BACKGROUND
2.1. Superconductivity
2.1.1. Definition of superconductivity
2.1.2. High temperature superconductors (HTS)
2.2. Superconducting high-gradient magnetic separation (HGMS) system
2.2.1. Introduction to HGMS system
2.3. Purification of chemical mechanical polishing (CMP) wastewater
2.3.1. Conventional methods for purification of CMP wastewater
2.3.2. Magnetic seeding aggregation and superconducting HGMS for purification of CMP wastewater
2.3.2.1. Coagulation and flocculation
2.3.2.2. Magnetic seeding aggregation
3. EXPERIMENTS
3.1. Characterization of CMP wastewater
3.2. Magnetic sedimentation test
3.3. Manufacture of HGMS system for purification of CMP wastewater
4. RESULTS AND DISCUSSION
4.1. Zeta potential measurement of silica and magnetite with respect to pH value
4.2. Optimization of coagulation process
4.3. Purification of CMP wastewater via superconducting HGMS system
5. CONCLUSION
